triptorelin
Triptorelin lowers testosterone or estrogen during sustained treatment. Its depot injections are used for advanced prostate cancer and central precocious puberty. Evidence for restoring testosterone after anabolic-steroid use consists of one case report, with one month of follow-up.
Synthetic decapeptide GnRH-receptor agonist
- US Trelstar is an intramuscular pamoate depot for advanced prostate cancer.
- US Triptodur is a 22.5 mg intramuscular pamoate depot given every 24 weeks for central precocious puberty from age 2.
- UK Decapeptyl SR 3 mg is an acetate depot with broader local indications and its own treatment limits.
- A 284-man randomized trial established testosterone suppression comparable to leuprolide after the first month.
- A 226-man China and Russia trial confirmed suppression after prostatectomy but did not significantly improve its primary biochemical-relapse endpoint.
- The post-cycle evidence remains one uncontrolled case with route and formulation missing from the indexed abstract.
Does triptorelin suppress hormones or restart production?
For labeled triptorelin depots, the clinical goal is sustained suppression after a short opening flare. The post-cycle restart idea tries to isolate that opening stimulation with a nondepot exposure, but its treatment evidence is one uncontrolled case.
| Intent | Exposure actually studied | Supporting evidence |
|---|---|---|
| Sustained suppression | Defined intramuscular depot products repeated on their labeled interval | Current labels, controlled prostate studies, and pediatric single-arm studies |
| Attempted restart after anabolic steroids | One 100 microgram triptorelin test; route and formulation missing from the indexed abstract | One case report with one month of reported follow-up |
The case exposure cannot be treated as a smaller Trelstar or Triptodur depot.
Trelstar label · prostate use, depots, flare, harms
Current US prescribing information
DailyMed, US National Library of Medicine, effective June 30, 2026
Trelstar is labeled for advanced prostate cancer as a gluteal intramuscular pamoate depot. The three strengths have different release characteristics and are not additive: 3.75 mg every 4 weeks, 11.25 mg every 12 weeks, or 22.5 mg every 24 weeks. Testosterone rises first, then usually reaches the label castration threshold within four weeks.
- The 3.75 mg formulation peaked on day 4 in healthy male volunteers; the 11.25 mg and 22.5 mg formulations peaked around days 2 to 3 in men with advanced prostate cancer.
- The label warns about tumor flare, metabolic changes, cardiovascular disease, convulsions, severe cutaneous reactions, and QT/QTc prolongation.
- No drug-drug interaction studies involving Trelstar have been conducted.
- Participants / model
- Men with advanced prostate cancer; limited pharmacokinetic work also included healthy male volunteers and adults with organ impairment
- Treatment
- Triptorelin pamoate sustained-release intramuscular depots at 3.75, 11.25, or 22.5 mg
- Follow-up
- Product-dependent release over 4, 12, or 24 weeks
- Study design
- FDA-regulated product label
This label does not cover post-cycle therapy, central precocious puberty, endometriosis, fibroids, or breast cancer. Its roughly three-hour terminal phase comes from intravenous bolus data and is not a depot dosing interval.
Read the original sourceTriptodur label · pediatric six-month depot
Current US prescribing information
DailyMed, US National Library of Medicine, revised September 2025
Triptodur is labeled for central precocious puberty in children age 2 years and older as 22.5 mg intramuscularly every 24 weeks. In its uncontrolled 44-child study, stimulated LH was at or below 5 IU/L in 41 of 44 children at month 6 and 43 of 44 at month 12; 95% had no increase in the bone-age to chronological-age ratio and 89% had stabilized sexual maturation at month 12.
- The study included 39 girls and 5 boys, all previously untreated with a GnRH agonist.
- The label calls for hormone monitoring beginning 1 to 2 months after initiation, height every 3 to 6 months, and periodic bone-age monitoring.
- The September 2025 label added severe cutaneous adverse reactions to warnings.
- Participants / model
- 44 children age 2 to 9 years with central precocious puberty; 39 girls and 5 boys
- Treatment
- Triptorelin pamoate 22.5 mg intramuscularly every 24 weeks
- Follow-up
- Two dosing intervals, 12 months
- Study design
- FDA-regulated product label drawing on a single-arm open-label trial
There was no placebo or active comparator. Hormonal suppression thresholds and a 12-month maturation measure do not by themselves establish adult height, fertility, or long-term reproductive outcomes.
Read the original sourcePirola case · one man, one 100 microgram test
Single-patient case report
Pirola I et al. Fertility and Sterility. 2010
A 34-year-old man with prolonged hypogonadotropic hypogonadism after chronic anabolic-steroid use received one 100 microgram triptorelin test. Within one month, serum testosterone was in the normal range and he reported normal energy and libido. There was no comparator, and the indexed abstract does not state the route, exact formulation, baseline values, concurrent treatment, or longer follow-up.
- Participants / model
- One 34-year-old man with anabolic-steroid-associated hypogonadotropic hypogonadism
- Treatment
- One 100 microgram triptorelin test; route and formulation not reported in the indexed abstract
- Follow-up
- One month reported follow-up
- Study design
- Case report
A single temporal observation cannot establish causality, reproducibility, a safe route, or a reusable post-cycle protocol. It is a different exposure from the approved sustained-release depots.
Read the original sourceHow do Trelstar, Triptodur and Decapeptyl differ?
Trelstar and Triptodur are US pamoate depots with different approved uses. UK Decapeptyl products use the acetate salt and have their own release schedules and indications. The post-cycle case report does not identify its formulation or route.
| Product or exposure | Studied or labeled use | Route and interval |
|---|---|---|
| Trelstar, US pamoate depot | Advanced prostate cancer | Intramuscular; 3.75 mg every 4 weeks, 11.25 mg every 12 weeks, or 22.5 mg every 24 weeks |
| Triptodur, US pamoate depot | Central precocious puberty from age 2 | Intramuscular; 22.5 mg every 24 weeks |
| Decapeptyl SR 3 mg, UK acetate depot | Product-specific prostate cancer, endometriosis, fibroid, and selected breast-cancer indications | Intramuscular; every 28 days, with indication-specific duration and co-treatment rules |
| Pirola case-report test | Attempted recovery from anabolic-steroid-associated hypogonadism | One 100 microgram test; route and formulation not stated in the indexed abstract |
These are label and study descriptions, not a cross-product dosing recommendation.
Trelstar label · prostate use, depots, flare, harms
Current US prescribing information
DailyMed, US National Library of Medicine, effective June 30, 2026
Trelstar is labeled for advanced prostate cancer as a gluteal intramuscular pamoate depot. The three strengths have different release characteristics and are not additive: 3.75 mg every 4 weeks, 11.25 mg every 12 weeks, or 22.5 mg every 24 weeks. Testosterone rises first, then usually reaches the label castration threshold within four weeks.
- The 3.75 mg formulation peaked on day 4 in healthy male volunteers; the 11.25 mg and 22.5 mg formulations peaked around days 2 to 3 in men with advanced prostate cancer.
- The label warns about tumor flare, metabolic changes, cardiovascular disease, convulsions, severe cutaneous reactions, and QT/QTc prolongation.
- No drug-drug interaction studies involving Trelstar have been conducted.
- Participants / model
- Men with advanced prostate cancer; limited pharmacokinetic work also included healthy male volunteers and adults with organ impairment
- Treatment
- Triptorelin pamoate sustained-release intramuscular depots at 3.75, 11.25, or 22.5 mg
- Follow-up
- Product-dependent release over 4, 12, or 24 weeks
- Study design
- FDA-regulated product label
This label does not cover post-cycle therapy, central precocious puberty, endometriosis, fibroids, or breast cancer. Its roughly three-hour terminal phase comes from intravenous bolus data and is not a depot dosing interval.
Read the original sourceTriptodur label · pediatric six-month depot
Current US prescribing information
DailyMed, US National Library of Medicine, revised September 2025
Triptodur is labeled for central precocious puberty in children age 2 years and older as 22.5 mg intramuscularly every 24 weeks. In its uncontrolled 44-child study, stimulated LH was at or below 5 IU/L in 41 of 44 children at month 6 and 43 of 44 at month 12; 95% had no increase in the bone-age to chronological-age ratio and 89% had stabilized sexual maturation at month 12.
- The study included 39 girls and 5 boys, all previously untreated with a GnRH agonist.
- The label calls for hormone monitoring beginning 1 to 2 months after initiation, height every 3 to 6 months, and periodic bone-age monitoring.
- The September 2025 label added severe cutaneous adverse reactions to warnings.
- Participants / model
- 44 children age 2 to 9 years with central precocious puberty; 39 girls and 5 boys
- Treatment
- Triptorelin pamoate 22.5 mg intramuscularly every 24 weeks
- Follow-up
- Two dosing intervals, 12 months
- Study design
- FDA-regulated product label drawing on a single-arm open-label trial
There was no placebo or active comparator. Hormonal suppression thresholds and a 12-month maturation measure do not by themselves establish adult height, fertility, or long-term reproductive outcomes.
Read the original sourceUK Decapeptyl label · broader indications, bone and QT risks
Current UK product information
Ipsen Ltd. electronic Medicines Compendium. Updated June 9, 2026
The UK 3 mg acetate sustained-release product has local indications for several prostate-cancer settings, endometriosis, uterine fibroids, and ovarian suppression with tamoxifen or an aromatase inhibitor in selected premenopausal high-risk early breast cancer. For endometriosis and fibroids, the SmPC limits treatment to six months because of bone-density loss and says estrogen-progestogen add-back can reduce bone loss and vasomotor symptoms in endometriosis.
- The product is one intramuscular injection every 28 days; other Decapeptyl strengths have their own release intervals and indication details.
- The SmPC says androgen deprivation can prolong QT and lists QT-prolonging medicines as combinations requiring careful benefit-risk evaluation.
- For aromatase-inhibitor use, the label requires confirmed and continuously monitored ovarian suppression and warns against interrupting triptorelin.
- Participants / model
- Adults in the product-specific UK prostate cancer, endometriosis, uterine fibroid, and selected breast cancer indications
- Treatment
- Decapeptyl SR 3 mg triptorelin acetate sustained-release intramuscular injection
- Follow-up
- Indication-specific; 28-day injections, with a six-month maximum for endometriosis and fibroids
- Study design
- UK regulated Summary of Product Characteristics
These indications apply to the UK 3 mg product. Other strengths and the US Trelstar and Triptodur products have separate labels.
Read the original sourcePirola case · one man, one 100 microgram test
Single-patient case report
Pirola I et al. Fertility and Sterility. 2010
A 34-year-old man with prolonged hypogonadotropic hypogonadism after chronic anabolic-steroid use received one 100 microgram triptorelin test. Within one month, serum testosterone was in the normal range and he reported normal energy and libido. There was no comparator, and the indexed abstract does not state the route, exact formulation, baseline values, concurrent treatment, or longer follow-up.
- Participants / model
- One 34-year-old man with anabolic-steroid-associated hypogonadotropic hypogonadism
- Treatment
- One 100 microgram triptorelin test; route and formulation not reported in the indexed abstract
- Follow-up
- One month reported follow-up
- Study design
- Case report
A single temporal observation cannot establish causality, reproducibility, a safe route, or a reusable post-cycle protocol. It is a different exposure from the approved sustained-release depots.
Read the original sourceWhy do hormone levels rise before falling?
Triptorelin initially stimulates pituitary GnRH receptors to release more LH and FSH. Continued exposure desensitizes that signaling, reducing testosterone or estrogen production. The labels describe suppression developing over about four weeks.
- Trelstar 3.75 mg: testosterone peaked on day 4 in healthy male volunteers and fell to low levels by week 4.
- Trelstar 11.25 and 22.5 mg: testosterone peaked around days 2 to 3 in men with advanced prostate cancer and fell to low levels around weeks 3 to 4.
- Triptodur 22.5 mg: the pediatric label describes an initial hormone surge and sustained suppression by about four weeks.
That opening flare is a known part of continuous-agonist pharmacology. It does not prove that an isolated exposure reliably restarts an axis after exogenous-androgen suppression.
Trelstar label · prostate use, depots, flare, harms
Current US prescribing information
DailyMed, US National Library of Medicine, effective June 30, 2026
Trelstar is labeled for advanced prostate cancer as a gluteal intramuscular pamoate depot. The three strengths have different release characteristics and are not additive: 3.75 mg every 4 weeks, 11.25 mg every 12 weeks, or 22.5 mg every 24 weeks. Testosterone rises first, then usually reaches the label castration threshold within four weeks.
- The 3.75 mg formulation peaked on day 4 in healthy male volunteers; the 11.25 mg and 22.5 mg formulations peaked around days 2 to 3 in men with advanced prostate cancer.
- The label warns about tumor flare, metabolic changes, cardiovascular disease, convulsions, severe cutaneous reactions, and QT/QTc prolongation.
- No drug-drug interaction studies involving Trelstar have been conducted.
- Participants / model
- Men with advanced prostate cancer; limited pharmacokinetic work also included healthy male volunteers and adults with organ impairment
- Treatment
- Triptorelin pamoate sustained-release intramuscular depots at 3.75, 11.25, or 22.5 mg
- Follow-up
- Product-dependent release over 4, 12, or 24 weeks
- Study design
- FDA-regulated product label
This label does not cover post-cycle therapy, central precocious puberty, endometriosis, fibroids, or breast cancer. Its roughly three-hour terminal phase comes from intravenous bolus data and is not a depot dosing interval.
Read the original sourceTriptodur label · pediatric six-month depot
Current US prescribing information
DailyMed, US National Library of Medicine, revised September 2025
Triptodur is labeled for central precocious puberty in children age 2 years and older as 22.5 mg intramuscularly every 24 weeks. In its uncontrolled 44-child study, stimulated LH was at or below 5 IU/L in 41 of 44 children at month 6 and 43 of 44 at month 12; 95% had no increase in the bone-age to chronological-age ratio and 89% had stabilized sexual maturation at month 12.
- The study included 39 girls and 5 boys, all previously untreated with a GnRH agonist.
- The label calls for hormone monitoring beginning 1 to 2 months after initiation, height every 3 to 6 months, and periodic bone-age monitoring.
- The September 2025 label added severe cutaneous adverse reactions to warnings.
- Participants / model
- 44 children age 2 to 9 years with central precocious puberty; 39 girls and 5 boys
- Treatment
- Triptorelin pamoate 22.5 mg intramuscularly every 24 weeks
- Follow-up
- Two dosing intervals, 12 months
- Study design
- FDA-regulated product label drawing on a single-arm open-label trial
There was no placebo or active comparator. Hormonal suppression thresholds and a 12-month maturation measure do not by themselves establish adult height, fertility, or long-term reproductive outcomes.
Read the original sourceWhat did the prostate-cancer trials find?
Depot triptorelin reliably suppresses testosterone in the studied cancer settings. The evidence is much firmer for biochemical suppression than for superiority on survival or relapse outcomes.
Monthly depot versus leuprolide
In 284 men with advanced prostate cancer, triptorelin was slower at day 29: 91.2% versus 99.3% reached testosterone at or below 50 ng/dL. By day 57 the rates were 97.7% and 97.1%, and cumulative maintenance through day 253 was 96.2% and 91.2%. The trial concluded maintenance was equivalent. A short secondary survival difference is not evidence that triptorelin prolongs life more than leuprolide.
Early treatment after prostatectomy in China and Russia
PRIORITI randomized 226 high-risk, node-negative men after surgery to triptorelin or surveillance. The primary biochemical-relapse analysis was not significant: first-quartile relapse-free time was 39.1 versus 30.0 months, P=0.16, and the hazard ratio was 0.65 with a 95% CI of 0.38 to 1.09, P=0.10. Chemical castration at month 9 was 93.9% in the triptorelin arm. The study therefore confirms suppression in this setting while leaving the relapse benefit unresolved.
Heyns trial · 284 men, testosterone suppression
Randomized active-controlled trial
Heyns CF et al. BJU International. 2003
Two hundred eighty-four men received triptorelin 3.75 mg or leuprolide 7.5 mg every 28 days for nine injections. At day 29, 91.2% versus 99.3% had testosterone at or below 50 ng/dL; at day 57, the rates were 97.7% and 97.1%. Mean maintenance was 98.8% versus 97.3%, and cumulative maintenance was 96.2% versus 91.2%; the maintenance results were equivalent.
- Participants / model
- 284 men with advanced prostate cancer; 140 assigned triptorelin and 144 assigned leuprolide
- Treatment
- Triptorelin pamoate 3.75 mg or leuprolide acetate 7.5 mg intramuscularly every 28 days
- Follow-up
- Nine injections over 253 days
- Study design
- Randomized active-controlled trial
The 97.0% versus 90.5% nine-month survival difference was a secondary finding in a short hormone-suppression trial. It does not establish a survival advantage over leuprolide.
Read the original sourcePRIORITI · 226 men, primary relapse result not significant
Phase 4 randomized open-label controlled trial
Matveev V et al. Asia-Pacific Journal of Clinical Oncology. 2024
At 18 centers in China and Russia, 226 men with high-risk node-negative prostate cancer after radical prostatectomy were randomized to nine months of triptorelin or active surveillance. The first-quartile time to biochemical relapse was 39.1 versus 30.0 months (P=0.16), and the relapse hazard ratio was 0.65 (95% CI 0.38 to 1.09; P=0.10). Neither primary analysis was significant. At month 9, 93.9% of evaluated triptorelin participants remained chemically castrated.
- The triptorelin arm received 11.25 mg intramuscularly at baseline and months 3 and 6; both groups were followed every three months for at least 36 months.
- There were no significant differences in event-free survival or overall survival, with too few events for useful survival conclusions.
- Ipsen sponsored the study and participated in design, analysis, interpretation, and manuscript review.
- Participants / model
- 226 men in China and Russia after radical prostatectomy, with high-risk prostate cancer and no lymph-node or distant metastases; 109 triptorelin and 117 surveillance
- Treatment
- Triptorelin 11.25 mg intramuscularly at baseline, month 3, and month 6 versus active surveillance
- Follow-up
- Nine months of treatment; visits every three months for at least 36 months
- Study design
- Prospective open-label randomized controlled phase 4 trial at nine centers in each country
- Funding
- Sponsored by Ipsen; sponsor involved in design, analysis, interpretation, and manuscript review
The trial supports biochemical suppression in this population. Its primary relapse endpoint did not establish a benefit over surveillance, and it was not a trial of metastatic disease, radiotherapy, or post-cycle recovery.
Read the original sourceHow strong is the evidence in central precocious puberty?
Depot triptorelin suppresses LH and slows pubertal progression in children with central precocious puberty. The studies below used different formulations and LH thresholds, so their suppression rates are not direct comparisons between products.
| Evidence | Population and comparator | Result |
|---|---|---|
| US Triptodur label | 44 previously untreated children age 2 to 9; single arm | Stimulated LH at or below 5 IU/L in 41/44 at month 6 and 43/44 at month 12 |
| Three-month pooled analysis | 153 children, 140 girls and 13 boys; no pooled untreated comparator | Stimulated LH at or below 3 IU/L in 87.6% at month 3 and 92.8% at month 6 |
| Chinese six-month filing | 66 previously untreated Chinese children; single arm | Stimulated LH at or below 5 IU/L in 66/66 at month 6; no public technical review report |
An LH threshold of 3 IU/L is stricter than 5 IU/L. The studies also enrolled different groups of children.
For Triptodur, the current label starts biochemical monitoring 1 to 2 months after initiation, repeats it as needed and with subsequent doses, measures height every 3 to 6 months, and follows bone age periodically. If suppression is inadequate, the label says a product with adjustable dosing may be needed.
Triptodur label · pediatric six-month depot
Current US prescribing information
DailyMed, US National Library of Medicine, revised September 2025
Triptodur is labeled for central precocious puberty in children age 2 years and older as 22.5 mg intramuscularly every 24 weeks. In its uncontrolled 44-child study, stimulated LH was at or below 5 IU/L in 41 of 44 children at month 6 and 43 of 44 at month 12; 95% had no increase in the bone-age to chronological-age ratio and 89% had stabilized sexual maturation at month 12.
- The study included 39 girls and 5 boys, all previously untreated with a GnRH agonist.
- The label calls for hormone monitoring beginning 1 to 2 months after initiation, height every 3 to 6 months, and periodic bone-age monitoring.
- The September 2025 label added severe cutaneous adverse reactions to warnings.
- Participants / model
- 44 children age 2 to 9 years with central precocious puberty; 39 girls and 5 boys
- Treatment
- Triptorelin pamoate 22.5 mg intramuscularly every 24 weeks
- Follow-up
- Two dosing intervals, 12 months
- Study design
- FDA-regulated product label drawing on a single-arm open-label trial
There was no placebo or active comparator. Hormonal suppression thresholds and a 12-month maturation measure do not by themselves establish adult height, fertility, or long-term reproductive outcomes.
Read the original sourceDurand analysis · 153 children, three-month depot
Pooled clinical-study analysis
Durand A et al. Hormone Research in Paediatrics. 2017
The analysis pooled 153 children, 140 girls and 13 boys, who received triptorelin 11.25 mg every three months. Using a stimulated LH threshold of 3 IU/L or lower, 87.6% were suppressed at month 3 and 92.8% at month 6. At month 3, estradiol was suppressed in 97.1% of girls and testosterone in 72.7% of boys, with a very wide 95% confidence interval for the small male subgroup.
- Participants / model
- 153 children with central precocious puberty; 140 girls and 13 boys
- Treatment
- Triptorelin 11.25 mg intramuscular prolonged-release formulation every three months
- Follow-up
- Six months
- Study design
- Pooled analysis of all available clinical studies of the formulation, without a pooled untreated comparator
This is a formulation-specific hormonal-suppression analysis. Its 3 IU/L LH threshold differs from the 5 IU/L threshold in the Triptodur and Chinese six-month-depot sources, so their percentages are not direct product rankings.
Read the original sourceChina filing · local 66-child single-arm result
Chinese-language official-hosted sponsor filing
National Healthcare Security Administration of China. 2025 public filing YPSW202500412
The public filing describes a China premarketing single-arm study of the 22.5 mg six-month formulation in 66 previously untreated Chinese children with central precocious puberty. At month 6, all 66 in the intention-to-treat population had stimulated LH at or below 5 IU/L. It names no concurrent comparator and supplies no public technical-review report.
- Participants / model
- 66 Chinese children with central precocious puberty who had not previously received a GnRH agonist
- Treatment
- Six-month triptorelin pamoate formulation; the filing lists 22.5 mg intramuscularly every six months for the marketed product
- Follow-up
- Primary result at month 6
- Study design
- Premarketing single-arm study summarized in a sponsor reimbursement filing
- Funding
- Filed by Ipsen (Tianjin) Pharmaceutical Trade Co., Ltd.
The 66/66 result is an official-hosted sponsor summary rather than an independent peer-reviewed report. The filing does not include a technical assessment report, full protocol, adverse-event table, or comparator result.
Read the original sourceWhat do we know about recovery after pediatric suppression ends?
Puberty usually resumes after treatment stops. A Russian follow-up tracked the timing of menstruation in 17 girls, but did not measure ovulation, pregnancy or adult fertility.
The Triptodur label says treatment is stopped at an age appropriate for normal puberty, based on clinician judgment. A Russian record review and online survey followed 17 girls whose treatment ended at age 12. Menarche occurred by 6 months in 4, during months 6 to 12 in 9, and during months 18 to 24 in 3. One participant had not menstruated at age 16 and was diagnosed with polycystic ovary syndrome.
That cohort had no untreated comparison, treatment length was not randomized, and it did not measure ovulation, pregnancy, or adult fertility.
Triptodur label · pediatric six-month depot
Current US prescribing information
DailyMed, US National Library of Medicine, revised September 2025
Triptodur is labeled for central precocious puberty in children age 2 years and older as 22.5 mg intramuscularly every 24 weeks. In its uncontrolled 44-child study, stimulated LH was at or below 5 IU/L in 41 of 44 children at month 6 and 43 of 44 at month 12; 95% had no increase in the bone-age to chronological-age ratio and 89% had stabilized sexual maturation at month 12.
- The study included 39 girls and 5 boys, all previously untreated with a GnRH agonist.
- The label calls for hormone monitoring beginning 1 to 2 months after initiation, height every 3 to 6 months, and periodic bone-age monitoring.
- The September 2025 label added severe cutaneous adverse reactions to warnings.
- Participants / model
- 44 children age 2 to 9 years with central precocious puberty; 39 girls and 5 boys
- Treatment
- Triptorelin pamoate 22.5 mg intramuscularly every 24 weeks
- Follow-up
- Two dosing intervals, 12 months
- Study design
- FDA-regulated product label drawing on a single-arm open-label trial
There was no placebo or active comparator. Hormonal suppression thresholds and a 12-month maturation measure do not by themselves establish adult height, fertility, or long-term reproductive outcomes.
Read the original sourceRussian cohort · 17 girls after treatment ended
Russian-language retrospective chart review and online survey
Tyrtova LV et al. Children's Medicine of the North-West. 2024;12(4):158-167
The authors reviewed records and surveyed 17 girls treated for central precocious puberty and followed after triptorelin ended at age 12. Menarche occurred by 6 months in 4 of 17, from 6 to 12 months in 9 of 17, and from 18 to 24 months in 3 of 17. One 16-year-old had not menstruated and was diagnosed with polycystic ovary syndrome. The study did not measure adult fertility.
- Participants / model
- 17 girls treated in Saint Petersburg, surveyed from age 12 years 9 months to 17 years 4 months after completing treatment
- Treatment
- Prior cyclic suppressive triptorelin under local clinical recommendations; individual formulation assignments were not fully reported
- Follow-up
- Prior treatment ranged from 1 year to 7 years 10 months; post-treatment timing was collected by record review and online survey
- Study design
- Retrospective medical-record analysis plus online patient survey, no untreated comparator
- Funding
- The authors report no external funding and no conflicts of interest
The cohort included 17 girls, treatment duration was not randomized, outcomes were partly self-reported, and there was no untreated group. It supports observed post-treatment timing, not a causal claim that longer treatment delays recovery or proof of later fertility.
Read the original sourceDoes triptorelin work for post-cycle therapy?
The evidence is one case report: a man’s testosterone, energy and libido improved within a month after a triptorelin test. Without a comparison group or longer follow-up, the report cannot establish that triptorelin caused recovery or that it would work reliably in other men.
- Known: one patient, one exposure, testosterone and symptom improvement at one month.
- Missing from the indexed abstract: route, formulation, exact baseline values, concurrent treatment, complete steroid exposure, and longer follow-up.
- Not established: causality, repeatability, fertility recovery, an optimal timing window, or a safe reusable protocol.
No controlled triptorelin recovery trial after anabolic-steroid exposure appeared in PubMed or ClinicalTrials.gov.
Pirola case · one man, one 100 microgram test
Single-patient case report
Pirola I et al. Fertility and Sterility. 2010
A 34-year-old man with prolonged hypogonadotropic hypogonadism after chronic anabolic-steroid use received one 100 microgram triptorelin test. Within one month, serum testosterone was in the normal range and he reported normal energy and libido. There was no comparator, and the indexed abstract does not state the route, exact formulation, baseline values, concurrent treatment, or longer follow-up.
- Participants / model
- One 34-year-old man with anabolic-steroid-associated hypogonadotropic hypogonadism
- Treatment
- One 100 microgram triptorelin test; route and formulation not reported in the indexed abstract
- Follow-up
- One month reported follow-up
- Study design
- Case report
A single temporal observation cannot establish causality, reproducibility, a safe route, or a reusable post-cycle protocol. It is a different exposure from the approved sustained-release depots.
Read the original sourcePost-cycle recovery evidence
Post-cycle recovery evidence
PubMed and ClinicalTrials.gov.
The cited records include diagnostic GnRH testing and standard hypogonadotropic-hypogonadism therapy, but no controlled post-anabolic-steroid “PCT” regimen matching the case report.
- Participants / model
- People with anabolic-steroid exposure or hypogonadotropic hypogonadism in the cited records
- Treatment
- Triptorelin proposed for recovery after anabolic-steroid exposure
Many cited adjacent records are diagnostic or disease-treatment studies rather than controlled post-cycle therapy.
Read the original sourceDoes a three-hour half-life describe the depots?
The roughly three-hour value describes a terminal phase after an intravenous bolus. Depot exposure depends on release and absorption from microspheres, so its clinical interval is weeks or months rather than one plasma half-life.
After intramuscular Trelstar, serum triptorelin peaks in about 1 to 3 hours, while the depot continues releasing drug over its labeled interval. Triptodur likewise has an initial burst followed by a maintenance-release phase. The intravenous terminal half-life cannot describe either depot’s release curve.
Trelstar label · prostate use, depots, flare, harms
Current US prescribing information
DailyMed, US National Library of Medicine, effective June 30, 2026
Trelstar is labeled for advanced prostate cancer as a gluteal intramuscular pamoate depot. The three strengths have different release characteristics and are not additive: 3.75 mg every 4 weeks, 11.25 mg every 12 weeks, or 22.5 mg every 24 weeks. Testosterone rises first, then usually reaches the label castration threshold within four weeks.
- The 3.75 mg formulation peaked on day 4 in healthy male volunteers; the 11.25 mg and 22.5 mg formulations peaked around days 2 to 3 in men with advanced prostate cancer.
- The label warns about tumor flare, metabolic changes, cardiovascular disease, convulsions, severe cutaneous reactions, and QT/QTc prolongation.
- No drug-drug interaction studies involving Trelstar have been conducted.
- Participants / model
- Men with advanced prostate cancer; limited pharmacokinetic work also included healthy male volunteers and adults with organ impairment
- Treatment
- Triptorelin pamoate sustained-release intramuscular depots at 3.75, 11.25, or 22.5 mg
- Follow-up
- Product-dependent release over 4, 12, or 24 weeks
- Study design
- FDA-regulated product label
This label does not cover post-cycle therapy, central precocious puberty, endometriosis, fibroids, or breast cancer. Its roughly three-hour terminal phase comes from intravenous bolus data and is not a depot dosing interval.
Read the original sourceTriptodur label · pediatric six-month depot
Current US prescribing information
DailyMed, US National Library of Medicine, revised September 2025
Triptodur is labeled for central precocious puberty in children age 2 years and older as 22.5 mg intramuscularly every 24 weeks. In its uncontrolled 44-child study, stimulated LH was at or below 5 IU/L in 41 of 44 children at month 6 and 43 of 44 at month 12; 95% had no increase in the bone-age to chronological-age ratio and 89% had stabilized sexual maturation at month 12.
- The study included 39 girls and 5 boys, all previously untreated with a GnRH agonist.
- The label calls for hormone monitoring beginning 1 to 2 months after initiation, height every 3 to 6 months, and periodic bone-age monitoring.
- The September 2025 label added severe cutaneous adverse reactions to warnings.
- Participants / model
- 44 children age 2 to 9 years with central precocious puberty; 39 girls and 5 boys
- Treatment
- Triptorelin pamoate 22.5 mg intramuscularly every 24 weeks
- Follow-up
- Two dosing intervals, 12 months
- Study design
- FDA-regulated product label drawing on a single-arm open-label trial
There was no placebo or active comparator. Hormonal suppression thresholds and a 12-month maturation measure do not by themselves establish adult height, fertility, or long-term reproductive outcomes.
Read the original sourceWhich risks matter during prostate-cancer treatment?
The initial testosterone rise can worsen tumor symptoms, including urinary obstruction or spinal-cord compression. Sustained androgen deprivation can cause hot flushes, sexual dysfunction and bone loss; the label also warns about cardiovascular, metabolic, seizure, allergic and severe skin risks.
- First weeks: worse bone pain, neuropathy, hematuria, urethral or bladder-outlet obstruction, and possible spinal-cord compression. Vertebral metastases and existing urinary obstruction require close attention.
- Sustained androgen deprivation: hot flushes, sexual dysfunction, testicular atrophy, loss of bone density, anemia, and changes in glucose and lipids.
- Higher-consequence warnings: cardiovascular disease, QT/QTc prolongation, convulsions, anaphylaxis or angioedema, and severe cutaneous reactions including SJS/TEN, DRESS, and AGEP.
Spontaneous adverse-event reports cannot establish how often a side effect occurs because the number of treated people is unknown. The linked product labels describe the risks and required monitoring.
Trelstar label · prostate use, depots, flare, harms
Current US prescribing information
DailyMed, US National Library of Medicine, effective June 30, 2026
Trelstar is labeled for advanced prostate cancer as a gluteal intramuscular pamoate depot. The three strengths have different release characteristics and are not additive: 3.75 mg every 4 weeks, 11.25 mg every 12 weeks, or 22.5 mg every 24 weeks. Testosterone rises first, then usually reaches the label castration threshold within four weeks.
- The 3.75 mg formulation peaked on day 4 in healthy male volunteers; the 11.25 mg and 22.5 mg formulations peaked around days 2 to 3 in men with advanced prostate cancer.
- The label warns about tumor flare, metabolic changes, cardiovascular disease, convulsions, severe cutaneous reactions, and QT/QTc prolongation.
- No drug-drug interaction studies involving Trelstar have been conducted.
- Participants / model
- Men with advanced prostate cancer; limited pharmacokinetic work also included healthy male volunteers and adults with organ impairment
- Treatment
- Triptorelin pamoate sustained-release intramuscular depots at 3.75, 11.25, or 22.5 mg
- Follow-up
- Product-dependent release over 4, 12, or 24 weeks
- Study design
- FDA-regulated product label
This label does not cover post-cycle therapy, central precocious puberty, endometriosis, fibroids, or breast cancer. Its roughly three-hour terminal phase comes from intravenous bolus data and is not a depot dosing interval.
Read the original sourceUK Decapeptyl label · broader indications, bone and QT risks
Current UK product information
Ipsen Ltd. electronic Medicines Compendium. Updated June 9, 2026
The UK 3 mg acetate sustained-release product has local indications for several prostate-cancer settings, endometriosis, uterine fibroids, and ovarian suppression with tamoxifen or an aromatase inhibitor in selected premenopausal high-risk early breast cancer. For endometriosis and fibroids, the SmPC limits treatment to six months because of bone-density loss and says estrogen-progestogen add-back can reduce bone loss and vasomotor symptoms in endometriosis.
- The product is one intramuscular injection every 28 days; other Decapeptyl strengths have their own release intervals and indication details.
- The SmPC says androgen deprivation can prolong QT and lists QT-prolonging medicines as combinations requiring careful benefit-risk evaluation.
- For aromatase-inhibitor use, the label requires confirmed and continuously monitored ovarian suppression and warns against interrupting triptorelin.
- Participants / model
- Adults in the product-specific UK prostate cancer, endometriosis, uterine fibroid, and selected breast cancer indications
- Treatment
- Decapeptyl SR 3 mg triptorelin acetate sustained-release intramuscular injection
- Follow-up
- Indication-specific; 28-day injections, with a six-month maximum for endometriosis and fibroids
- Study design
- UK regulated Summary of Product Characteristics
These indications apply to the UK 3 mg product. Other strengths and the US Trelstar and Triptodur products have separate labels.
Read the original sourceWhich risks and monitoring questions matter in children?
The opening hormone surge can briefly intensify puberty signs, including vaginal bleeding. Persistent signs, inadequate suppression, psychiatric change, seizure, severe rash, or symptoms of raised intracranial pressure require product-specific evaluation.
In the 44-child Triptodur trial, the adverse reactions reported in at least two children included injection-site reactions, vaginal bleeding, hot flush, headache, cough, and several common infections. Without a control arm, those counts cannot separate drug effects from background childhood events.
- Psychiatric warning: new or worsening crying, irritability, impatience, anger, aggression, or depression has been reported with the class.
- Neurologic warning: convulsions can occur with or without known risk factors. Idiopathic intracranial hypertension can present with headache, vision change, eye pain, tinnitus, dizziness, or nausea.
- Skin warning: fever or flu-like symptoms with mucosal lesions, a progressive rash, or swollen lymph nodes can signal a severe cutaneous reaction.
Triptodur label · pediatric six-month depot
Current US prescribing information
DailyMed, US National Library of Medicine, revised September 2025
Triptodur is labeled for central precocious puberty in children age 2 years and older as 22.5 mg intramuscularly every 24 weeks. In its uncontrolled 44-child study, stimulated LH was at or below 5 IU/L in 41 of 44 children at month 6 and 43 of 44 at month 12; 95% had no increase in the bone-age to chronological-age ratio and 89% had stabilized sexual maturation at month 12.
- The study included 39 girls and 5 boys, all previously untreated with a GnRH agonist.
- The label calls for hormone monitoring beginning 1 to 2 months after initiation, height every 3 to 6 months, and periodic bone-age monitoring.
- The September 2025 label added severe cutaneous adverse reactions to warnings.
- Participants / model
- 44 children age 2 to 9 years with central precocious puberty; 39 girls and 5 boys
- Treatment
- Triptorelin pamoate 22.5 mg intramuscularly every 24 weeks
- Follow-up
- Two dosing intervals, 12 months
- Study design
- FDA-regulated product label drawing on a single-arm open-label trial
There was no placebo or active comparator. Hormonal suppression thresholds and a 12-month maturation measure do not by themselves establish adult height, fertility, or long-term reproductive outcomes.
Read the original sourceIs triptorelin used for endometriosis, fibroids or breast cancer?
The UK Decapeptyl SR 3 mg label includes these uses. The US Trelstar and Triptodur labels do not.
Endometriosis and uterine fibroids
The UK product is limited to six months because of bone-density loss. The SmPC says estrogen-progestogen add-back can reduce bone loss and vasomotor symptoms in endometriosis. Bleeding after the first month warrants evaluation, and fibroid size is monitored during treatment.
Selected premenopausal early breast cancer
In this regimen, triptorelin provides ovarian suppression paired with tamoxifen or an aromatase inhibitor. Premenopausal status must be confirmed after chemotherapy. Before an aromatase inhibitor, suppression is established first and then monitored with serial FSH and estradiol; interrupting triptorelin can allow ovarian estrogen production to rebound.
UK Decapeptyl label · broader indications, bone and QT risks
Current UK product information
Ipsen Ltd. electronic Medicines Compendium. Updated June 9, 2026
The UK 3 mg acetate sustained-release product has local indications for several prostate-cancer settings, endometriosis, uterine fibroids, and ovarian suppression with tamoxifen or an aromatase inhibitor in selected premenopausal high-risk early breast cancer. For endometriosis and fibroids, the SmPC limits treatment to six months because of bone-density loss and says estrogen-progestogen add-back can reduce bone loss and vasomotor symptoms in endometriosis.
- The product is one intramuscular injection every 28 days; other Decapeptyl strengths have their own release intervals and indication details.
- The SmPC says androgen deprivation can prolong QT and lists QT-prolonging medicines as combinations requiring careful benefit-risk evaluation.
- For aromatase-inhibitor use, the label requires confirmed and continuously monitored ovarian suppression and warns against interrupting triptorelin.
- Participants / model
- Adults in the product-specific UK prostate cancer, endometriosis, uterine fibroid, and selected breast cancer indications
- Treatment
- Decapeptyl SR 3 mg triptorelin acetate sustained-release intramuscular injection
- Follow-up
- Indication-specific; 28-day injections, with a six-month maximum for endometriosis and fibroids
- Study design
- UK regulated Summary of Product Characteristics
These indications apply to the UK 3 mg product. Other strengths and the US Trelstar and Triptodur products have separate labels.
Read the original sourceWhich medicines interact, and what about pregnancy?
Trelstar has not undergone drug-interaction studies. Its label and the UK Decapeptyl label identify precautions involving QT-prolonging medicines, pituitary signaling and pregnancy.
- QT risk: androgen-deprivation products can prolong QT. The UK SmPC calls out class IA and III antiarrhythmics, methadone, moxifloxacin, antipsychotics, and other QT-prolonging medicines for careful benefit-risk review.
- Pituitary signaling: Trelstar advises against hyperprolactinemic drugs as a precaution because hyperprolactinemia can reduce pituitary GnRH receptors.
- Pregnancy: Trelstar warns of fetal harm from the expected hormonal mechanism; the UK Decapeptyl product is contraindicated during pregnancy and lactation.
- Breast-cancer combinations: aromatase-inhibitor use depends on uninterrupted, confirmed ovarian suppression, because estrogen production can resume if suppression lapses.
Trelstar label · prostate use, depots, flare, harms
Current US prescribing information
DailyMed, US National Library of Medicine, effective June 30, 2026
Trelstar is labeled for advanced prostate cancer as a gluteal intramuscular pamoate depot. The three strengths have different release characteristics and are not additive: 3.75 mg every 4 weeks, 11.25 mg every 12 weeks, or 22.5 mg every 24 weeks. Testosterone rises first, then usually reaches the label castration threshold within four weeks.
- The 3.75 mg formulation peaked on day 4 in healthy male volunteers; the 11.25 mg and 22.5 mg formulations peaked around days 2 to 3 in men with advanced prostate cancer.
- The label warns about tumor flare, metabolic changes, cardiovascular disease, convulsions, severe cutaneous reactions, and QT/QTc prolongation.
- No drug-drug interaction studies involving Trelstar have been conducted.
- Participants / model
- Men with advanced prostate cancer; limited pharmacokinetic work also included healthy male volunteers and adults with organ impairment
- Treatment
- Triptorelin pamoate sustained-release intramuscular depots at 3.75, 11.25, or 22.5 mg
- Follow-up
- Product-dependent release over 4, 12, or 24 weeks
- Study design
- FDA-regulated product label
This label does not cover post-cycle therapy, central precocious puberty, endometriosis, fibroids, or breast cancer. Its roughly three-hour terminal phase comes from intravenous bolus data and is not a depot dosing interval.
Read the original sourceUK Decapeptyl label · broader indications, bone and QT risks
Current UK product information
Ipsen Ltd. electronic Medicines Compendium. Updated June 9, 2026
The UK 3 mg acetate sustained-release product has local indications for several prostate-cancer settings, endometriosis, uterine fibroids, and ovarian suppression with tamoxifen or an aromatase inhibitor in selected premenopausal high-risk early breast cancer. For endometriosis and fibroids, the SmPC limits treatment to six months because of bone-density loss and says estrogen-progestogen add-back can reduce bone loss and vasomotor symptoms in endometriosis.
- The product is one intramuscular injection every 28 days; other Decapeptyl strengths have their own release intervals and indication details.
- The SmPC says androgen deprivation can prolong QT and lists QT-prolonging medicines as combinations requiring careful benefit-risk evaluation.
- For aromatase-inhibitor use, the label requires confirmed and continuously monitored ovarian suppression and warns against interrupting triptorelin.
- Participants / model
- Adults in the product-specific UK prostate cancer, endometriosis, uterine fibroid, and selected breast cancer indications
- Treatment
- Decapeptyl SR 3 mg triptorelin acetate sustained-release intramuscular injection
- Follow-up
- Indication-specific; 28-day injections, with a six-month maximum for endometriosis and fibroids
- Study design
- UK regulated Summary of Product Characteristics
These indications apply to the UK 3 mg product. Other strengths and the US Trelstar and Triptodur products have separate labels.
Read the original sourceWhy C tier?
C tier reflects the evidence for post-cycle recovery: one uncontrolled case and no controlled recovery trial in the public record. Approved depot treatments for prostate cancer and central precocious puberty have much stronger evidence for sustained hormone suppression.
- Established: product-specific sustained suppression, current labels, and direct human hormonal outcomes.
- Indication-dependent: disease outcomes, treatment duration, monitoring, and benefit-risk tradeoffs differ between prostate cancer, CPP, endometriosis, fibroids, and breast cancer.
- Unestablished: a reproducible nondepot restart protocol after anabolic steroids, including route, formulation, timing, repeat exposure, fertility outcome, and safety.
Trelstar label · prostate use, depots, flare, harms
Current US prescribing information
DailyMed, US National Library of Medicine, effective June 30, 2026
Trelstar is labeled for advanced prostate cancer as a gluteal intramuscular pamoate depot. The three strengths have different release characteristics and are not additive: 3.75 mg every 4 weeks, 11.25 mg every 12 weeks, or 22.5 mg every 24 weeks. Testosterone rises first, then usually reaches the label castration threshold within four weeks.
- The 3.75 mg formulation peaked on day 4 in healthy male volunteers; the 11.25 mg and 22.5 mg formulations peaked around days 2 to 3 in men with advanced prostate cancer.
- The label warns about tumor flare, metabolic changes, cardiovascular disease, convulsions, severe cutaneous reactions, and QT/QTc prolongation.
- No drug-drug interaction studies involving Trelstar have been conducted.
- Participants / model
- Men with advanced prostate cancer; limited pharmacokinetic work also included healthy male volunteers and adults with organ impairment
- Treatment
- Triptorelin pamoate sustained-release intramuscular depots at 3.75, 11.25, or 22.5 mg
- Follow-up
- Product-dependent release over 4, 12, or 24 weeks
- Study design
- FDA-regulated product label
This label does not cover post-cycle therapy, central precocious puberty, endometriosis, fibroids, or breast cancer. Its roughly three-hour terminal phase comes from intravenous bolus data and is not a depot dosing interval.
Read the original sourceTriptodur label · pediatric six-month depot
Current US prescribing information
DailyMed, US National Library of Medicine, revised September 2025
Triptodur is labeled for central precocious puberty in children age 2 years and older as 22.5 mg intramuscularly every 24 weeks. In its uncontrolled 44-child study, stimulated LH was at or below 5 IU/L in 41 of 44 children at month 6 and 43 of 44 at month 12; 95% had no increase in the bone-age to chronological-age ratio and 89% had stabilized sexual maturation at month 12.
- The study included 39 girls and 5 boys, all previously untreated with a GnRH agonist.
- The label calls for hormone monitoring beginning 1 to 2 months after initiation, height every 3 to 6 months, and periodic bone-age monitoring.
- The September 2025 label added severe cutaneous adverse reactions to warnings.
- Participants / model
- 44 children age 2 to 9 years with central precocious puberty; 39 girls and 5 boys
- Treatment
- Triptorelin pamoate 22.5 mg intramuscularly every 24 weeks
- Follow-up
- Two dosing intervals, 12 months
- Study design
- FDA-regulated product label drawing on a single-arm open-label trial
There was no placebo or active comparator. Hormonal suppression thresholds and a 12-month maturation measure do not by themselves establish adult height, fertility, or long-term reproductive outcomes.
Read the original sourceHeyns trial · 284 men, testosterone suppression
Randomized active-controlled trial
Heyns CF et al. BJU International. 2003
Two hundred eighty-four men received triptorelin 3.75 mg or leuprolide 7.5 mg every 28 days for nine injections. At day 29, 91.2% versus 99.3% had testosterone at or below 50 ng/dL; at day 57, the rates were 97.7% and 97.1%. Mean maintenance was 98.8% versus 97.3%, and cumulative maintenance was 96.2% versus 91.2%; the maintenance results were equivalent.
- Participants / model
- 284 men with advanced prostate cancer; 140 assigned triptorelin and 144 assigned leuprolide
- Treatment
- Triptorelin pamoate 3.75 mg or leuprolide acetate 7.5 mg intramuscularly every 28 days
- Follow-up
- Nine injections over 253 days
- Study design
- Randomized active-controlled trial
The 97.0% versus 90.5% nine-month survival difference was a secondary finding in a short hormone-suppression trial. It does not establish a survival advantage over leuprolide.
Read the original sourcePirola case · one man, one 100 microgram test
Single-patient case report
Pirola I et al. Fertility and Sterility. 2010
A 34-year-old man with prolonged hypogonadotropic hypogonadism after chronic anabolic-steroid use received one 100 microgram triptorelin test. Within one month, serum testosterone was in the normal range and he reported normal energy and libido. There was no comparator, and the indexed abstract does not state the route, exact formulation, baseline values, concurrent treatment, or longer follow-up.
- Participants / model
- One 34-year-old man with anabolic-steroid-associated hypogonadotropic hypogonadism
- Treatment
- One 100 microgram triptorelin test; route and formulation not reported in the indexed abstract
- Follow-up
- One month reported follow-up
- Study design
- Case report
A single temporal observation cannot establish causality, reproducibility, a safe route, or a reusable post-cycle protocol. It is a different exposure from the approved sustained-release depots.
Read the original sourcePost-cycle recovery evidence
Post-cycle recovery evidence
PubMed and ClinicalTrials.gov.
The cited records include diagnostic GnRH testing and standard hypogonadotropic-hypogonadism therapy, but no controlled post-anabolic-steroid “PCT” regimen matching the case report.
- Participants / model
- People with anabolic-steroid exposure or hypogonadotropic hypogonadism in the cited records
- Treatment
- Triptorelin proposed for recovery after anabolic-steroid exposure
Many cited adjacent records are diagnostic or disease-treatment studies rather than controlled post-cycle therapy.
Read the original sourceStudies and sources
Trelstar label · prostate use, depots, flare, harms
Current US prescribing information
DailyMed, US National Library of Medicine, effective June 30, 2026
Trelstar is labeled for advanced prostate cancer as a gluteal intramuscular pamoate depot. The three strengths have different release characteristics and are not additive: 3.75 mg every 4 weeks, 11.25 mg every 12 weeks, or 22.5 mg every 24 weeks. Testosterone rises first, then usually reaches the label castration threshold within four weeks.
- The 3.75 mg formulation peaked on day 4 in healthy male volunteers; the 11.25 mg and 22.5 mg formulations peaked around days 2 to 3 in men with advanced prostate cancer.
- The label warns about tumor flare, metabolic changes, cardiovascular disease, convulsions, severe cutaneous reactions, and QT/QTc prolongation.
- No drug-drug interaction studies involving Trelstar have been conducted.
- Participants / model
- Men with advanced prostate cancer; limited pharmacokinetic work also included healthy male volunteers and adults with organ impairment
- Treatment
- Triptorelin pamoate sustained-release intramuscular depots at 3.75, 11.25, or 22.5 mg
- Follow-up
- Product-dependent release over 4, 12, or 24 weeks
- Study design
- FDA-regulated product label
This label does not cover post-cycle therapy, central precocious puberty, endometriosis, fibroids, or breast cancer. Its roughly three-hour terminal phase comes from intravenous bolus data and is not a depot dosing interval.
Read the original sourceTriptodur label · pediatric six-month depot
Current US prescribing information
DailyMed, US National Library of Medicine, revised September 2025
Triptodur is labeled for central precocious puberty in children age 2 years and older as 22.5 mg intramuscularly every 24 weeks. In its uncontrolled 44-child study, stimulated LH was at or below 5 IU/L in 41 of 44 children at month 6 and 43 of 44 at month 12; 95% had no increase in the bone-age to chronological-age ratio and 89% had stabilized sexual maturation at month 12.
- The study included 39 girls and 5 boys, all previously untreated with a GnRH agonist.
- The label calls for hormone monitoring beginning 1 to 2 months after initiation, height every 3 to 6 months, and periodic bone-age monitoring.
- The September 2025 label added severe cutaneous adverse reactions to warnings.
- Participants / model
- 44 children age 2 to 9 years with central precocious puberty; 39 girls and 5 boys
- Treatment
- Triptorelin pamoate 22.5 mg intramuscularly every 24 weeks
- Follow-up
- Two dosing intervals, 12 months
- Study design
- FDA-regulated product label drawing on a single-arm open-label trial
There was no placebo or active comparator. Hormonal suppression thresholds and a 12-month maturation measure do not by themselves establish adult height, fertility, or long-term reproductive outcomes.
Read the original sourceUK Decapeptyl label · broader indications, bone and QT risks
Current UK product information
Ipsen Ltd. electronic Medicines Compendium. Updated June 9, 2026
The UK 3 mg acetate sustained-release product has local indications for several prostate-cancer settings, endometriosis, uterine fibroids, and ovarian suppression with tamoxifen or an aromatase inhibitor in selected premenopausal high-risk early breast cancer. For endometriosis and fibroids, the SmPC limits treatment to six months because of bone-density loss and says estrogen-progestogen add-back can reduce bone loss and vasomotor symptoms in endometriosis.
- The product is one intramuscular injection every 28 days; other Decapeptyl strengths have their own release intervals and indication details.
- The SmPC says androgen deprivation can prolong QT and lists QT-prolonging medicines as combinations requiring careful benefit-risk evaluation.
- For aromatase-inhibitor use, the label requires confirmed and continuously monitored ovarian suppression and warns against interrupting triptorelin.
- Participants / model
- Adults in the product-specific UK prostate cancer, endometriosis, uterine fibroid, and selected breast cancer indications
- Treatment
- Decapeptyl SR 3 mg triptorelin acetate sustained-release intramuscular injection
- Follow-up
- Indication-specific; 28-day injections, with a six-month maximum for endometriosis and fibroids
- Study design
- UK regulated Summary of Product Characteristics
These indications apply to the UK 3 mg product. Other strengths and the US Trelstar and Triptodur products have separate labels.
Read the original sourceHeyns trial · 284 men, testosterone suppression
Randomized active-controlled trial
Heyns CF et al. BJU International. 2003
Two hundred eighty-four men received triptorelin 3.75 mg or leuprolide 7.5 mg every 28 days for nine injections. At day 29, 91.2% versus 99.3% had testosterone at or below 50 ng/dL; at day 57, the rates were 97.7% and 97.1%. Mean maintenance was 98.8% versus 97.3%, and cumulative maintenance was 96.2% versus 91.2%; the maintenance results were equivalent.
- Participants / model
- 284 men with advanced prostate cancer; 140 assigned triptorelin and 144 assigned leuprolide
- Treatment
- Triptorelin pamoate 3.75 mg or leuprolide acetate 7.5 mg intramuscularly every 28 days
- Follow-up
- Nine injections over 253 days
- Study design
- Randomized active-controlled trial
The 97.0% versus 90.5% nine-month survival difference was a secondary finding in a short hormone-suppression trial. It does not establish a survival advantage over leuprolide.
Read the original sourcePRIORITI · 226 men, primary relapse result not significant
Phase 4 randomized open-label controlled trial
Matveev V et al. Asia-Pacific Journal of Clinical Oncology. 2024
At 18 centers in China and Russia, 226 men with high-risk node-negative prostate cancer after radical prostatectomy were randomized to nine months of triptorelin or active surveillance. The first-quartile time to biochemical relapse was 39.1 versus 30.0 months (P=0.16), and the relapse hazard ratio was 0.65 (95% CI 0.38 to 1.09; P=0.10). Neither primary analysis was significant. At month 9, 93.9% of evaluated triptorelin participants remained chemically castrated.
- The triptorelin arm received 11.25 mg intramuscularly at baseline and months 3 and 6; both groups were followed every three months for at least 36 months.
- There were no significant differences in event-free survival or overall survival, with too few events for useful survival conclusions.
- Ipsen sponsored the study and participated in design, analysis, interpretation, and manuscript review.
- Participants / model
- 226 men in China and Russia after radical prostatectomy, with high-risk prostate cancer and no lymph-node or distant metastases; 109 triptorelin and 117 surveillance
- Treatment
- Triptorelin 11.25 mg intramuscularly at baseline, month 3, and month 6 versus active surveillance
- Follow-up
- Nine months of treatment; visits every three months for at least 36 months
- Study design
- Prospective open-label randomized controlled phase 4 trial at nine centers in each country
- Funding
- Sponsored by Ipsen; sponsor involved in design, analysis, interpretation, and manuscript review
The trial supports biochemical suppression in this population. Its primary relapse endpoint did not establish a benefit over surveillance, and it was not a trial of metastatic disease, radiotherapy, or post-cycle recovery.
Read the original sourceDurand analysis · 153 children, three-month depot
Pooled clinical-study analysis
Durand A et al. Hormone Research in Paediatrics. 2017
The analysis pooled 153 children, 140 girls and 13 boys, who received triptorelin 11.25 mg every three months. Using a stimulated LH threshold of 3 IU/L or lower, 87.6% were suppressed at month 3 and 92.8% at month 6. At month 3, estradiol was suppressed in 97.1% of girls and testosterone in 72.7% of boys, with a very wide 95% confidence interval for the small male subgroup.
- Participants / model
- 153 children with central precocious puberty; 140 girls and 13 boys
- Treatment
- Triptorelin 11.25 mg intramuscular prolonged-release formulation every three months
- Follow-up
- Six months
- Study design
- Pooled analysis of all available clinical studies of the formulation, without a pooled untreated comparator
This is a formulation-specific hormonal-suppression analysis. Its 3 IU/L LH threshold differs from the 5 IU/L threshold in the Triptodur and Chinese six-month-depot sources, so their percentages are not direct product rankings.
Read the original sourceChina filing · local 66-child single-arm result
Chinese-language official-hosted sponsor filing
National Healthcare Security Administration of China. 2025 public filing YPSW202500412
The public filing describes a China premarketing single-arm study of the 22.5 mg six-month formulation in 66 previously untreated Chinese children with central precocious puberty. At month 6, all 66 in the intention-to-treat population had stimulated LH at or below 5 IU/L. It names no concurrent comparator and supplies no public technical-review report.
- Participants / model
- 66 Chinese children with central precocious puberty who had not previously received a GnRH agonist
- Treatment
- Six-month triptorelin pamoate formulation; the filing lists 22.5 mg intramuscularly every six months for the marketed product
- Follow-up
- Primary result at month 6
- Study design
- Premarketing single-arm study summarized in a sponsor reimbursement filing
- Funding
- Filed by Ipsen (Tianjin) Pharmaceutical Trade Co., Ltd.
The 66/66 result is an official-hosted sponsor summary rather than an independent peer-reviewed report. The filing does not include a technical assessment report, full protocol, adverse-event table, or comparator result.
Read the original sourceRussian cohort · 17 girls after treatment ended
Russian-language retrospective chart review and online survey
Tyrtova LV et al. Children's Medicine of the North-West. 2024;12(4):158-167
The authors reviewed records and surveyed 17 girls treated for central precocious puberty and followed after triptorelin ended at age 12. Menarche occurred by 6 months in 4 of 17, from 6 to 12 months in 9 of 17, and from 18 to 24 months in 3 of 17. One 16-year-old had not menstruated and was diagnosed with polycystic ovary syndrome. The study did not measure adult fertility.
- Participants / model
- 17 girls treated in Saint Petersburg, surveyed from age 12 years 9 months to 17 years 4 months after completing treatment
- Treatment
- Prior cyclic suppressive triptorelin under local clinical recommendations; individual formulation assignments were not fully reported
- Follow-up
- Prior treatment ranged from 1 year to 7 years 10 months; post-treatment timing was collected by record review and online survey
- Study design
- Retrospective medical-record analysis plus online patient survey, no untreated comparator
- Funding
- The authors report no external funding and no conflicts of interest
The cohort included 17 girls, treatment duration was not randomized, outcomes were partly self-reported, and there was no untreated group. It supports observed post-treatment timing, not a causal claim that longer treatment delays recovery or proof of later fertility.
Read the original sourcePirola case · one man, one 100 microgram test
Single-patient case report
Pirola I et al. Fertility and Sterility. 2010
A 34-year-old man with prolonged hypogonadotropic hypogonadism after chronic anabolic-steroid use received one 100 microgram triptorelin test. Within one month, serum testosterone was in the normal range and he reported normal energy and libido. There was no comparator, and the indexed abstract does not state the route, exact formulation, baseline values, concurrent treatment, or longer follow-up.
- Participants / model
- One 34-year-old man with anabolic-steroid-associated hypogonadotropic hypogonadism
- Treatment
- One 100 microgram triptorelin test; route and formulation not reported in the indexed abstract
- Follow-up
- One month reported follow-up
- Study design
- Case report
A single temporal observation cannot establish causality, reproducibility, a safe route, or a reusable post-cycle protocol. It is a different exposure from the approved sustained-release depots.
Read the original sourcePost-cycle recovery evidence
Post-cycle recovery evidence
PubMed and ClinicalTrials.gov.
The cited records include diagnostic GnRH testing and standard hypogonadotropic-hypogonadism therapy, but no controlled post-anabolic-steroid “PCT” regimen matching the case report.
- Participants / model
- People with anabolic-steroid exposure or hypogonadotropic hypogonadism in the cited records
- Treatment
- Triptorelin proposed for recovery after anabolic-steroid exposure
Many cited adjacent records are diagnostic or disease-treatment studies rather than controlled post-cycle therapy.
Read the original sourceWhy is triptorelin in C tier?
C tier reflects the evidence for post-cycle recovery: one uncontrolled case and no controlled recovery trial in the public record. Approved depot treatments for prostate cancer and central precocious puberty have much stronger evidence for sustained hormone suppression.