Stanozolol
updated
Stanozolol, the anabolic-androgenic steroid once sold as Winstrol, has had its US approvals for human use withdrawn. People seek it for strength and a harder, drier look. In a controlled crossover of 11 male weightlifters, oral stanozolol cut HDL cholesterol 33% and raised LDL 29%, and two weeks of it lowered testosterone 55% in nine healthy men, while small controlled studies showed no predictable strength gain and none rated appearance. Graded B for direct human studies and well-measured lipid, hormone and liver harms, including severe liver injury after injected use.
Anabolic-androgenic steroid
- Winstrol
- Oral and injectable preparations
What is Winstrol?
Winstrol is a historical brand of stanozolol, an anabolic-androgenic steroid used in oral and injectable preparations.
The old US tablet approval, medical studies in other countries and an underground injectable product are separate records. A shared ingredient name does not establish current approval or product quality.
source: FDA · Winstrol withdrawal, Federal Register, July 21, 2010.
source: FDA · Winsteroid withdrawal, Federal Register, September 23, 2024.
source: China · aplastic-anemia study, Li HM et al. Chinese Journal of Hematology, 2022;43:157–160.
Does stanozolol improve strength or create a dry look?
The small controlled human studies do not establish a predictable strength gain or cosmetic result. Its effects on cholesterol and hormones are better measured.
A three-week study in 21 men doing endurance training found no significant advantage over control for strength or endurance. An older rehabilitation trial found increased activity but no anabolic effect. Neither measured visual hardness.
source: Endurance training · placebo comparison, Medicine and science in sports. PMID 798110.
source: Older adults · activity and body composition, Rheumatology and rehabilitation. PMID 139671.
Did the COPD study show muscle gain?
It found weight and lean-mass gains in undernourished men. But participants also received an initial testosterone injection and rehabilitation, and walking or maximal exercise performance did not improve. It cannot predict the result of stanozolol alone in a trained person.
source: COPD · combination trial, Chest. PMID 9674442.
What are the clearest human safety findings?
Oral stanozolol can cause large adverse cholesterol changes and suppress testosterone. Severe liver injury has also been reported after injected use.
| Cholesterol measure | Oral stanozolol | Injectable testosterone comparator |
|---|---|---|
| HDL | −33% | −9% |
| LDL | +29% | −16% |
Different drugs and routes. These results do not compare oral with injected stanozolol.
source: Oral stanozolol · HDL and LDL, JAMA. PMID 2915439.
Is injectable stanozolol safer for the liver?
Injection does not remove the risk. A published injected-use case developed severe cholestasis. The 18-patient liver-injury series also found pronounced jaundice and itching with relatively modest enzyme changes. Neither study can calculate which route is safer.
source: Injected stanozolol · severe cholestasis, Clinical and experimental hepatology. PMID 28856252.
source: Stanozolol · liver-injury registry, Journal of clinical and experimental hepatology. PMID 40040852.
What did long-term medical use show?
A follow-up of 21 people who had continued stanozolol for hereditary angioedema for 20 to 40 years found treatment-related symptoms in 10, reduced HDL in five and elevated triglycerides in two. It reported no persistent liver-enzyme abnormalities. This small group of long-term continuers had no untreated comparator, so it cannot establish a general long-term event rate or the safety of performance use.
source: Hereditary angioedema · long-term follow-up, The Journal of allergy and clinical immunology. PMID 17765757.
What symptoms should not be ignored?
Yellow skin or eyes, dark urine and severe itching can signal cholestatic injury even if ALT is not dramatically raised. They require prompt medical assessment. Acne, androgenic effects, mood changes and reproductive suppression are additional class-level concerns.
source: Stanozolol · liver-injury registry
source: FDA · steroid-product risks, US FDA, 2017.
Can it lower natural testosterone?
Yes. In nine healthy men, two weeks of oral stanozolol lowered measured testosterone by 55%, with reductions in LH and SHBG.
Those changes reversed after the study ended. That does not establish recovery after longer use, a mixed-drug regimen or effects on sperm production. A fall in SHBG is not proof of better sexual function or safer hormone exposure.
source: Hormone suppression · healthy volunteers, Clinical endocrinology. PMID 6430603.
source: SHBG · androgen-response study, The Journal of clinical endocrinology and metabolism. PMID 2723028.
source: FDA · steroid-product risks
Why is stanozolol studied in aplastic anemia in China?
Androgens have been used to support blood-cell production in bone-marrow failure. Chinese studies address that medical question, not muscle gain.
A 2022 Chinese-language retrospective study compared cyclosporine plus stanozolol, cyclosporine plus danazol, and cyclosporine alone. Six-month response was 65.0%, 42.9% and 40.0%; the groups were small and not randomized. Overall response comparisons did not meet the study’s adjusted significance criterion.
source: China · aplastic-anemia study
Are there Chinese randomized trials?
Yes, but the comparison matters. A 60-patient trial tested adding Shenfu injection to stanozolol plus cyclosporine. Both groups already received stanozolol, and the clinical-response difference was not significant. It cannot establish stanozolol’s independent benefit.
source: China · adjunct-treatment randomized trial, Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica. PMID 15806975.
Does stanozolol dry out or damage joints?
The cited laboratory study does not establish either claim. It measured cultured cells, not joint lubrication, pain or tendon injuries in users.
A fibroblast experiment cannot establish the mechanism or incidence of joint discomfort. New pain, swelling, or loss of function needs clinical assessment.
source: Joint claims · cell experiment, Agents and actions. PMID 8079819.
What does the human SHBG experiment show?
It shows androgen-responsive biological activity. Stanozolol lowered SHBG much more in controls than in people with androgen insensitivity.
The SHBG response shows androgenic activity but does not measure athletic benefit or muscle selectivity. A separate study documented suppression of circulating testosterone.
source: SHBG · androgen-response study
Is 82.1 hours a human half-life?
No. 82.1 hours came from intramuscular stanozolol in horses. It should not be used as the human oral or injectable value.
The cited 82.1-hour value applies to an intramuscular horse study. The human studies do not supply a validated terminal half-life for each oral and injectable preparation.
source: Half-life · horse pharmacokinetics, Journal of veterinary pharmacology and therapeutics. PMID 17348894.
source: Formulation-specific half-life evidence, Human stanozolol trials and equine pharmacokinetic literature.
Is a former US brand the same as a current approved medicine?
No. FDA withdrew the Winstrol tablet approval in 2010. The separate Winsteroid approval was withdrawn in 2024 for failure to submit required reports.
These US decisions do not summarize every country’s medical practice. Chinese clinical use and research should be described with their own source, indication and date.
source: FDA · Winstrol withdrawal
source: FDA · Winsteroid withdrawal
source: China · aplastic-anemia study
Studies and sources
Oral stanozolol · HDL and LDL
Controlled crossover study
JAMA. PMID 2915439.
In 11 male weightlifters studied over six weeks, oral stanozolol lowered HDL cholesterol by 33% and raised LDL by 29%. The injectable testosterone comparison lowered HDL by 9% and LDL by 16%.
Oral stanozolol and injectable testosterone differed in molecule, route and regimen. This is not an oral-versus-injectable stanozolol comparison.
Read the original sourceEndurance training · placebo comparison
Double-blind controlled trial
Medicine and science in sports. PMID 798110.
Twenty-one men trained for three weeks in a double-blind study. Stanozolol did not significantly outperform control for endurance, strength, body weight or skinfold measures.
A short endurance-training study cannot exclude every effect under different conditions.
Read the original sourceOlder adults · activity and body composition
Double-blind controlled trial
Rheumatology and rehabilitation. PMID 139671.
In a four-month double-blind rehabilitation study, weight increased mainly through body fat. Investigators found no anabolic effect or drug-related fluid retention, although activity increased in the stanozolol group.
The abstract does not supply a sample size. It did not assess a cosmetic “dry” appearance.
Read the original sourceCOPD · combination trial
Randomized controlled trial
Chest. PMID 9674442.
Of 23 undernourished men with COPD, 17 completed a 27-week randomized study. The steroid group gained about 1.8 kg versus a 0.4 kg loss in controls, with lean-mass gains but no improvement in walking distance or maximal exercise capacity.
- Treatment
- Oral stanozolol plus an initial testosterone injection and rehabilitation.
This combination cannot isolate the effect of stanozolol.
Read the original sourceHormone suppression · healthy volunteers
Uncontrolled human intervention
Clinical endocrinology. PMID 6430603.
Nine healthy men took oral stanozolol for 14 days. Testosterone fell 55%, with reductions in LH and SHBG; changes reversed after stopping in this short study.
The study does not define fertility recovery after longer exposure or combinations.
Read the original sourceHereditary angioedema · long-term follow-up
Long-term observational follow-up
The Journal of allergy and clinical immunology. PMID 17765757.
Among 21 hereditary-angioedema patients who continued stanozolol for 20 to 40 years, ten reported treatment-related symptoms, five had reduced HDL and two had elevated triglycerides. Persistent liver-enzyme abnormalities were not found in this follow-up.
This was a selected group of long-term continuers evaluated without an untreated comparator. It documents historical medical use and observed findings, not a population event rate or a performance-use safety estimate.
Read the original sourceStanozolol · liver-injury registry
Prospective adverse-event case series
Journal of clinical and experimental hepatology. PMID 40040852.
Eighteen young men with stanozolol-associated liver injury had marked bilirubin elevations, jaundice and itching, often with relatively modest enzyme abnormalities. Mean symptom latency was 55 days; ten reported other substances.
A series of affected patients cannot estimate the proportion of all users who develop injury.
Read the original sourceInjected stanozolol · severe cholestasis
Case report
Clinical and experimental hepatology. PMID 28856252.
A 19-year-old man developed severe cholestasis and liver dysfunction after intramuscular stanozolol. Bilirubin rose markedly despite little initial liver-enzyme elevation.
This shows that injection does not eliminate liver risk; it does not compare the two routes’ incidence.
Read the original sourceJoint claims · cell experiment
Laboratory cell study
Agents and actions. PMID 8079819.
Stanozolol altered growth-factor responses in cultured skin and synovial fibroblasts. The effects differed by cell type.
The experiment did not measure joint pain, tendon injury or clinical recovery in people.
Read the original sourceSHBG · androgen-response study
Human pharmacology study
The Journal of clinical endocrinology and metabolism. PMID 2723028.
A short intervention reduced SHBG in 25 controls, with much smaller responses in people with androgen insensitivity.
A binding-protein change is not a direct measure of free-hormone benefit, strength or safety.
Read the original sourceChina · aplastic-anemia study
Retrospective comparative study in China
Li HM et al. Chinese Journal of Hematology, 2022;43:157–160.
At Peking Union Medical College Hospital, 74 patients received cyclosporine with stanozolol, with danazol, or alone. Six-month overall response was 65.0%, 42.9% and 40.0%, respectively.
- Participants / model
- Non-severe acquired aplastic anemia; groups of 40, 14 and 20.
Retrospective selection and small groups limit causal comparison. Overall response comparisons were not significant after the stated multiplicity correction. This concerns blood counts, not athletic performance.
Read the original sourceChina · adjunct-treatment randomized trial
Retrospective comparative study
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica. PMID 15806975.
Sixty patients with chronic aplastic anemia were randomized to Shenfu injection plus stanozolol and cyclosporine, or the same background medicines alone. The clinical-response difference was not statistically significant.
Both groups received stanozolol, so the trial tested the added treatment rather than stanozolol versus placebo. The English abstract does not provide enough detail to assess the full methods.
Read the original sourceHalf-life · horse pharmacokinetics
Animal pharmacokinetic study
Journal of veterinary pharmacology and therapeutics. PMID 17348894.
The 82.1-hour stanozolol elimination half-life came from an intramuscular horse study.
It is not an oral or injectable human half-life.
Read the original sourceFDA · Winstrol withdrawal
Regulatory notice
Federal Register, July 21, 2010.
The notice includes withdrawal of NDA 012885 for Winstrol 2 mg tablets following the applicant’s request.
Read the original sourceFDA · Winsteroid withdrawal
Regulatory notice
Federal Register, September 23, 2024.
FDA withdrew NDA 013268 for Winsteroid 2 mg tablets because required reports had not been submitted.
Read the original sourceFDA · steroid-product risks
Regulatory safety review
US FDA, 2017.
FDA describes liver injury, adverse lipids, androgenic effects, mood changes and reproductive suppression associated with anabolic-steroid products.
Class-level harms are not a compound-specific incidence estimate.
Read the original sourceFormulation-specific half-life evidence
Human and animal pharmacokinetic evidence
Human stanozolol trials and equine pharmacokinetic literature.
Human trials and the equine pharmacokinetic paper do not establish a validated terminal half-life for each human oral and injectable formulation.
Why is Stanozolol in B tier?
The B tier reflects direct human medical studies and measured lipid, hormone, and liver harms. Controlled evidence provides little support for healthy-user performance or appearance claims.
how tiers are graded: methodology · every cited source · about reptides.
Research reference, not medical advice. Entries distinguish product labels, study doses and reported protocols. Check the linked source for the product, route and population.