Nandrolone

a 19-nor androgen with formulation-specific human PK for decanoate and phenylpropionate, historical US approvals, and a currently authorized Australian decanoate product.

tier A · androgens · 7 to 12 days human decanoate apparent terminal half-life

verdict

nandrolone has real human depot pharmacokinetics, but each number belongs to a named ester, oil vehicle, volume, site, and study design.

if you are asking whether Deca and NPP have the same half-life — no. decanoate and phenylpropionate release at different rates, and Minto showed that injection volume and gluteal versus deltoid site also changed absorption.

if you are asking whether Deca-Durabolin is still FDA-approved — no. FDA withdrew NDA 013132 effective December 19, 2024 at the sponsor's request because it was no longer marketed. an Australian decanoate product remains authorized.

if you are asking what the displayed number means — 228 hours is the midpoint of a published 7-to-12-day apparent terminal half-life range after human intramuscular nandrolone decanoate. it does not describe phenylpropionate or free nandrolone clearance.

The page separates apparent depot terminal half-life, ester absorption half-time, and free-parent clearance. They are different endpoints.

why A-tier

A tier reflects strong human formulation-specific PK, controlled biomarker data, clear product identities, and current foreign authorization. The real gap is the absence of a modern pivotal outcome and contemporary long-term safety package.

the core tension

Nandrolone has the cohort's best human ester-PK comparison, and that study shows exactly why a universal Deca half-life or a parent-to-ester shortcut is misleading.

what it is

Nandrolone is 19-nortestosterone. Medical injectable products used ester prodrugs in oil, principally nandrolone decanoate and nandrolone phenylpropionate. Ester hydrolysis releases free nandrolone after depot absorption.

what it does

Free nandrolone activates the androgen receptor. In androgen-sensitive tissue, 5-alpha-reductase can form dihydronandrolone, which is less androgenically active than dihydrotestosterone. Animal work reports aromatization and clinical reviews describe progestogenic activity, but quantitative human conversion is not established.

origin

Durabolin phenylpropionate and Deca-Durabolin decanoate were historical US products. Their approvals were withdrawn in 2018 and 2024. Australia currently lists Deca-Durabolin nandrolone decanoate as an active ARTG entry.

why researchers are interested

The long oil-depot curve and medical history are often compressed into a single Deca stereotype. The primary PK studies show why that is wrong: ester, volume, site, and whether one reports absorption or terminal decline all matter.

does it work

This file supports human pharmacokinetic and biomarker conclusions, not a general muscle claim. A randomized 8-week nandrolone decanoate arm in weightlifters found no change in most lipid measures and a selective lipoprotein(a) decrease, a result that does not transfer to higher doses or stacks.

claims vs the data

• Deca has a single universal half-life — contradicted — human data show site, volume, dose, and endpoint-dependent values.
• NPP can use the decanoate curve — contradicted — phenylpropionate peaked earlier and had a shorter absorption half-time.
• nandrolone always destroys lipids — overstated — one randomized 200 mg/week single-compound arm found no change in most lipid markers; this does not clear higher or combined exposures.

key facts

• molecular formula: C28H44O3 (decanoate); C27H34O3 (phenylpropionate)
• molecular weight: 428.66 g/mol (decanoate); 406.57 g/mol (phenylpropionate)
• amino acids: n/a (steroidal small molecule, not a peptide)
• half-life: decanoate apparent terminal half-life 7 to 12 days in humans; phenylpropionate has a different, shorter absorption profile
• type: 19-nor anabolic-androgenic steroid administered historically as intramuscular decanoate or phenylpropionate ester
• CAS: 360-70-3 (decanoate); 62-90-8 (phenylpropionate)
• 7 to 12 d human decanoate terminal range
• 23 participants in ester, site, and volume PK study
• 2 distinct historical human esters on this page
• 2024 Deca-Durabolin US withdrawal effective

frequently asked questions

What is nandrolone decanoate's half-life?

One human study reported an apparent terminal range of 7 to 12 days after single intramuscular decanoate doses. The page displays the 9.5-day midpoint and preserves the full range.

Does that number apply to nandrolone phenylpropionate?

No. Phenylpropionate peaked earlier and had a shorter absorption half-time in the human ester-comparison study.

Why do site and volume matter?

For oil depots, release from the injection site can be the slow step. Minto reported slower decanoate absorption from a 1 mL deltoid injection than from comparable gluteal administration.

Is nandrolone approved anywhere?

It is not currently FDA-approved. Australia's TGA lists an authorized nandrolone decanoate product, so the current status is approved abroad.

related peptides

• testosterone — the other clinically characterized injectable androgen
• Trenbolone — another 19-nor androgen with no modern human therapeutic PK
• Boldenone — a veterinary long-ester comparator with animal-only PK

reptides grades the research record and cites the literature behind every call. research reference only; not medical advice.