Head to head
Nandrolone decanoate against Testosterone
A modified androgen against the hormone itself. The medical record for nandrolone is real, in dialysis and in bone, and it was still withdrawn in most markets, which is a useful reminder that a trial record and market availability are separate facts.
Column A
Nandrolone decanoateNandrolone decanoate, injectable 19-nortestosterone ester
Randomised trials in dialysis, in burns, and a 2025 meta-analysis in postmenopausal osteoporosis. The medical record is real and the drug was withdrawn in most markets anyway.
Column B
TestosteroneTestosterone, the principal androgen
The best-evidenced hormone on this site. A 5,246-man randomised trial settled the cardiovascular question, and 36 randomised trials in 8,480 women cover the half of the population nobody talks about.
Side by side, on the facts we can check
| Attribute | Nandrolone decanoate | Testosterone |
|---|---|---|
| Category | Muscle & Performance | Hormone |
| FDA status | Previously FDA-approved for anaemia of renal insufficiency. Withdrawn from the United States market. Schedule III controlled substance. Still licensed in some other countries. | FDA-approved for male hypogonadism in multiple formulations. Schedule III controlled substance in the United States. No testosterone product is approved for women in the United States, which is a documented gap rather than a judgement on the evidence. |
| Half-life | Roughly 6 to 12 days as the decanoate ester, so it is dosed weekly or less often. Detectable metabolites persist far longer, which matters for anyone subject to drug testing. | Free testosterone itself clears in minutes to hours. What determines dosing is the ester: cypionate and enanthate run roughly eight days, propionate under a day, and undecanoate several weeks. The ester pages cover what that means in practice. |
| Molecular weight | 428.6 Da for the decanoate ester. A steroid ester, not a peptide. | 288.4 Da. A steroid, not a peptide. |
| Mechanism | 19-nortestosterone, testosterone lacking the 19-carbon methyl group, esterified with decanoic acid for a long-acting oil depot. It binds the androgen receptor with high affinity and is a poor substrate for aromatase, so it produces relatively little oestradiol. Crucially it is reduced by 5-alpha-reductase to dihydronandrolone, which is a weaker androgen than the parent, the opposite of what happens with testosterone. That is why it is comparatively less androgenic in tissues rich in 5-alpha-reductase such as scalp and prostate, and it is also part of why it has distinct central effects, including a well-documented association with sexual dysfunction that patients often find surprising given it is an anabolic steroid. | A 19-carbon steroid synthesised from cholesterol, mainly in the Leydig cells of the testis under luteinising hormone control, and in smaller amounts by the ovary and adrenal in women. It acts directly on the androgen receptor, a nuclear receptor that binds DNA and alters transcription. Two conversions matter clinically: 5-alpha-reductase converts it to dihydrotestosterone, a more potent androgen responsible for much of the effect on scalp hair and prostate, and aromatase converts it to oestradiol, which is responsible for much of its effect on bone, mood and libido in men. Exogenous testosterone suppresses luteinising hormone and follicle-stimulating hormone through negative feedback, which is why it reduces sperm production and testicular size. |
| Human studies cited | 3 | 2 |
| Legal status, US | Withdrawn from the market; Schedule III | FDA-approved, prescription only |
Frequently asked questions
What is the difference between Nandrolone decanoate and Testosterone?
Nandrolone decanoate: Randomised trials in dialysis, in burns, and a 2025 meta-analysis in postmenopausal osteoporosis. The medical record is real and the drug was withdrawn in most markets anyway. Testosterone: The best-evidenced hormone on this site. A 5,246-man randomised trial settled the cardiovascular question, and 36 randomised trials in 8,480 women cover the half of the population nobody talks about.
Which has stronger research evidence, Nandrolone decanoate or Testosterone?
This database does not grade compounds. It counts what was run in people: 3 of the 4 studies cited on the Nandrolone decanoate profile were human work, against 2 of 5 for Testosterone. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are Nandrolone decanoate and Testosterone FDA-approved?
Nandrolone decanoate: Previously FDA-approved for anaemia of renal insufficiency. Withdrawn from the United States market. Schedule III controlled substance. Still licensed in some other countries.. Testosterone: FDA-approved for male hypogonadism in multiple formulations. Schedule III controlled substance in the United States. No testosterone product is approved for women in the United States, which is a documented gap rather than a judgement on the evidence..
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.