Nandrolone Decanoate
Deca · Nandrolone Deca
Long-acting 19-nor (Deca-Durabolin); collagen/joint benefits, very long clearance.
Key takeaways
- Long-acting 19-nor injectable (Deca-Durabolin); clinical history in anemia, osteoporosis, and cachexia.
- ~10.2-day half-life, peak around 1.8 days; once- or twice-weekly injection.
- Aromatizes at ~20% of testosterone's rate; androgenic sides are comparatively mild.
- Detection window runs 4–9 months via 19-norandrosterone; suppression is deep and recovery slow.
Overview
What it is
Nandrolone decanoate (Deca-Durabolin) is the decanoate ester of 19-nortestosterone, introduced clinically for anemia, osteoporosis, and cachexia. It aromatizes weakly (about 20% of testosterone's rate, preferentially to estrone) and 5-alpha-reduces to the weaker dihydronandrolone, so its androgenic side-effect profile is comparatively mild.
Pharmacokinetics
The ~10.2-day half-life peaks around 1.8 days post-injection with ~73% bioavailability. Levels build over many weeks and clear just as slowly; documented protocols inject once or twice weekly.
Harm reduction
Not hepatotoxic. The real concerns are profound, slow-to-recover HPTA suppression, progestogenic activity, and an exceptionally long detection window: the 19-norandrosterone metabolite stays detectable for 4–9 months after controlled dosing.
Reported dosing protocols
Protocols reported in research literature and clinic/community use — informational context, not a dosing recommendation.
| Use case | Dose | Route | Frequency | Duration |
|---|---|---|---|---|
| Anemia / cachexia (clinical) | 50–200 mg | IM | Every 1–4 weeks | Months |
| Performance (community) | 200–400 mg weekly | IM | 1–2× weekly | 8–12 weeks |
Pharmacokinetic summary
- Model tier
- Advanced (t½ + Cmax + Tmax + F)
- Half-life
- 10 days
- Cmax
- 800 ng/dL
- Tmax
- 1.8 days
- Bioavailability
- 73%
- Typical dose
- 100–400 mg
Harm reduction
- Aromatizes
- Yes
- DHT derivative
- No
- Injection frequency
- 1–2×/week
Frequently asked questions
What was Deca prescribed for?
Anemia, osteoporosis, and wasting conditions including HIV-associated cachexia. It raises red-cell production and nitrogen retention with weaker androgenic effects than testosterone, which made it attractive for frail patients before newer agents took over.
Why is Deca called a slow compound?
The decanoate ester's ~10-day half-life means blood levels take 4–6 weeks to saturate, so results arrive gradually. Clearance is just as slow: meaningful levels persist for weeks after the last injection, which is why PCT timing starts late.
What is "Deca dick"?
Community shorthand for the libido and erectile problems some users report on nandrolone-heavy runs. The proposed mechanism is progestogenic activity plus low DHT, since nandrolone reduces to a weaker androgen. Stacking with testosterone is the standard reported countermeasure.
References
- JCEM nandrolone decanoate
- Nandrolone decanoate PK study (JCEM) — Primary human pharmacokinetic source for the half-life and peak timing.
- Nandrolone esters: pharmacokinetics and pharmacodynamics (review) — Comparative ester PK; decanoate vs phenylpropionate release profiles.
Related articles
Related compounds
Nandrolone Phenylpropionate
Short-acting 19-nor (NPP); faster clearance than Deca. Good for frontloading.
Testosterone Enanthate
Long-acting testosterone ester; the most common TRT and cycle base. Reaches steady state in ~5 weeks.
Testosterone Cypionate
Standard US TRT ester with a slightly longer release tail than enanthate. Steady state ~4–5 weeks.
Protocols featuring Nandrolone Decanoate
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