Nandrolone
Nandrolone Decanoate (Deca-Durabolin), 19-nor AAS. Classic "bulking" AAS with joint recovery effect.
The links above are labelled third-party affiliate links. MolekulaX does not sell and does not verify product quality.
WHAT IS NANDROLONE?
Detailed overview
Nandrolone Decanoate is a 19-nor testosterone derivative, long-acting injectable AAS. **Ester variants**: Decanoate (Deca-Durabolin) ~15-day t1/2, depo-style slow stable release, 1x weekly injection sufficient, more water retention; Phenylpropionate (NPP) ~5-day t1/2, faster on/off profile, 2x weekly injection, anecdotally less water retention. Clinically used for anemia and cachexia. In bodybuilding it is used in "bulking" cycles for muscle mass and joint recovery (collagen synthesis elevation). Aromatase converts it to estrogen minimally (~10% vs testosterone), and 5α-reductase forms dihydronandrolone with only ~20% AR activity (vs DHT, a STRONG AR agonist) – **this is the physiological prostate-sparing basis, one of Nandrolone main advantages over Testosterone**. "Deca-dick" libido drop is a common complaint (prolactin elevation); "Deca-blues" mood anecdote: chronic 19-nor use suspected of dopamine-serotonin balance shift (depressive symptoms reported in some users after 3+ months).
Mechanism
19-nor AAS, AR agonist, weak aromatization
Half-life
15 days (decanoate)
Anabolic ratio
125:37
Legal status
USA: Schedule III. HU/EU: Rx.
Data console
Lab data
Safety
Side effects, stop signs, contraindications
Side effects · 8
- Severe HPTA suppression and prolonged hypogonadism: 19-nor metabolites cause protracted suppression, with testosterone recovery often taking 6-12 months after Deca and frequently requiring extended PCT.
- 'Deca-dick': libido loss and erectile dysfunction driven by prolactin elevation and progesterone-receptor activity, often appearing mid-cycle, especially without a testosterone base.
- Adverse lipid profile: marked drop in HDL cholesterol and rise in LDL (Hartgens 2004), increasing atherosclerosis and long-term cardiovascular risk.
- Mood disturbances ('Deca-blues'): chronic 19-nor use can cause depressive symptoms, irritability and anxiety, typically after 3+ months, linked to neurosteroid and progestogenic activity.
- Water retention and raised blood pressure: the Deca decanoate ester commonly causes notable fluid retention that can elevate blood pressure; the shorter NPP ester anecdotally retains less water.
- Androgenic effects and virilization in women: although dihydronandrolone is a weaker androgen, higher doses can cause acne, hair thinning, and in women voice deepening, hirsutism and clitoral enlargement (partly irreversible).
- Injection-site reactions (PIP): pain, swelling and lumps from oily IM injections, typically stronger on the short-ester NPP carrier than on Deca; rarely sterile abscess or infection.
- Mild estrogenic effects: despite minimal (~10%) aromatization, sensitive users can still develop gynecomastia and edema, which prolactin elevation can further aggravate.
Contraindications · 7
- Pregnancy and breastfeeding: androgenic/anabolic steroids are teratogenic and can virilize the fetus, so they are absolutely contraindicated in pregnancy.
- Androgen-sensitive cancer: contraindicated in known or suspected prostate carcinoma or male breast cancer, as it can drive androgen-stimulated progression.
- Hyperprolactinemia / prolactinoma: elevated baseline prolactin or a prolactinoma is a contraindication, as nandrolone's progestogenic activity further raises prolactin and worsens symptoms.
- Planning fatherhood / fertility needs: avoid due to prolonged HPTA suppression and impaired spermatogenesis (6-12 month recovery after Deca) when conception is a near-term goal.
- Cardiovascular disease and uncontrolled hypertension: contraindicated in pre-existing heart disease or hypertension due to HDL suppression, water retention and raised blood pressure.
- Severe hepatic or renal impairment: although the injected ester spares the liver, it is contraindicated with reduced hepatic/renal function and the edema tendency from fluid retention.
- Active athlete subject to doping tests: nandrolone is WADA-banned and has the longest detection window among AAS (12-18 months in urine), so it must be avoided in competitive sport.
Related Performance Compounds
Same therapeutic category
Studies
Related research and clinical findings
The effects of supraphysiologic doses of testosterone on muscle size and strength in normal men
Bhasin S, Storer TW, Berman N et al.
Effects of nandrolone decanoate on serum lipoprotein profile
Hartgens F, Rietjens G, Keizer HA et al.
Anabolic steroid-induced hypogonadism: diagnosis and treatment
Rahnema CD, Lipshultz LI, Crosnoe LE et al.
Telegram
Have a question about Nandrolone?
Reach out to an advisor on Telegram. Performance compounds are presented with a harm-reduction approach, based on peer-reviewed evidence.
The information here is for educational and scientific purposes only. Performance-enhancing compounds (AAS, prohormones, stimulants, doping agents) are illegal without prescription in Hungary and most of the EU, and carry serious health and legal risks. WADA bans them in competitive sport. This is NOT a usage guide, and we do not encourage any illegal use. If you do use them, medical supervision and regular bloodwork are ESSENTIAL. Severe endocrine, cardiovascular, hepatic and psychiatric side effects are possible.