Primobolan (Methenolone) — Mild Anabolic Steroid — Anabolic Steroids
Mild DHT-derivative AAS available in oral and injectable forms, considered one of the safest anabolic steroids with a favorable side-effect profile.
Overview
Methenolone (Primobolan) is a DHT-derivative anabolic steroid available as methenolone acetate (oral, Primobolan tablets) and methenolone enanthate (injectable, Primobolan Depot). Developed by Squibb in 1962, it has been used clinically in Europe and other regions for treatment of muscle wasting, malnutrition, osteoporosis, and anemia, though it was never widely marketed in the United States. Primobolan has a mild anabolic:androgenic ratio of approximately 88:44-57, making it one of the weakest AAS by potency but also one of the most tolerable. It does not aromatize to estrogen, does not cause significant water retention, and the injectable form is not hepatotoxic. The oral form is 17-alpha-alkylated with a methyl group but is considered relatively mild on the liver compared to other oral AAS. Primobolan is notable for its use by female athletes and its association with Arnold Schwarzenegger, who reportedly favored it during his competitive career. It has a strong affinity for androgen receptors and is effective for nitrogen retention and lean mass preservation during caloric restriction. Due to its mild nature, effective doses tend to be relatively high (400-800 mg weekly injectable), making it an expensive compound to use at performance-enhancing doses.
Indications
- Approved (Europe): Muscle wasting, malnutrition, osteoporosis, anemia
- Not FDA-approved in United States
- Unapproved: Lean mass preservation during cutting phases (bodybuilding use)
- Unapproved: Female-appropriate anabolic steroid due to low virilization risk
Mechanism of Action
Methenolone binds the androgen receptor with moderate affinity, producing a favorable anabolic-to-androgenic ratio with tissue selectivity
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Methenolone Enanthate | 400-600 mg | Once weekly | Common bodybuilding dose for males |
| Methenolone Acetate | 50-100 mg | Once daily | Oral form; less effective per mg than injectable |
| Methenolone Enanthate | 50-100 mg | Once weekly | Female dose — low virilization risk |
Safety & Contraindications
- Mild androgenic side effects (lower risk of hair loss and acne than most AAS)
- Oral form is 17-alpha-alkylated — mild hepatotoxicity potential
- Injectable form is NOT hepatotoxic
- Does not aromatize — no estrogen-related side effects
- HPG axis suppression (moderate compared to other AAS)
- Lipid changes: moderate HDL reduction
- Schedule III controlled substance in US
- One of the most commonly counterfeited steroids due to high cost