Primobolan Enanthate (Methenolone Enanthate)
Methenolone Enanthate · Primo E
Methenolone enanthate, marketed as Primobolan Depot, is a long-ester injectable anabolic-androgenic steroid derived from dihydrotestosterone (DHT). Developed by Schering AG in the early 1960s, it has a long history of medical use in Europe and Japan for muscle wasting, osteoporosis, and anemia. It is considered one of the mildest injectable AAS - anabolic-to-androgenic ratio roughly 88:44-57 - with virtually no estrogenic activity and very low androgenic side-effect burden.
Starting dose. 300-400mg/week — (men), 50-75mg/week (women)
Split weekly total into 2 injections for stable levels (enanthate ester, ~7-10 day half-life). Compatible with other oil-based AAS in the same syringe. Higher doses required for visible effect due to mild activity - plan 400mg/week minimum for men.
Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.
How it works
Methenolone binds the androgen receptor (AR) with modest affinity and drives protein synthesis and nitrogen retention. As a DHT derivative, it does not aromatize to estrogen and has no intrinsic estrogenic activity.
Unusually for an AAS, methenolone exhibits relatively weak HPT-axis suppression at low-to-moderate doses - endogenous testosterone production is reduced but often not completely shut down. At higher bodybuilding doses (400mg+/week), full suppression does occur and a testosterone base is standard.
It is not 17-alpha-alkylated (rare for a DHT derivative used orally - the oral Primobolan tablets are 17-methylated, a less hepatotoxic modification; the injectable enanthate form bypasses the liver almost entirely). As a result it has a very mild side-effect profile - particularly low androgenic burden, minimal lipid shift, and low virilization risk in women compared to other AAS.
The enanthate ester gives a plasma half-life of ~7-10 days, supporting weekly or 2x-weekly injections.
What to expect
First 3 weeks: little to no visible effect. Some users report slight mood improvement. Steady state takes time.
Weeks 4-8: subtle but steady lean mass preservation, improved muscle hardness. Not dramatic - primobolan is a 'quality over quantity' compound.
Weeks 9-12: sustained conditioning, maintained lean mass in deficit. Diminishing return beyond 12 weeks.
Evidence
References for this compound are being re-checked against their source records. We are not showing them until each one is confirmed to support the claim it sits under.
Side effects & safety
Commonly reported
- Minimal - one of the lowest side-effect AAS
- Modest HPT-axis suppression (dose-dependent)
- Slight lipid shift (less severe than other AAS)
- Possible accelerated hair loss in genetically predisposed users
Less common & notes
- Oily skin, mild acne, minimal androgenic effects at lower doses.
- Women tolerate primobolan better than most AAS but still risk virilization at higher doses.
- Rare: hepatic stress markers elevation (the injectable is not 17-aa and is generally considered non-hepatotoxic).
- Cardiovascular effects minimal at moderate doses.
Pharmacokinetics
Post-injection
IM (oil depot)
Per injection - supports 1-2x weekly dosing
Hepatic metabolism. Renal excretion of metabolites.
Storage. Store at controlled room temperature (20-25°C / 68-77°F). Protect from light. Oil-based solution - do not refrigerate or freeze. Draw with a larger gauge needle and inject with a smaller one (18G draw, 23-25G inject). Keep out of reach of children and in a locked location - Schedule III controlled substance in the United States.
Regulatory status
Schedule III controlled substance in the United States under the Anabolic Steroids Control Act of 1990. Never FDA-approved for human use in the US. Remains approved in some European and Japanese jurisdictions under the Primobolan Depot brand (Bayer / Schering). Possession or distribution without a valid prescription is a federal offense in the United States.
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