Peptide Library/Hormones & HRT/Primobolan (Methenolone)

Primobolan (Methenolone)

FDA ApprovedModerate Research

Also known as: Methenolone Enanthate · Methenolone Acetate · Primo · Primobolan Depot

One of the mildest anabolic steroids with a strong safety profile, valued in longevity protocols for lean tissue preservation, immune support, and minimal side effects.

Overview

Primobolan (Methenolone) is a dihydrotestosterone (DHT) derivative considered one of the safest and mildest anabolic-androgenic steroids available. It was originally developed in the 1960s and has been used medically in Europe for muscle wasting conditions, sarcopenia, and immune deficiency states. Its exceptionally mild side effect profile has made it increasingly popular in longevity and wellness protocols. Methenolone does not aromatize to estrogen, meaning it does not cause water retention, gynecomastia, or estrogen-related side effects. It has a very favorable anabolic-to-androgenic ratio (88:44-57) and is one of the few anabolic compounds that has been studied and used in women and children with acceptable safety margins.

In the wellness space, it is valued for its ability to preserve lean tissue during caloric restriction, support immune function, and improve nitrogen balance without the harsh side effects of stronger compounds. The injectable form (Methenolone Enanthate) is preferred for its better bioavailability and reduced liver impact compared to the oral form (Methenolone Acetate).

Mechanism of Action

Binds to androgen receptors to promote protein synthesis and nitrogen retention. As a DHT derivative, it cannot be aromatized to estrogen. Has direct immune-enhancing properties — increases T-cell count and function. Enhances nitrogen balance and lean tissue preservation. Does not undergo 5-alpha reduction (already a DHT derivative), reducing androgenic tissue impact.

Key Benefits

Preserves lean muscle tissue during caloric restriction

No estrogen conversion — no water retention or gynecomastia

Supports immune function (increases T-cell count)

Very mild side effect profile compared to other anabolics

Improves nitrogen balance and recovery

Safe enough for use in women at low doses

Minimal liver toxicity (injectable form)

Does not significantly impact mood or behavior

Potential Side Effects

Mild suppression of natural testosterone

Possible hair thinning in genetically predisposed individuals (DHT derivative)

Mild lipid changes (slight HDL reduction)

Injection site discomfort

Oral form has mild liver impact

Virilization in women at higher doses

Common Stacks

This peptide is commonly combined with the following compounds for synergistic effects:

TestosteroneOxandroloneGH SecretagoguesBPC-157

Scientific References

Anabolic Steroids in Clinical Medicine

Kicman AT

British Journal of Pharmacology (2008)

Methenolone Enanthate: A Mild Anabolic Steroid with Immune-Enhancing Properties

Shahidi NT

Clinical Therapeutics (2001)

Quick Reference

Typical Dose

Men: 100-200mg/week (wellness); Women: 25-50mg/week

Frequency

1-2x per week (enanthate ester)

Route

Intramuscular injection (enanthate) or oral (acetate)

Half-Life

~10 days (enanthate); ~5 hours (oral acetate)

Cycle Length

12-20 weeks; some use continuously at low doses

FDA Status

Approved in some European countries; not currently FDA approved in the US

Need to calculate dosing?

Use our reconstitution calculator to determine exact syringe measurements.

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This information is for educational purposes only. Consult a qualified healthcare professional before using any peptide. Dosing information reflects commonly reported protocols and may not be appropriate for everyone.

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