Methenolone
Also known as: primobolan, primo
The 'primobolan' steroid: a mild androgen with one of the largest reputation-to-evidence gaps in this library.
Legal status: UK: Class C controlled drug and prescription-only medicine. Supplying it (including to friends) and importing it by post are criminal offences; personal possession for your own use generally is not. Checked 2026-07-26.
Prohibited in sport: Yes — on the WADA Prohibited List.
Approved medical use: Has been licensed in some countries for anaemia and for the recovery of lean mass after debilitating illness.
What it is
Methenolone is a DHT-derived steroid available historically as both an injectable ester and an oral form. It does not aromatise. It carries an unusually strong cultural reputation as the 'safe', 'clean' or 'celebrity' steroid, and it is one of the most frequently counterfeited compounds because of it.
Where licensed it has been used under supervision for anaemia and for restoring lean mass after wasting illness, at levels well below performance use.
What’s claimed
- Lean gains with very few side effects
- Suitable for women and for beginners
- 'Safe enough' for long-term use
What the evidence shows
The anabolic effect is genuine but weak relative to other compounds, which is precisely why the side-effect profile looks favourable: you are comparing a milder drug at a milder effect, not getting something for nothing. The 'safe steroid' framing is not supported: it still suppresses natural testosterone production and still shifts lipids adversely. Its clinical evidence base is thin and old (Bronze), and the counterfeiting rate means what is in the vial is frequently not methenolone at all.
The risks
- Endocrine: suppression of the body's own testosterone production, with testicular atrophy and impaired fertility. Recovery is not guaranteed and can be slow or incomplete.
- Lipids: marked lowering of HDL ('good') cholesterol and raising of LDL, an adverse cardiovascular shift that is more pronounced with oral compounds.
- Androgenic: acne, male-pattern hair loss in those predisposed, and in women virilising effects, deepening of the voice, facial hair growth and clitoral enlargement, some of which do not reverse.
- Product risk: manufactured outside any regulatory system. Independent testing repeatedly finds these products mislabelled, under- or over-concentrated, or containing entirely different active drugs, so the real exposure is unknowable from the label.
- Framing risk: the 'mild and safe' reputation drives longer, less cautious use, which is its own hazard independent of the pharmacology.
What needs monitoring
- Full blood count, including haematocrit and haemoglobin
- Lipid profile
- Blood pressure
- Liver and kidney markers
- Testosterone and the wider hormonal axis: a doctor is the right person to arrange these tests and to interpret what they show.
Sources
- NHS. Anabolic steroid misuse — health risks and the law.
- GOV.UK. Controlled drugs: Misuse of Drugs Act 1971 drug classes.
- World Anti-Doping Agency. The Prohibited List.
- Pope HG, et al. Adverse health consequences of performance-enhancing drugs: an Endocrine Society scientific statement. Endocr Rev. 2014;35(3):341-375.