At a glance
Effects
- Androgenic / masculinizing: Strong androgenic action supporting secondary male characteristics and libido; used clinically for androgen deficiency.[1][2]
- Raises free testosterone: High SHBG binding affinity (~4x DHT) can increase circulating free testosterone.[2][4]
- No estrogenic effect: Does not aromatize to estrogen, so it does not cause estrogen-driven bloating or gynecomastia.[1]
- Weak anabolic / muscle effect: Low anabolic rating; described as a weak anabolic that is not a standalone mass builder.[5][1]
- Mood / wellbeing: Reported to improve mood and concentration in androgen-deficient states, though evidence is limited.[6]
Anabolic-androgenic steroid (DHT derivative)
Oral (tablets, 25–50 mg)
~12–13 hours
Not 17α-alkylated — no notable hepatotoxicity
Up to ~5–6 weeks in urine; WADA-prohibited
About Mesterolone
Every point here is drawn from public medical and harm-reduction sources. A bracketed number after a claim — like [1]— is a reference: tap it to open the exact source it's based on (numbered list at the bottom). It is not a rating or score. Educational information, not medical advice.
Product specifics
- Est. delivery
- 3–7 business days · EU tracked
Product details as stated by the vendor (claims, not independently verified). Delivery is our standard EU estimate.
What it is
Mesterolone (brand name Proviron) is an orally active androgen and anabolic-androgenic steroid (AAS) derived from dihydrotestosterone (DHT), used mainly to treat low testosterone and androgen deficiency in male hypogonadism.[1][2] It has strong androgenic but weak anabolic effects, so it is rarely used to build mass and is more often taken to support masculinization, libido and as an adjunct in steroid cycles.[1][5]
How it works
Mesterolone is a synthetic agonist of the androgen receptor (AR), the same target as natural testosterone and DHT, and acting through it modulates gene expression in androgen-dependent tissues.[1][2] Structurally it is the 1α-methyl derivative of DHT, which lets it survive oral dosing without C17α-alkylation, the modification that makes many other oral steroids liver-toxic.[3][4] It binds very strongly to sex-hormone-binding globulin (SHBG) — with reported affinity several times that of DHT — which can raise circulating free testosterone, and it has no estrogenic activity.[2][1]
Risks & side effects
Most important: As an androgen, the most important risks are those of androgen excess: chronic high-dose anabolic steroid use can raise blood pressure, cause left-ventricular hypertrophy and premature coronary artery disease, and worsen cholesterol (lower HDL, raise LDL); in men it also risks prostate enlargement, and in women causes irreversible virilization such as voice deepening.[7][8] Despite a vendor flag for liver toxicity, mesterolone is NOT 17α-alkylated and authoritative sources state it carries no notable risk of liver damage.[1][3]
Common
Serious
- Adverse cholesterol shifts (lower HDL, higher LDL) raising cardiovascular risk[9]
- Hypertension, left-ventricular hypertrophy and premature coronary disease with chronic high-dose abuse[7]
- Prostate enlargement / risk of prostatic cancer in men[7][8]
- Irreversible virilization in women (voice deepening, facial hair, menstrual changes)[7][1]
- Premature fusion of growth plates (epiphyses) in adolescents[8]
Safety & harm reduction
- Women, especially if pregnant or breastfeeding — risk of virilization and fetal harm[9][1]
- Men with existing or suspected prostate cancer or prostatic enlargement[7]
- Children/adolescents (risk of premature growth-plate fusion)[8]
- Anyone with significant cardiovascular disease or adverse lipid profile[9][7]
- Can be used to counter the semen-quality effects of antiandrogens like cyproterone (competition at the androgen receptor)[6]
- General AAS class caution with other hepatotoxic or cardiovascular-stressing drugs[8]
- Reported cycle durations are kept short (commonly stated as not beyond ~5–6 weeks) to limit cholesterol/suppression effects — not a prescription[15]
- Often used as an adjunct within other steroid cycles rather than alone; monitor HPG-axis recovery[5][6]
- WADA-prohibited in sport — not for competitive athletes[10]
Dosage context
Commonly-reported, NOT a prescription: clinical product labelling describes 25 mg taken 2–3 times daily for androgen deficiency/infertility, and tablets typically contain 25–50 mg.[5][10] Non-medical/performance use is reported around 50–150 mg/day, but sources disagree and this is not medical advice.[11] Reported terminal half-life is roughly 12–13 hours (some sources cite up to 24 h), so dosing is usually split twice daily.[11][14]
Sources
- 1.DrugBank — Mesterolone
- 2.Synapse — Mechanism of Mesterolone
- 3.Cytech Pharma — Proviron 25 (structure / non-17aa)
- 4.DrugBank article — AAS binding to AR/SHBG
- 5.Bodybuilding Wizard — Proviron guide
- 6.Taylor & Francis — Mesterolone knowledge (link unavailable)
- 7.INCHEM PIM 904 — Mesterolone (clinical effects)
- 8.INCHEM PIM 904 — AAS poisoning effects
- 9.Anabolic Planner — Proviron pharmacology
- 10.NCATS Inxight Drugs — Mesterolone (Wikipedia/label/WADA)
- 11.Anabolic Planner — dosing/half-life
- 12.PMC — Mesterolone analytical paper (clinical use, tablet strength, WADA)
- 13.CrazyBulk — Proviron half-life/SHBG
- 14.Bodybuilding Wizard — half-life/non-hepatotoxic
- 15.Roids101 — Proviron cycle/half-life
This information is provided for educational and harm-reduction purposes only. It is not medical advice. These substances can carry serious health risks; effects and safe use vary by individual. Consult a qualified healthcare professional before use. Legal status varies by country — it is your responsibility to know your local law. We do not encourage misuse.
Other options for Mesterolone· 5 offers
Same compound from different labs/brands and pack sizes. Tap a row to switch brand — the price and buy button update instantly.
This compound comes in different forms (e.g. injectable vs oral vs topical). Cost per mg is only comparable within the same form.
| Brand | Form | Strength | Pack | Price | Per mg |
|---|---|---|---|---|---|
Royal Pharma | blister-pack | 25 mg/tab | 30 tab | 34,90 € | ★€0.047/mg |
Driada | tab | 25 mg/tab | 50 tab | 48,90 € | €0.039/mg |
Generic | blister-pack | 25 mg/tab | 3 tab | 49,90 € | €0.665/mg |
Intex PharmaSelected | blister-pack | 25 mg/tab | 60 tab | 114,99 € | €0.077/mg |
Hemi Pharma | blister-pack | 25 mg/tab | 60 tab | 114,99 € | €0.077/mg |