Common use
Mesterolone is a synthetic androgen derived from dihydrotestosterone (DHT). Internationally, it has been prescribed to treat androgen deficiency in adult men, particularly when symptoms include reduced libido, low energy, decreased muscle mass, and diminished sense of well‑being. Because mesterolone does not convert to estrogen, clinicians may utilize it in scenarios where maintaining a low estrogen burden is desirable, such as men who develop estrogen‑related side effects with other androgen therapies.
Another area of historical use is male infertility. Some studies suggest mesterolone may improve certain sperm parameters, including motility, in selected patients with idiopathic oligospermia. Results are mixed, and not every patient benefits. It has also been explored to support sexual function in men with normal or borderline testosterone who have persistent erectile dysfunction or low libido despite other interventions. Importantly, mesterolone is not approved by the U.S. Food and Drug Administration, and it is not intended for muscle‑building or performance enhancement; use for sports is prohibited by anti‑doping agencies.
Dosage and direction
Dosing varies based on indication, patient characteristics, and local product labeling. In countries where it is licensed, clinicians often start with low to moderate oral doses divided through the day, then adjust based on symptom response, laboratory values, and tolerability. For hypogonadal symptoms, a common approach is an initial daily dose split into two or three administrations with meals to support consistent serum levels. For fertility‑related use, courses may extend across several months with periodic reassessment of semen analysis and endocrine markers.
Because mesterolone is an androgen, individualized titration and ongoing monitoring are essential. Your clinician may periodically check hematocrit, lipids, liver enzymes, prostate‑specific antigen (PSA), and testosterone/free testosterone or sex hormone–binding globulin (SHBG) to gauge effect and safety. Never self‑medicate or alter the dose without professional guidance. In the United States, mesterolone is not FDA‑approved and is not available through routine prescribing; if you live in a country where it is approved, follow that nation’s official labeling and your clinician’s instructions precisely.
Precautions
All androgens require careful screening and follow‑up. Men with a personal or family history of prostate cancer or significant benign prostatic hyperplasia (BPH) should discuss risk–benefit thoroughly and undergo appropriate prostate monitoring. Androgens can stimulate erythropoiesis; if hematocrit rises excessively, the risk of thrombosis may increase. Mesterolone may affect cholesterol profiles, particularly HDL, so baseline and follow‑up lipid panels are prudent, especially in those with cardiovascular risk.
Although mesterolone is not 17‑alpha‑alkylated and is considered to have a lower risk of liver toxicity compared with many oral anabolic agents, hepatobiliary caution is still warranted; report right‑upper‑quadrant pain, dark urine, or jaundice promptly. People with uncontrolled sleep apnea, severe heart, liver, or kidney disease, or a history of androgen‑responsive tumors need stringent medical oversight or may be advised against therapy. Mesterolone should not be used by women, particularly those who are pregnant or breastfeeding, due to the risk of virilization in the fetus or infant. Adolescents should avoid it because of potential effects on growth plates and endocrine development.
Contraindications
Mesterolone is contraindicated in known or suspected prostate or male breast cancer, pregnancy, and breastfeeding. It should not be used in patients with hypersensitivity to mesterolone or any excipients in the formulation. Clinicians typically avoid androgens in individuals with severe hepatic impairment, nephrotic syndrome, uncontrolled heart failure, or polycythemia unless the benefits clearly outweigh the risks and intensive monitoring is feasible. Because it is not FDA‑approved in the U.S., its use is also limited by regulatory status.
Possible side effects
Commonly reported effects include increased libido, changes in mood or irritability, acne, oily skin, and mild hair loss in those with androgen‑sensitive follicles. Some individuals notice fluid retention or changes in blood pressure. Laboratory changes can include reduced HDL cholesterol, altered LDL cholesterol, increased hematocrit, and shifts in SHBG that change free hormone levels. Because mesterolone is a DHT derivative and not aromatized, estrogen‑related effects such as gynecomastia and water retention may be less prominent than with aromatizable androgens, but individual responses vary.
Less common but important risks involve prostate enlargement symptoms (weaker urine stream, nocturia), elevation of PSA, and rare hepatic adverse effects. Psychological effects can include restlessness, aggression, or mood swings; if these occur, dosing and risk–benefit should be re‑evaluated. Androgens can suppress spermatogenesis at certain doses in some men, though mesterolone has been studied for infertility as well—highlighting the need for individualized care and realistic expectations. Any signs of chest pain, severe headache, shortness of breath, jaundice, or sudden leg swelling warrant urgent medical evaluation.
Drug interactions
Androgens may potentiate the anticoagulant effect of warfarin and other vitamin K antagonists, raising bleeding risk; more frequent INR monitoring and dose adjustments may be needed. They can also impact glucose metabolism, potentially reducing insulin or oral hypoglycemic requirements; diabetes regimens may need reassessment. Concomitant use with systemic corticosteroids or ACTH can increase edema risk, particularly in patients with cardiac, renal, or hepatic disease.
Mesterolone may reduce thyroxine‑binding globulin, altering lab values without necessarily changing clinical thyroid status. Antiandrogens (for example, spironolactone, flutamide) can blunt therapeutic effects, while 5‑alpha‑reductase inhibitors (finasteride, dutasteride) do not block mesterolone directly but may influence overall androgen milieu. Excessive alcohol or hepatotoxic drugs demand caution even though mesterolone is not highly hepatotoxic. Always share a full medication and supplement list with your healthcare team, including PDE‑5 inhibitors, fertility medicines, and over‑the‑counter products.
Missed dose
If you miss a dose, take it as soon as you remember unless it is close to the time for your next scheduled dose. If it is near the next dose, skip the missed dose and resume your regular schedule. Do not double up to make up for a missed dose. If you miss doses frequently, speak with your clinician about strategies to improve adherence.
Overdose
Acute overdose is uncommon, but excessive androgen exposure may cause pronounced acne, mood changes, headache, fluid retention, elevated blood pressure, or significant changes in hematocrit and lipids. If a substantial overdose is suspected or worrisome symptoms occur, seek medical attention promptly. Clinicians will provide supportive care, evaluate vital signs and laboratory parameters, and advise on temporary discontinuation or dose adjustment. Never take more than prescribed or sourced through legitimate medical channels.
Storage
Store tablets at room temperature away from excess heat, moisture, and direct light. Keep medications in their original containers with child‑resistant caps, out of reach of children and pets. Do not store in a bathroom or humid environment. Do not use after the expiration date. For safe disposal, use a pharmacy take‑back program when available; avoid flushing unless labeling specifically instructs it.
U.S. Sale and Prescription Policy: buy Mesterolone without prescription?
In the United States, mesterolone (often known by the brand name Proviron internationally) is not FDA‑approved and is regulated as an anabolic‑androgenic agent. U.S. law does not permit purchasing or possessing prescription‑only or controlled substances without a valid prescription from a licensed practitioner. Attempting to “buy mesterolone without a prescription” from unverified sources is unsafe and may be illegal, exposing you to counterfeit products, health risks, and legal consequences.
HealthSouth Rehabilitation Hospital of Las Vegas is committed to patient safety and regulatory compliance. We do not dispense mesterolone without a valid prescription and appropriate clinical oversight. Our pharmacists can provide education about androgen therapies, discuss safer, evidence‑based alternatives that are FDA‑approved, and, when appropriate, help you connect with licensed healthcare providers for legitimate evaluation. If a clinician determines that androgen therapy is suitable, we support lawful, transparent dispensing through proper channels, with monitoring and follow‑up to protect your health and ensure compliance with U.S. regulations.
