mesterolone mesterolone mesterolone, sold under the brand name proviron among others, is an androgen and anabolic steroid (aas) medication which is used mainly in the treatment of low testosterone levels. it has also been used to treat male infertility, although this use is controversial. it is taken by mouth. not to be confused with mestanolone. mesteroloneclinical datatrade namesproviron, othersother namesnsc-75054; sh-60723; sh-723; 1α-methyl-4,5α-dihydrotestosterone; 1α-methyl-dht; 1α-methyl-5α-androstan-17β-ol-3-oneahfs/drugs.cominternational drug namesroutes ofadministrationby mouthdrug classandrogen; anabolic steroidatc codeg03bb01 (who) legal statuslegal status au: s4 (prescription only) ca: schedule iv us: schedule iii pharmacokinetic databioavailability3%protein binding98% (40% to albumin, 58% to shbg)metabolismliverelimination half-life12-13 hoursexcretionurineidentifiers iupac name (1s,5s,8r,9s,10s,13s,14s,17s)-17-hydroxy-1,10,13-trimethyl-1,2,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydrocyclopentaphenanthren-3-one cas number1424-00-6 npubchem cid15020chemspider14296 yunii0srq75x9i9keggd04947 ychemblchembl258918 ycomptox dashboard (epa)dtxsid90878533 echa infocard100.014.397 chemical and physical dataformulac20h32o2molar mass304.474 g·mol−13d model (jsmol)interactive image smiles o=c4c3cc2(cc1(c)(o)cc12)3(c)(c)c4 inchi inchi=1s/c20h32o2/c1-12-10-14(21)11-13-4-5-15-16-6-7-18(22)19(16,2)9-8-17(15)20(12,13)3/h12-13,15-18,22h,4-11h2,1-3h3/t12-,13-,15-,16-,17-,18-,19-,20-/m0/s1 ykey:uxyrzjkiqkrjcf-tzpfwljssa-n y ny (what is this?) (verify) side effects of mesterolone include symptoms of masculinization like acne, scalp hair loss, increased body hair growth, voice changes, and increased sexual desire. it has no risk of liver damage. the drug is a synthetic androgen and anabolic steroid and hence is an agonist of the androgen receptor (ar), the biological target of androgens like testosterone and dihydrotestosterone (dht). it has strong androgenic effects and weak anabolic effects, which make it useful for producing masculinization. the drug has no estrogenic effects. mesterolone was first described by 1966 and introduced for medical use by 1967. in addition to its medical use, mesterolone has been used to improve physique and performance, although it is not commonly used for such purposes due to its weak anabolic effects. the drug is a controlled substance in many countries and so non-medical use is generally illicit. medical uses mesterolone is used in the treatment of androgen deficiency in male hypogonadism, anemia, and to support male fertility among other indications. it has also been used to treat delayed puberty in boys. because it lacks estrogenic effects, mesterolone may be indicated for treating cases of androgen deficiency in which breast tenderness or gynecomastia is also present. the drug is described as a relatively weak androgen with partial activity and is rarely used for the purpose of androgen replacement therapy, but is still widely used in medicine. mesterolone is used in androgen replacement therapy at a dosage of 50 to 100 mg 2 to 3 times per day. androgen replacement therapy formulations and dosages used in men routemedicationmajor brand namesformdosage oraltestosteronea–tablet400–800 mg/day (in divided doses) testosterone undecanoateandriol, jatenzocapsule40–80 mg/2–4x day (with meals) methyltestosteronebandroid, metandren, testredtablet10–50 mg/day fluoxymesteronebhalotestin, ora-testryl, ultandrentablet5–20 mg/day metandienonebdianaboltablet5–15 mg/day mesterolonebprovirontablet25–150 mg/day sublingualtestosteronebtestoraltablet5–10 mg 1–4x/day methyltestosteronebmetandren, oreton methyltablet10–30 mg/day buccaltestosteronestrianttablet30 mg 2x/day methyltestosteronebmetandren, oreton methyltablet5–25 mg/day transdermaltestosteroneandrogel, testim, testogelgel25–125 mg/day androderm, andropatch, testopatchnon-scrotal patch2.5–15 mg/day testodermscrotal patch4–6 mg/day axironaxillary solution30–120 mg/day androstanolone (dht)andractimgel100–250 mg/day rectaltestosteronerektandron, testosteronbsuppository40 mg 2–3x/day injection (im or sc)testosteroneandronaq, sterotate, virosteroneaqueous suspension10–50 mg 2–3x/week testosterone propionatebtestovironoil solution10–50 mg 2–3x/week testosterone enanthatedelatestryloil solution50–250 mg 1x/1–4 weeks xyostedauto-injector50–100 mg 1x/week testosterone cypionatedepo-testosteroneoil solution50–250 mg 1x/1–4 weeks testosterone isobutyrateagovirin depotaqueous suspension50–100 mg 1x/1–2 weeks testosterone phenylacetatebperandren, androjectoil solution50–200 mg 1x/3–5 weeks mixed testosterone esterssustanon 100, sustanon 250oil solution50–250 mg 1x/2–4 weeks testosterone undecanoateaveed, nebidooil solution750–1,000 mg 1x/10–14 weeks testosterone buciclatea–aqueous suspension600–1,000 mg 1x/12–20 weeks implanttestosteronetestopelpellet150–1,200 mg/3–6 months notes: men produce about 3 to 11 mg testosterone per day (mean 7 mg/day in young men). footnotes: a = never marketed. b = no longer used and/or no longer marketed. sources: see template. non-medical uses mesterolone has been used for physique- and performance-enhancing purposes by competitive athletes, bodybuilders, and powerlifters. side effects