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Clinical data
AHFS/ International Drug Names
ATC code
Legal status
Legal status
Pharmacokinetic data
Metabolism Liver
CAS Number
PubChem CID
ECHA InfoCard 100.014.397
Chemical and physical data
Formula C20H32O2
Molar mass 304.467 g/mol
3D model (JSmol)
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Mesterolone is a synthetic, orally active anabolic-androgenic steroid (AAS) and derivative of dihydrotestosterone (DHT). It is sold under the brand names Proviron (as Provironum in Asia-Pacific region) and Mestoranum, by Bayer Schering Pharma (earlier by Schering). In the late 1970s and early 1980s, it was used with some success in controlled studies of men suffering from various forms of depression. Mesterolone is a relatively weak androgen and is rarely used for replacement therapies.[1]

Non-medical uses[edit]


Mesterolone had seen widespread use in bodybuilding primarily for antiestrogenic activity in anabolic steroid stacks but such use has declined after introduction of aromatase inhibitors and SERMs. Most significant benefits of current Mesterolone use are considered by bodybuilders to be maintaining libido off-cycle and also relatively and temporarily improving vascularity.[2]

Side effects[edit]


Mesterolone is described as a very poor anabolic agent due to inactivation by 3α-hydroxysteroid dehydrogenase (3α-HSD) in skeletal muscle tissue, similarly to DHT and mestanolone (17α-methyl-DHT).[3] In contrast, testosterone is a very poor substrate for 3α-HSD, and so is not similarly inactivated in skeletal muscle.[3]

Mesterolone is not a substrate for aromatase, and so cannot be converted into an estrogen.[3] As such, it has no propensity for producing estrogenic side effects such as gynecomastia or fluid retention.[3]

Because mesterolone is not 17α-alkylated, it has little or no potential for hepatotoxicity, although its risk of deleterious effects on the cardiovascular system are comparable to those of several other oral steroids.[3]


The C1α methyl group of mesterolone inhibits its hepatic metabolism and thereby confers oral activity, although its oral bioavailability is still low relative to that of 17α-alkylated AAS.[3] In any case, mesterolone is one of the few non-17α-alkylated AAS that is active with oral ingestion.[3]


Mesterolone, also known as 1α-methyl-4,5α-dihydrotestosterone (1α-methyl-DHT) or as 1α-methyl-5α-androstan-17β-ol-3-one, is a synthetic androstane steroid and derivative of DHT.[3] It is specifically DHT with a methyl group at the C1α position.[3]


In one small scale clinical trial of depressed patients, an improvement of symptoms which included anxiety, lack of drive and desire was observed.[4] In patients with dysthymia, unipolar, and bipolar depression significant improvement was observed.[4] In this series of studies, mesterolone lead to a significant decrease in LH and testosterone levels. In another study, 100 mg mesterolone cypionate was administered twice monthly. With regards to plasma T levels, there was no difference between the treated vs untreated group, and baseline LH levels were minimally affected.[5]

See also[edit]


  1. ^ Nieschlag E, Behre HM, Bouchard P, et al. (2004). "Testosterone replacement therapy: current trends and future directions". Hum. Reprod. Update. 10 (5): 409–19. PMID 15297434. doi:10.1093/humupd/dmh035. 
  2. ^ Meso-RX Steroid Profiles - Proviron (Mesterolone)
  3. ^ a b c d e f g h i William Llewellyn (2009). Anabolics. Molecular Nutrition Llc. pp. 19,20,369. ISBN 978-0967930473. 
  4. ^ a b Itil TM, Michael ST, Shapiro DM, Itil KZ (June 1984). "The effects of mesterolone, a male sex hormone in depressed patients (a double blind controlled study)". Methods Find Exp Clin Pharmacol. 6 (6): 331–7. PMID 6431212. 
  5. ^ Kövary PM, Lenau H, Niermann H, Zierden E, Wagner H (May 1977). "Testosterone levels and gonadotrophins in Klinefelter's patients treated with injections of mesterolone cipionate". Arch Dermatol Res. 258 (3): 289–94. PMID 883846. doi:10.1007/bf00561132. 
  6. ^ Brooks, J. R.; Primka, R. L.; Berman, C; Krupa, D. A.; Reynolds, G. F.; Rasmusson, G. H. (1991). "Topical anti-androgenicity of a new 4-azasteroid in the hamster". Steroids. 56 (8): 428–33. PMID 1788861. doi:10.1016/0039-128x(91)90031-p. 

Further reading[edit]