epitestosterone

Also known as epi-testosterone, 17a-cis-Testosterone, 17-Epitestosterone, cis-Testosterone, Isotestosterone, (1S,2R,10R,11S,14R,15S)-14-hydroxy-2,15-dimethyltetracyclo[8.7.0.0^{2,7}.0^{11,15}]heptadec-6-en-5-one, (10ALPHA,13ALPHA,14BETA,17ALPHA)-17-HYDROXYANDROST-4-EN-3-ONE

Epitestosterone, or isotestosterone, also known as 17α-testosterone or as androst-4-en-17α-ol-3-one, is an endogenous steroid and an epimer of the androgen sex hormone testosterone. It is a weak competitive antagonist of the androgen receptor (AR) and a potent 5α-reductase inhibitor.

Chemical data

Formula: C19H28O2
Molecular weight: 288.4 g/mol
IUPAC name: (8R,9S,10R,13S,14S,17R)-17-hydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-3-one

via PubChem

Drug data · ChEMBL

Molecule type: Small molecule

via ChEMBL · EBI

Research

596 papers

Epitestosterone.The Journal of steroid biochemistry and molecular biology · 2003
Epitestosterone--a hormone or not.Endocrine regulations · 1993
Evaluation of testosterone/epitestosterone ratio influential factors as determined in doping analysis.Journal of analytical toxicology · 2000
Epitestosterone- and testosterone-replacement in immature castrated rats changes main testicular developmental characteristics.Molecular and cellular endocrinology · 2018
5α-reduction of epitestosterone is catalysed by human SRD5A1 and SRD5A2 and increases androgen receptor transactivation.The Journal of steroid biochemistry and molecular biology · 2024

via PubMed

Wikidata facts

Mass: 288.209

Show 3 more facts

chemical formula: C₁₉H₂₈O₂
canonical SMILES: CC12CCC3C(C1CCC2O)CCC4=CC(=O)CCC34C
isomeric SMILES: C[C@]12CC[C@H]3[C@H]([C@@H]1CC[C@H]2O)CCC4=CC(=O)CC[C@]34C

Sources (4)

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Article

6 sections

Contents

Society and culture
Detection of athletic doping
Notable cases
See also
References
External links

Structurally, epitestosterone differs from testosterone only in the configuration at the hydroxy-bearing carbon, C17. Epitestosterone is believed to form in a similar way to testosterone; a 1993 study found that around 50% of epitestosterone production in human males can be ascribed to the testis, although the exact pathway of its formation is still the subject of research. It has been shown to accumulate in mammary cyst fluid and in the prostate. Epitestosterone levels are typically highest in young males; however, by adulthood, most healthy males exhibit a testosterone to epitestosterone ratio (T/E ratio) of about 1:1.