Testosterone (C₁₉H₂₈O₂) — Properties, Uses & Safety

Overview

Testosterone (C19H28O2) is the primary male sex hormone and an anabolic steroid with a molar mass of 288.43 g/mol. Its complex IUPAC name reflects its tetracyclic steroid structure: four fused carbon rings (three six-membered cyclohexane rings and one five-membered cyclopentane ring) forming the characteristic steroid skeleton, with a ketone group at C-3 and a hydroxyl group at C-17. At standard conditions, testosterone is a white crystalline solid. In the human body, testosterone is produced primarily in the testes in males and in smaller amounts in the ovaries and adrenal glands in females. It is essential for male sexual development during puberty (deepening of voice, growth of facial and body hair, muscle development), maintenance of bone density, red blood cell production, and regulation of mood and energy levels. Testosterone also plays important roles in female physiology, contributing to bone strength, muscle mass, and libido. The GHS hazard code H361 (suspected of damaging fertility or the unborn child) reflects its potent hormonal activity. Synthetic testosterone and its derivatives (anabolic steroids) are used medically for hormone replacement therapy but are also misused in sports to enhance muscle growth and athletic performance — a practice banned by virtually all sports organizations due to health risks including liver damage, cardiovascular problems, and hormonal imbalances. For chemistry students, testosterone is an excellent example of steroid biochemistry and the relationship between molecular structure and biological function. Its multiple chiral centers (six stereocenters) make it a compelling case study in stereochemistry — only one specific stereoisomer is biologically active. Testosterone illustrates how small structural changes to the steroid skeleton can dramatically alter biological activity, connecting to medicinal chemistry and drug design. The biosynthesis of testosterone from cholesterol demonstrates multi-step enzymatic transformations and the importance of functional group chemistry in biological systems.

IUPAC Name

(8R,9S,10R,13S,14S,17S)-17-hydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-3-one

CAS Number

58-22-0

PubChem CID

6013

Molecular Formula

C₁₉H₂₈O₂

Molar Mass

288.431 g/mol

State at STP

solid

Appearance

White crystalline solid