The 17-alpha isomer of TESTOSTERONE, derived from PREGNENOLONE via the delta5-steroid pathway, and via 5-androstene-3-beta,17-alpha-diol. Epitestosterone acts as an antiandrogen in various target tissues. The ratio between testosterone/epitestosterone is used to monitor anabolic drug abuse.

The 5-beta-reduced isomer of ANDROSTERONE. Etiocholanolone is a major metabolite of TESTOSTERONE and ANDROSTENEDIONE in many mammalian species including humans. It is excreted in the URINE.

Illegitimate use of substances for a desired effect in competitive sports. It includes humans and animals.

The forces and principles of action of matter and energy.

A metabolite of TESTOSTERONE or ANDROSTENEDIONE with a 3-alpha-hydroxyl group and without the double bond. The 3-beta hydroxyl isomer is epiandrosterone.

Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.

A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.

A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.

The unspecified form of the steroid, normally a major metabolite of TESTOSTERONE with androgenic activity. It has been implicated as a regulator of gonadotropin secretion.

These compounds stimulate anabolism and inhibit catabolism. They stimulate the development of muscle mass, strength, and power.