Nandrolone: C18 steroid with androgenic and anabolic properties. It is generally prepared from alkyl ethers of ESTRADIOL to resemble TESTOSTERONE but less one carbon at the 19 position.Anabolic Agents: These compounds stimulate anabolism and inhibit catabolism. They stimulate the development of muscle mass, strength, and power.Estranes: A group of compounds forming the nucleus of the estrogenic steroid family.Doping in Sports: Illegitimate use of substances for a desired effect in competitive sports. It includes humans and animals.Androstenediols: Unsaturated androstane derivatives which are substituted with two hydroxy groups in any position in the ring system.Methandrostenolone: A synthetic steroid with anabolic properties that are more pronounced than its androgenic effects. It has little progestational activity. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1188)Methyltestosterone: A synthetic hormone used for androgen replacement therapy and as an hormonal antineoplastic agent (ANTINEOPLASTIC AGENTS, HORMONAL).Ethylestrenol: An anabolic steroid with some progestational activity and little androgenic effect.Lynestrenol: A synthetic progestational hormone used often in mixtures with estrogens as an oral contraceptive.Pharmaceutical Vehicles: A carrier or inert medium used as a solvent (or diluent) in which the medicinally active agent is formulated and or administered. (Dictionary of Pharmacy, 1986)Substance Abuse Detection: Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.Gas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.Testosterone: 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.