Stanozolol is only found in individuals that have used or taken this drug. Stanozolol has is a synthetic anabolic steroid with therapeutic uses in treating hereditary angioedema. Stanozolol was first synthesized by Clinton et al. in 1959, as a heterocyclic anabolic androgenic steroid. The structure of Stanozolol differs from endogenous steroid hormones and most commercially available anabolic steroids. It most closely resembles methyl testosterone. Instead of the 3-ketogroup in methyltestosterone, there is a pyrazole ring fused to the androstane ring system. This slightly different structure has the disadvantage of making extraction and isolation of the molecule from matrices more difficult. Like most other anabolic steroids, Stanozolol has poor gas chromatographic behavior and is difficult to detect in urine, because of renal clearance and low urinary excretion. This is due to the rapid metabolization, leading to low concentration levels of the parent compound found in urine. Therefore, most research studies had focused on the detection of urinary metabolites. Androgens are drugs, derived from the natural male sex hormone testosterone, with high anabolic potential and minimized androgenic activity. It has been abused by several high profile professional athletes. Stanozolol binds to androgen receptors, such as membrane bound receptor proteins LAGS and stanozolol-binding protein (STBP). Anabolic steroids stimulate protein synthesis, resulting in an acceleration of the food conversion rate and increasing muscle growth, body mass and enhanced performance. Androgens can be used as therapeutics, because they accelerate the recovery of protein deficiency and protein-wasting disorders (e.g. osteoporosis), but they are also widely abused in doping, as well in animals as in men. (PMID: 10404632, 10435307, 11175645, 11284331, 12064656, 12580506, 1448813, 14698206, 15013688, 15458725, 15631866, 15664350, 16040239, 16259046, 16288903, 1640693, 17066372, 17146762, 2306548, 2362445, 2625454, 2663904, 6539197, 9001957, 9300863, 9580049).