More than 95 percent of all hair thinning in men and women is due to a condition known as androgenic alopecia, or male pattern baldness. This condition is due to a by-product of testosterone known as DHT, which is produced in high quantities by the 5-alpha-reductase enzyme found in the scalp. The binding of DHT to the genetically predisposed hair follicle results in gradual suppression and miniaturization of the hair and eventual shrinkage and deterioration of the hair follicle.