There is evidence that suggests that androgen might play an important role in different tissues and in modulating sexual response. In women of reproductive age the most important source of androgens present in the blood is the ovary. Androgens complement the contribution of adrenal precursors, which in peripheral organs and target tissue can be transformed into bioactive androgens. The human brain is an important target organ of the sex hormones. The expression in the brain of men and women of estrogenic and/or androgenic receptors (AR) in the cerebral nucleus, especially the hypothalamus, whose important participation in the regulation of the secretion of gonadotrophins, sexual motivation and sexual response is well documented by experimental research on animals and is being verified by studies on functional neuroimaging in humans.The two pivotal studies that have served for acceptance of the testosterone patch as therapy for hypoactive sexual desire by the European Agency for the Evaluation of Medicinal Products (EMEA) have been The Intimate Study (SM1) and The Intimate Study (SM2). The data on the efficiency of these studies have therefore been clear and positive; the side effects have also been studied and were found in general to be the same as those of the placebo group.There are certain limitations in the studies that are currently being evaluated. Studies with androgens alone and androgens plus estrogens in the natural menopause are ongoing at present.