Methyltestosterone is an anabolic steroid hormone used to treat men with a testosterone deficiency. It is also used in women to treat breast cancer, breast pain, swelling due to pregnancy, and with the addition of estrogen it can treat symptoms of menopause. The effects of testosterone in humans and other vertebrates occur by way of two main mechanisms: by activation of the androgen receptor (directly or as DHT), and by conversion to estradiol and activation of certain estrogen receptors. Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5α-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5α-reductase. DHT binds to the same androgen receptor even more strongly than T, so that its androgenic potency is about 2.5 times that of T. The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing the androgen effects. Methyltestosterone is marketed under the brand names Android, Androral, Metandren, Oraviron, Testred, Virilon.

Mestanolone is an oral analogue of dihydrotestosterone. This steroid is a 17-alpha methylated form of this potent endogenous androgen, being essentially (in structure) to dihydrotestosterone what methyltestosterone is to testosterone. Overall, mestanolone has an activity profile not very dissimilar from the hormone it is derived from. Like dihydrotestosterone, mestanolone is primarily androgenic in nature, displaying a low level of anabolic activity. Both dihydrotestosterone and mestanolone are also devoid of estrogenic activity. Dihydrotestosterone was synthesized in 1935. After that 17-alpha-methylated version also appeared. This steroid was not frequently used in clinical medicine. It was produced under the name of ermalon for short period of time. Most studies involving mestanolone were carried out in the 1950s and 1960s. In the 1970s and 1980s it was used as part of the East German doping machine. Mestanolone was evaluated not for its anabolic ability but for its androgenic essence. It improved the functioning of the CNS and neuromuscular interaction. Athletes claimed that it did not make them huge, but gave them speed, strength, aggression, stamina and resistance to stress. Mestanolone is still valued as an oral androgen.