Chemical Powders

4-Hydroxytestosterone is testosterone substituted with a hydroxy group on the fourth carbon atom. It is an anabolic steroid with no therapeutic indications, which is prohibited from use in sports by the World Anti-Doping Agency. 1

Formestane (Lentaron) acts as a prohormone of 4-Hydroxytestosterone, as 4-Hydroxytestosterone is one of the many byproducts of formestane metabolism. It is specifically the 17-hydroxylated analog to formestane. 1 Like formestane, 4-hydroxytesterone has been patented for use in decreasing estrogen production in the body, but no such indication currently exists. 4-Hydroxytestosterone was first patented in 1955 by G.D Searle & Company.

4-hydroxytestosterone is a fat soluble compound which can cross the lipid bilayers of cell membranes to enter the cytoplasm of cells. In the cytoplasm, 4-hydroxytestosterone can bind to an androgen receptor, which then gets transported to the nucleus of the cell to alter protein transcription and translation. Ananolic steroids are believed to increase muscle mass by increasing the production of proteins, as well as by reducing the effects of the stress hormone cortisol, which is known to promote muscle breakdown. It is postulated that other steroid hormones (glucocorticoids) may also be inhibited by anabolic steroids in order to prevent muscle catabolism.