Mesterolone is an androgen and anabolic steroid (AAS) medication which is used mainly in the treatment of low testosterone levels. It has also been used to treat male infertility.
It has also been used to treat delayed puberty in boys. Because it lacks estrogenic effects, mesterolone may be indicated for treating cases of androgen deficiency in which breast tenderness or gynecomastia is also present. The drug is described as a relatively weak androgen with partial activity and is rarely used for the purpose of androgen replacement therapy, but is still widely used in medicine.
Mesterolone has been used for physique- and performance-enhancing purposes by competitive athletes, bodybuilders, and powerlifters.
In one small scale clinical trial of depressed patients, an improvement of symptoms which included anxiety, lack of drive and desire was observed. In patients with dysthymia, unipolar, and bipolar depression significant improvement was observed.
