The primary male hormone (androgen) is testosterone, which is produced in the testes, ovaries and adrenal glands. In men, testosterone plays a key role in the development of male reproductive tissues such as the testis and prostate as well as promoting secondary sexual characteristics such as increased muscle, bone mass and the growth of body-hair. In addition, testosterone is essential for health and well-being as well as for the prevention of osteoporosis.
Male hypogonadism is the medical term referring to the decreased functional activity of the testes, leading to low testosterone levels. The position of the American Society of Andrology is that "Testosterone replacement therapy in aging men is indicated when both clinical symptoms and signs suggestive of androgen deficiency and decreased testosterone levels are present." Clinical syndromes include fewer erections, fatigue, thinning skin, declining muscle mass and strength, more body fat, etc.
Testosterone Replacement Therapy can take the form of depot injections, transdermal patches, gels, subcutaneous pellets and tablets.
In 1935, the laboratories of Organon were the first to isolate a hormone from human testicles and they named the hormone 'Testosterone'.
Testosterone esters provide a sustained release of testosterone from the injection depot into the blood plasma. Different testosterone esters provide for different half lives. Providing a mixture of various testosterone esters will lead to rather stable serum testosterone level over time.
Male HRT is also used for men who have lost their testicular function following disease (e.g. cancer) or due to other causes.
- Dihydrotestosterone (Androstanolone, Stanolone)
- Testosterone cyclopentylpropionate
- Testosterone decanoate
- Testosterone isocaproate
- Testosterone phenylpropionate
- Testosterone propionate
- Testosterone undecanoate