Testosterone propionate is a steroid hormone from the androgen group. In mammals, testosterone is primarily secreted in the testicles of men and in female eggs, but small amounts are also secreted by the adrenal glands. It is the main male sexual hormone and an anabolic steroid. In both men and women, testosterone plays an important role in health and well-being as well as sexual functions. Examples include increased libido, increased energy, increased production of red blood cells, and protection against osteoporosis. On average an adult human body produces approximately 40-60 times more testosterone from an adult female body, but women are more susceptible to hormone.