Testosterone is a hormone found in both men and women and is secreted by the adrenal glands, testes, and ovaries. It contributes to muscle mass, strength, endurance, decreased fat, increased exercise tolerance, enhancement of well-being, and psychological status. Testosterone protects against cardiovascular disease, hypertension, body fat, and arthritis. It leads to improved lean muscle mass, increased bone density, decrease in cholesterol, improved skin tone, improved healing capacity, and increased libido and sexual performance. It prolongs the quality of life by decreasing the diseases of aging, as does estrogen in the female. Testosterone is important for everyone making supplementation absolutely recommended for both men and women.