Testosterone is a hormone primarily produced in the testes in men and in smaller amounts in the ovaries in women. It plays a crucial role in developing male physical characteristics, such as increased muscle mass, body hair, and a deeper voice. Testosterone also influences mood, energy levels, and overall health. In addition to its role in physical development, testosterone is important for maintaining bone density and supporting libido in both men and women. Levels of testosterone can fluctuate due to factors like age, stress, and lifestyle, which can impact a person's well-being and vitality.