Andropause, also known as male androgen deficiency syndrome, is the male equivalent of female menopause. It results from diminished levels of testosterone in the body, and exhibits a similar symptom complex to female menopause. Testosterone is a hormone secreted by the ovaries, adrenal glands and testes. It is the primary male sex hormone, responsible for male sexual development and critical in maintaining erectile function, libido, normal energy levels, and mood. Testosterone also controls a whole range of physiological functions throughout the body.