Low testosterone is a condition that affects many males as they continue to age. Testosterone is the male sex hormone produced by the testicles. It works to regulate healthy sexual function and development in males. During puberty, testosterone helps male teens develop facial/body hair, a deeper voice, as well as muscle tone. It is also a necessary hormone in sperm production. As this conditions persists, it can cause issues such as a diminished sex drive, erectile dysfunction, increased levels of fatigue, and reduced lean muscle mass.