How common is testosterone deficiency?

Research has confirmed that testosterone counts in men are significantly lower than they were just a few decades ago. One in four men over the age of 30 may have abnormally low testosterone levels according to scientific studies.*

Around the age of 30 testosterone levels naturally begin to decline, but it's usually a very gradual process. For most men, testosterone levels drop between one to two percent each year from the age of 35. Free testosterone levels also drop considerably as men age, making TD even more common. An increase in obesity, hormone-disrupting environmental chemicals, and anabolic steroid use is also making testosterone deficiency in younger men more prevalent than ever.

*The Journal of Clinical Endocrinology & Metabolism