There is an advertising frenzy in the US in marketing of testosterone supplements…a multi-billion dollar business. To observers outside the US it must seem that all American men have Low T and suffer from sexual dysfunction, low energy, brittle bones, depression and obesity. Well, the obese part has some truth….the Centers for Disease Control tell us that more than 35% of US adults are obese with medical costs related to obesity amounting to over 147 billion dollars….more on this in a bit. No doubt about it, low serum testosterone also referred to as Low T, Hypogonadism and Andropause, is a real entity affecting over 40% of men 40 years and older. In fact, as men age the incidence of low testosterone goes up. The real issue however is: who should be treated? Men with breast cancer (yes men, although rare, do get breast cancer too) and those men with diagnosed, but not yet treated, prostate cancer should definitely not take testosterone supplements. To this group, I would add those men interested in maintaining their fertility (or ability to conceive a child) since testosterone and androsterone (collectively called androgens) will significantly decrease, or completely stop, sperm production. In fact, 10 to 20% of these men might not re-start sperm production after stopping testosterone therapy. In addition, many of the men that had been placed on testosterone therapy will not return to their pre-therapy production of sperm! So who might benefit from testosterone therapy? Well-respected professional societies, such as the American Urological Association, American Society for Andrology, American Society for Reproductive Medicine and the Endocrine Society, offer guidelines on who should receive testosterone supplementation. In my practice, as a Urologist specializing in male reproduction and sexual medicine, I consider treatment in men with a low serum testosterone level and at least one symptom of low testosterone that significantly affects the patient’s quality of life. Also, men with a decreased bone density and a low serum testosterone may benefit from supplementation. For men interested in fertility, non-testosterone options exist that will raise their testosterone and preserve, and possibly increase, their sperm production. …and yes, overweight men often do have a low testosterone. However, the best way to treat them is by lifestyle changes, not supplementation. By that, I am indeed referring to diet and exercise, leading to an improvement in serum testosterone by 15% in one recent study!