The male hormone (androgen) testosterone is most often associated with sex drive and plays a vital role in sperm production. It also affects bone and muscle mass, the way men store fat in the body, and red blood cell production. While testosterone replacement treatment is valid for genuinely low testosterone levels (“hypogonadism”), it cannot be counted on to improve mood, memory, and sex drive by older men looking for a “youth prescription.” While androgen replacement therapy more than tripled among men aged 40 years and older between 2001 and 2011, testosterone prescriptions for U.S. men aged 30 years and older decreased by 48 percent overall from 2013 to 2016 due to concerns over elevated risk of heart attack and stroke.
P.S. While a 2018 study found that one year of androgen replacement therapy helped men aged 72 years and older to improve their sexual function, it also led to increased coronary artery plaque levels and higher PSA (prostate-specific-antigen) levels.