The most recent research suggests that between 25 and 40 percent of patients receiving testosterone replacement therapy never had a blood test to measure their testosterone before starting treatment. Preliminary findings by Jacques Baillargeon, director of the epidemiology division in the department of preventive medicine and community health at UTMB, and his colleagues offer clues as to why so many men get testosterone prescriptions without the recommended blood work. According to their analyses of insurance claims databases, about 70 percent of men who have tried testosterone therapy did so after seeing a primary care physician, not a urologist or endocrinologist. Other sources of testosterone include increasingly common low-T clinics, many of which require men to pay for prescriptions out of pocket, prompting Baillargeon to suspect “potentially inappropriate prescribing practices.”