ED and Low T: Testosterone Therapy

June is Men’s Health Month. CHP blog posts in June will focus on health care for problems unique to men. Men’s Health Week was designated by an act of the US Congress in 1994 and signed into law by President Bill Clinton. Expanded now to Men’s Health Month, the 30 days of June include Father’s Day and the designated month is to “heighten the awareness of preventable health problems and encourage early detection and treatment of disease among men and boys.”


“ED” and “Low T” have entered the public vocabulary as shorthand for clinical conditions that were formerly the domain of urology and endocrinology medical specialties. As pharmacologic treatments became available, the market was quick to “educate” the public (men) about clinical conditions involving erectile dysfunction, loss of muscle mass, diminished sex drive, and others that formerly were the topics of discussions between men and their physicians.

In 1998 Pfizer, the maker of Viagra, hired former Senator and presidential contender, Bob Dole, as a spokesperson to promote the drug. “ED” firmly entered American’s vocabulary. With increased direct to consumer advertising, the failure of men to “perform in the bedroom” became a rich market to pursue. Since then, sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra) and their generic equivalents have become a significant piece of the market place.

More recently, “men’s health” has become focused on a wider variety of things that men notice, like loss of muscle mass, declining energy, aches, and pains that extend beyond concerns that emerge in the “bedroom.” While these symptoms are common and expected as men grow older, it has not slowed the rapidly expanding “medicalization” of normal aging. “Low T” is now the topic of public discussion in the media and a source of an overload of personal anecdotes. Male menopause and late-onset hypogonadism have joined low T as popular diagnostic shorthand, the solutions for which testosterone medication and non-prescription “natural” treatments are marketed. But what does the evidence tell us about Low T.

The hormone testosterone occurs naturally in both men and women. The effects of the hormone in males begin early in gestation and proceeds throughout life affecting the development of typical male characteristics like facial hair, muscle mass, sex drive, and behavior (competitiveness, aggression). Testosterone levels in men peak in early adulthood and gradually decline, about 1% a year past age 30. And with this decline other typical features of aging (e.g. wrinkles, arthritis, grey hair) combine and have been linked to “Low T.” However, differentiating normal changes of aging from effects specific to low levels of testosterone is clinically challenging. While these changes occur as age increases, there is little evidence that declining testosterone levels cause the other declines of aging in men.

These complex and uncertain clinical correlations however have not slowed the marketing successes of various Low T treatments. Prescriptions for testosterone drugs have tripled over the past few years. Specialty clinics focused on low T have proliferated. The drugs are available widely over the internet. The nutritional supplement and natural medicine industries have flourished.

Testosterone replacement therapy (TRT) is applied in oral, dermal, and injectable formulations. In cases of a clear-cut clinical presentation and laboratory-confirmed abnormally low levels of the hormone, medication has real value. Testosterone deficiency due to genetic anomalies such a Klinefelter Syndrome, toxicity from chemotherapy, injury, and disorders of testicular development like undescended testis clearly can benefit from careful diagnosis and therapeutic interventions.

However, it has been estimated that upward of 25% of testosterone prescriptions have been made without testing the level of testosterone beforehand, half of men taking testosterone do not have regular follow-up assessments of hormone levels, and about 1/3 of men receiving medications do not meet accepted clinical criteria for testosterone deficiency. This suggests that a significant number of men using these drugs are doing so inappropriately.

Testosterone medication is not without risk of adverse effects. Some side effects are fairly benign such as hair loss and acne, while others have much more dire consequences. Hypertension, elevated cholesterol, increased risk of cardiovascular disease, behavioral changes such as anxiety, aggression, hostility, and depression have all been associated with drug treatment.

The evidence supporting TRT for the conditions for which it is most heavily promoted (ED, loss of virility, declining muscle mass, etc.) is contradictory and weak. Most clinical studies are within men who have confirmed low testosterone. In those men, TRT “may” improve sexual function. It has not been studied among those diagnosed with “Low T” in typical Low T clinics. TRT has not demonstrated improvement in sexual satisfaction and may only “slightly” improve sexual function in men over 65. TRT does increase muscle mass in otherwise healthy (i.e. normal testosterone level) subjects.

The most robust clinical trial evidence is from the National Institutes of Health-sponsored Testosterone Trials. Study participants were all over 65. The primary outcomes measured were related to sexual function, physical function, and vitality. The results show that TRT did help some patients. However, TRT is not a panacea for older men.

Non-prescription treatments include a wide range of nutraceutical and other interventions. Promoted by the likes of Dr. Oz and Dr. Weil as well as countless nutrition practitioners, evidence supporting these treatments is generally sparse. Two supplements (acetyl-L-carnitine and propionyl-L-carnitine) may have results similar to that of TRT.

While some TRTs are outside the scope of practice for some IH clinicians, the subject is so topical that it can come up in any clinical setting where IH is practiced. Knowing the evidence about pharmacologic and natural treatments may help IH clinicians to better inform their patients.