Advertisements claim testosterone supplements can improve libido and energy levels for aging men. While it is true that testosterone levels drop as part of the normal aging process, the need for supplements is not clear. Experts are not even sure if the normal testosterone drop is good or bad. In addition, normal levels are difficult to determine because testosterone is different during stress, exercise, and time of day.
A recent study in the Journal of the American Medical Association , reports that oral testosterone supplementation does not improve muscle strength, overall physical ability, intellectual function, bone mineral density, or quality of life in healthy men aged 60-80 years.
About the Study
The researchers studied the effects of testosterone therapy in a trial of 237 healthy men aged 60-80 years. The men were divided into two groups. One group received testosterone undecenoate 80 mg tablets, while the second group received a placebo (fake pill). Both groups took their pill twice daily for six months.
The men underwent many tests to determine the effect of the medication:
- Overall physical ability was tested with a timed get up and go test, and hand and leg strength tests.
- Intellectual ability was tested on eight different instruments.
- Bone mineral density of the hip and lumbar spine (low back) was performed with a dual-energy x-ray absorptiometry scan .
- Body fat and lean tissue percentages were determined with a total body dual-energy x-ray absorptiometry and abdominal ultrasound of fat mass.
- Quality of life was assessed with a survey.
- Metabolic risk factors were assessed with blood tests for cholesterol, blood sugar, and insulin.
- Prostate health was assessed with serum prostate-specific antigen level, ultrasonographic prostate volume, and international prostate symptom score.
- Overall safety of the medication was followed with blood tests for liver and kidney function.
- After 207 men (87% of total) completed the trial there was no significant differences between testosterone and placebo groups in muscle strength and physical ability, intellectual function, bone mineral density, and quality of life. However, the testosterone group had increased lean body mass, decreased fat mass, and improved insulin sensitivity. Unfortunately, the testosterone group also had worsening of factors related to heart disease risk: decreased high-density lipoprotein cholesterol (good cholesterol), increased blood pressure, and increased incidence of metabolic syndrome . There were no adverse effects on the prostate detected by this study.
How Does This Affect You?
Testosterone therapy is definitely recommended for patients with congenital or acquired primary hypogonadism (the testicles fail to produce testosterone). This study was specifically looking for effects of testosterone therapy in healthy men with low but still active testosterone production.
There are many studies with contradictory results regarding quality of life and safety of testosterone supplementation in healthy men. Those that discourage testosterone use in healthy men are concerned over the effect on prostate and prostate cancer which has not been studied enough. While this study revealed no prostate problems from testosterone, the participants did have some worsening of risk factors for heart disease including worsened cholesterol profiles and increased blood pressure. This study reinforces the importance of checking with your doctor before taking any medication or supplement.
- Reviewer: Larissa J. Lucas, MD
- Review Date: 02/2008 -