On March 3, 2015, the U.S. Food and Drug Administration (FDA) announced that new labeling requirements for FDA-approved testosterone products.
Manufacturers must now clarify the approved uses of testosterone and note the possibility of cardiovascular risks.
The FDA has approved testosterone for the treatment of hypogonadism – low testosterone caused by medical conditions. For example, if men’s testes do not function properly, they might not produce adequate amounts of testosterone. Problems in the pituitary gland or other parts of the brain that trigger testosterone production may also result in hypogonadism.
However, testosterone levels also likely decline with age and are often associated with fatigue, depression, weakness, and low sex drive. Some physicians prescribe testosterone therapy to treat these symptoms.
This concerns some experts, as testosterone is not approved for age-related hormonal declines. More research on the safety and efficacy is needed, they say.
Cardiovascular risks are another concern. Studies on this subject have had controversial and mixed results.
Within the past 18 months, studies in the Journal of the American Medical Association (JAMA) and PLOS One reported increased cardiovascular risks for men on testosterone therapy.
The reliability of these studies has been widely questioned, as concerns related to statistical errors and methodological problems have been raised. In January 2014, the FDA said it would further investigate the safety of testosterone products.
In the meantime, members of the Androgen Study Group analyzed dozens of studies involving testosterone and cardiovascular risk. They published their findings online in January in Mayo Clinic Proceedings.
Only four of the studies they reviewed showed increased cardiovascular risk for men on testosterone therapy. Two were the papers noted above.
In contrast, many of the other studies showed a “beneficial effect of normal [testosterone] levels on [cardiovascular] risks and mortality.”
The authors also found associations between testosterone therapy and reduced obesity, fat mass, and waist circumference, as well as better glycemic control.
On the other hand, low testosterone was linked to atherosclerosis, coronary artery disease, and deaths from cardiovascular disease.
“In summary, there is no convincing evidence of increased [cardiovascular] risks with [testosterone] therapy. On the contrary, there appears to be a strong beneficial relationship between normal [testosterone] and [cardiovascular] health that has not yet been widely appreciated,” they wrote.
The FDA will also require makers of testosterone products to conduct further research on cardiovascular risk.
Mayo Clinic Proceedings
Morgentaler, Abraham MD, et al.
“Testosterone Therapy and Cardiovascular Risk: Advances and Controversies”
(Full-text. Published online: January 26, 2015)
“Review Finds No Evidence of Testosterone Harm”
(January 30, 2015)
“FDA: Testosterone Replacement Tx Review Prompts New Warnings, Updated Labeling”
(March 3, 2015)
U.S. Food and Drug Administration
“FDA Drug Safety Communication: FDA cautions about using testosterone products for low testosterone due to aging; requires labeling change to inform of possible increased risk of heart attack and stroke with use”
(March 3, 2015)