An auto-injector used to administer testosterone enanthate “has a favorable safety profile and is well-tolerated,” according to a new journal of Sexual Medicine study.
The device offers a convenient option for men on testosterone replacement therapy, allowing them to self-administer their medicine at home.
Testosterone is a male sex hormone that gives men their masculine traits. It’s also important for sex drive and erections. When men have a testosterone deficiency, they may feel moody, fatigued, and less interested in sex. For some men, testosterone replacement therapy relieves those symptoms.
Self-injectable testosterone was approved by the U.S. Food and Drug Administration in October 2018 for men whose bodies cannot produce adequate amounts of testosterone on their own. It has not been approved for men whose testosterone levels decline as a normal part of aging.
The study involved 133 men between the ages of 18 and 75 who had testosterone deficiency with symptoms. (Low testosterone, in this case, was diagnosed at levels below 300 ng/dL.)
After learning to use the device, the participants began self-injecting 75 mg of testosterone enanthate once a week. Their goal was to keep their testosterone levels between 350 and 650 ng/dL. Over the study period, doses were adjusted based on individual need, but doses always stayed between 50 and 100 mg.
Periodically during the study, the men underwent ambulatory blood pressure monitoring (ABPM), wearing a special device designed to measure their blood pressure for 24 hours.
For most men, testosterone levels remained at the targeted range. After 26 weeks, 83% of the patients had levels between 300 and 650 ng/dL.
About a quarter of the men had adverse drug reactions, including raised levels of hematocrit (the volume of red blood cells in the blood), hemorrhage at the injection site, bruising, and increases in prostate-specific antigen (PSA) levels. One man had mild pain at the injection site.
Blood pressure monitoring data showed a “small” average increase in the men’s blood pressure over the study period, but none of the men had adverse drug reactions related to blood pressure. In addition, the researchers found no correlation between testosterone and blood pressure.
They noted, however, that for safety reasons, most medical studies of testosterone exclude men with uncontrolled blood pressure. This study followed the same guidelines, so it wasn’t clear whether men who had uncontrolled high blood pressure would have the same results.
“It is for this reason that the prescribing information emphasizes [blood pressure] control before and during use of this product,” the authors wrote.
Overall, they concluded that testosterone delivery with this type of auto-injector was safe and well-tolerated, but they did not know if the results would apply to other forms of testosterone delivery, such as patches and gels.
The Journal of Sexual Medicine
Gittelman, Marc, MD, et al.
“Safety of a New Subcutaneous Testosterone Enanthate Auto-Injector: Results of a 26-Week Study”
(Full-text. Published online: September 21, 2019)
“Self-Injectable Testosterone Now Available”