A new hormone skin gel shows promise in providing a birth control method to be used by men. Preliminary research showed that applying both testosterone and progestin gel to the skin significantly lowered the sperm counts in men tested.
The results of the study were presented at The Endocrine Society's 94th Annual Meeting in Houston.
Principal investigator Christine Wang, MD, professor at Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center reported to Science Daily that "This is the first time that testosterone and Nestorone (synthetic progestin) have been applied to the skin together to deliver adequate amounts of hormones that suppress sperm production."
In this study, 99 men were divided into three groups and instructed to apply one of three unidentified transdermal gels every day for six months.
Group One had a gel that only contained 10 gms of testosterone plus a dummy gel of no progestin. Group Two used one with 10 gms of testosterone and one with 8 mg of Nestorone, a gel-based contraceptive. Group Three used one with 10 gms of testosterone and one with 12 mg of Nestorone.
Wang reported to Healthday News that the gel was applied in two spots. The testosterone component went on the arm and the progestin component was applied on the abdomen.
“Both testosterone and progestin work together to turn off production of reproductive hormones controlling the production of sperm,” according to Wang. In previous studies, progestin was delivered using pills, injections and implants
Fifty-six men completed at least 20 weeks of the study.
“Up to 89 percent of the men who received the combination formulas saw their sperm concentrations plunge to less than 1 million sperm per milliliter, versus just 23 percent of those receiving only testosterone,” according to HealthDay.com.
“Normal sperm concentration is more than 15 million sperm per milliliter.”
Approximately 78 percent of men in the 8 mg Nesteron group and 69 in the 12 mg Nestorone group had their sperm counts drop so significantly that no sperm could be detected.
Only 23 percent in the testosterone only group had this occur, according to EurekAlert.