Male Birth Control Update

Male Birth Control Update
Deandra Lundeen, PharmD, Park Nicollet

A medication for male hormonal contraception has been talked about for many years. Yet, a male birth control pill has not joined the market despite research in this area since the 1970s. Researchers have looked at various formulations such as hormonal pills, injections, gel formulations, and nonsurgical vasectomies. All of these still require extensive studies and trials conducted in humans. In the past, research was conducted investigating testosterone as a form of contraception which was found to be highly effective at decreasing sperm levels, but only in high doses. This was promising until unfavorable side effects were reported which included weight gain, mood swings, and acne. At this time, there are only two forms of approved male birth control available: vasectomies and male condoms.

A recent animal study conducted by the University of Minnesota evaluated a non-hormonal male contraceptive (YCT529) that substantially reduced sperm counts in male mice. During the four week study period, it was 99% effective in preventing pregnancy and no apparent side effects were seen. They found after discontinuation of the contraceptive that mice could impregnate a female mouse four to six weeks later. The researchers looked to develop a non-hormonal contraceptive because most male birth control compounds previously studied targeted testosterone. The most recent trials utilizing testosterone have used a combination of physiological testosterone doses and progestin which demonstrates suppression of gonadotropins and sperm concentration. This has been shown to be safer and much more tolerable compared to previous studies that used supraphysiological doses of testosterone. The side effects of the hormones still remain to be one of the biggest challenges that hinders progress in this field. 

The new compound, YCT529, targets a protein in the body called retinoic acid receptor alpha (RAR-α) which is part of the receptor that binds retinoic acid. Retinoic acid plays a key role in embryonic development and sperm formation. With the removal of RAR-α, mice became sterile. Although these results are promising, it is important to keep in mind that there are many differences between human and mice reproductive systems. The hope is for clinical trials to begin by the end of 2022 to determine efficacy in humans. The researchers at the University of Minnesota are hopeful that even if trials for this compound are unsuccessful, there is now a starting compound to investigate other male contraceptive options in the future.

Although there has been success in mice in this study, a male birth control pill likely will not come to market for another 10 years. With that said, scientists at the University of Minnesota appear to be playing a key role in advancing reproductive health medicine.

References:

  1. Blum D. Despite encouraging research, a male birth control pill remains elusive. The New York Times, Published March 25, 2022. Accessed May 10, 2022. https://www.nytimes.com/2022/03/25/well/male-birth-control-pills.html.
  2. Docto I. Human trials for a male birth control pill could start later this year. DH News, Published March 25, 2022. Accessed May 10, 2022. https://dailyhive.com/vancouver/male-birth-control-human-trials.
  3. Thirumalai A, Page ST. Male hormonal contraception. Annu Rev Med. 2020;71:17-31. doi:10.1146/annurev-med-042418-010947.