Review Article

Development of a transdermal gel for reversible male contraception

The global unintended pregnancy rate is about 50% of all pregnancies worldwide, and it is even higher among adolescents in the United States [1], [2]. At present, the responsibility of preventing unintended pregnancies falls almost entirely on women. Contraceptive choices for men are limited and lacking, with condoms and withdrawal that have high failure rates, and vasectomy, meant to be a permanent method and not reliably reversible. Having such limited options prevents men from having sufficient contraceptive options to support their own reproductive health needs, while also preventing them from taking a more active role in contraceptive responsibility within relationships.

Even though there is a glaring unmet need for more methods of male contraception, support and funding for research and development has been limited. Most funding for the development of male contraceptives has come from not-for-profit or government organizations conducting research in male contraception and this field has struggled with limited funding over the past decades. The lack of involvement from industry, until recently, may be related to questions that men may not be willing to use a male method, will their partners trust them, who would provide men with the method, and will new methods compete with existing female methods? However, a large survey intended to measure consumer demand for novel male contraceptives and identify product attributes associated with men's preferences, showed that 61% of men had interest in trying novel male contraceptives in their first year of availability, ranging from 39% and 49% (pre- and post-the landmark Dobbs v Jackson Supreme Court decision reversing nation-wide protection of abortion) in the United States to 76% in Nigeria and Bangladesh [3]. Their female partners' interest and trust in male contraceptive use was also very high across all regions. This survey reveals strong demand for novel male contraceptives from developing regions compared to the United States, highlighting the potential market for novel male methods to meet unmet needs, and female partners' trust in men to use them. Men across all countries prefer less invasive forms of contraceptive administration and the transdermal gel was rated among the first preferences in most countries where the survey was conducted. A Liqui-Patch® formulation was also rated favorably, whereas long-acting injectables or implants were not favored by men from medium to low-income countries.

Reversible male hormonal contraception has been undergoing clinical evaluation for around 50 years [4]. Various injections and implants have been tested by over 2,000 couples worldwide, with all studies demonstrating reversibility [5] and around 95% effectiveness in preventing pregnancy when men reach appropriate sperm thresholds (below one million sperm/ml) [6], [7]. These rates are comparable to the typical use rates for the female pill and are better than condoms.