Developing an universally effective male contraceptive has indeed proven challenging. While female oral contraception is designed to suppress ovulation, mimicking the natural process accompanying pregnancy or lactation, no comparable natural period of infertility exists in male physiology that researchers can seek to replicate. Using the efficacy of female methods as a benchmark for male contraception is legitimate, especially when considering which method would appeal to couples choosing from the whole spectrum of available options. However, another legitimate efficacy end point would be to compare hormonal methods to condoms, the only other reversible male method. In trials where male hormonal contraception was used as a sole means of pregnancy prevention, all subjects in four trials were suppressed to below a threshold of 1–5 million sperm/ml resulting in pregnancy prevention of over 95%, even in those who were incompletely suppressed.[5,19,20] This efficacy is a great improvement over the 12% failure rate of condoms and is close to the first-year failure rate of oral contraceptive pills (3%). Racial differences in efficacy are often characterized as a major obstacle in developing a male hormonal method. Consistent product responses would lead to simpler dosing algorithms and fewer physician visits to get patients established on regimens. However, the variations in response could be exploited through the development of regional formulations. In Asia, where population density and growth rates are high, men are extremely responsive to low, physiologic doses of testosterone, suggesting a potential market for a regionally formulated product.
Expert Rev Pharmacoeconomics Outcomes Res. 2012;12(5):605-613. © 2012 Expert Reviews Ltd.