New male contraceptive methods are closer than they have been before. Progress in developing new reversible male contraception has been slow – research originally began at roughly the same time as female contraceptive research in the 1950s but did not enjoy the same success and investment as female contraceptives.
Various publicly funded initiatives have led to important developments in male reproductive control, particularly the no-scalpel vasectomy technique, a highly effective permanent contraceptive method. Several new testosterone esters, such as testosterone undecanoate, also have contraceptive potential. Unfortunately, while the hormonal approach has been clearly shown to be capable of providing effective and reversible contraception, there remains no product available.
Currently, the Eunice Kennedy Shriver National Institute for Child Health and Human Development in partnership with the Population Council, are coordinating a multicentre trial of a self-administered gel combination of testosterone and the progestogen Nestoroneâ. This user-initiated daily use method compliments the predominately injectable male contraceptive methods previously investigated.
Aside from testosterone-progestogen combination treatments, novel long-acting steroids with both androgenic and progestogenic activity are in early clinical trials. These synthetic steroids have a similar effect as testosterone-progestogen hormonal contraceptives but allow the possibility for once daily oral dosing or subdermal implants, broadening the contraceptive options for men.
New non-hormonal approaches that may offer advantages. Interventions with potential sites of action on spermatogenesis, sperm maturation in the epididymis or at the vas are all in preclinical testing at present.
54% of women in the UK already rely on their male partner for contraception, whether male sterilisation, male condom or withdrawal method. Since 2000, there have been several survey-based studies across a variety of cultural and social settings indicating that at least 25% of men would consider hormonal contraception acceptable.
Regrettably, they continue to lack that opportunity but new options will hopefully come to market in the next few years.