Advances in Male Contraception: When Will the Novel Male Contraception be Available?

Abstract

Many contraceptive methods have been developed over the years due to high demand. However, female contraceptive pills and devices do not work for all females due to health conditions and side effects. Also, the number of males who want to actively participate in family planning is gradually increasing. However, the only contraceptive options currently available to males are condoms and vasectomy. Therefore, many male contraceptive methods, including medication (hormonal and non-hormonal therapy) and mechanical methods, are under development. Reversibility, safety, persistence, degree of invasion, promptness, and the suppression of anti-sperm antibody formation are essential factors in the development of male contraceptive methods. In this paper, male contraceptive methods under development are reviewed according to those essential factors. Furthermore, the timeline for the availability of a new male contraception is discussed.

Keywords: Azoospermia; Contraception; Contraceptive agents; Drug development; Spermatogenesis; Sterilization.

Fig. 1. Percentage distribution of contraception used globally by females of reproductive age (15–49 years) in 2019. Caption: Percentage distribution of contraceptive methods (Left), percentage distribution of male contraceptive methods (Right). The withdrawal method is unreliable for contraception due to its high failure rate. Therefore, it is difficult to consider it as an actual contraceptive option for males.

Fig. 2. Male contraception options that are currently available or in development. (A) Hypothalamic-pituitary-testicular axis feedback control process through exogenous administration of androgens and progestins in hormonal contraception, (B) various contraceptive methods targeting the vas deferens, (C) extra-body control of fertility using heat or ultrasound, (D) various non-hormonal contraceptive drugs that affect fertilization after spermatogenesis and maturation, (E) male condom. FSH: follicle stimulating hormone, LH: luteinizing hormone, GnRH: gonadotropin-releasing hormone.

Fig. 3. Research duration and stage of male contraceptive methods currently under development. Bars represent the period since the concept was first presented for each method in development. “Hormonal methods” refers to male-targeted hormonal methods only. RISUG and hormonal methods, which are in phase 3 clinical trials, are the male contraceptive methods closest to commercialization. RISUG: reversible inhibition of sperm under guidance, TSSK: testis-specific serine/threonine kinase.