Introduction

Contraception is critical to health, development, and quality of life. In wealthy countries, the contraceptive revolution of the past century has allowed couples to plan their families and safely space births. This has set in motion a chain reaction: maternal mortality has fallen, educational opportunities have increased, and both men and women have gained the freedom to participate in, and contribute to, the world outside the home. Yet for many men and women in wealthy countries, this revolution remains unfinished; and for even more men and women around the world, the revolution has never arrived.

At first glance, it would seem that there are plenty of contraceptive choices: Contraceptive Technology, the bible of the field, lists at least 20. However, many of these methods are too expensive for most of the world’s couples, and few methods are both effective and free from side effects.

For this reason, policymakers try to provide a "contraceptive supermarket” for women, hoping that if a variety of methods is available, each woman will be able to select the method that best meets her needs. Every method has advantages and disadvantages. For example, the contraceptive sponge is on the market even though it should be used with a backup method; the contraceptive Pill is available even though it can cause circulatory problems; and the contraceptive patch was developed even though it doesn’t protect against sexually transmitted infections. Every other method has drawbacks as well: diaphragms are messy and can bring on urinary tract infections; copper IUDs often cause cramping and heavier bleeding; progestin methods can cause mood disturbances; cervical caps have a high failure rate; and so on.

Men’s options are even less satisfactory: not only are they imperfect, but there are fewer of them. Other than withdrawal, which leads to a 27% pregnancy rate in real-world use, men have only two contraceptives to choose from: vasectomy (male sterilization) and the condom. Neither is ideal. Vasectomy is permanent, and condoms reduce sensation for both partners and have relatively high pregnancy rates in typical use. Yet men who want control over their reproduction, or who want to relieve their partner of the contraceptive burden, have no other choices.

Fortunately, several other male contraceptives are under development that would present very attractive alternatives for men. These methods have received scant attention in the mainstream biomedical research community. Because they are not well-known, most people who learn of these methods assume that they must be backed by limited data. However, this is not the case. After more than 80 years of research in France, China, India, Australia, and the United States, an impressive body of evidence supporting these methods has begun to accumulate. One method has even been through extensive animal studies and provided more than a decade of contraception to the first wave of several dozen volunteer test subjects — as well as several years (and counting) of contraception for the subsequent wave of some 140 subjects.

More than a decade ago, the Male Contraception Information Project’s paper “Frontiers in Nonhormonal Male Contraception: A Call for Research” first introduced some of these methods to the public. Since then, scientific advances have produced multiple new leads that are close to being tested in humans.

The dedication of many researchers, plus a greater societal openness to the subject, mean that men have more to look forward to (and advocate for) than ever before. However, the best of the methods also happen to be the least profitable, so it is likely that only with government support will they be brought to market. Public advocacy is essential to creating and sustaining that support.

This paper reviews the need for a good new male contraceptive, details the substantial progress of the past decade, and identifies the most promising areas of research. It is intended to be a comprehensive, fully referenced resource for those who wish to write about nonhormonal male contraception. (To read about  hormonal male contraception research, click here.)

Developing a nonhormonal male contraceptive is well within our ability as a society. The technical challenges are not complex. No breakthrough is required: only the dedication, commitment, and money to finish taking the first steps on the promising methods that already exist. The task is small — and yet the public health rewards of developing a long-term male contraceptive would be huge.

Next section: Why do we need new contraceptives?