Four pills, two jabs and a gel ... the long road to birth control for men

Pills, injections, coil, rings, patches, caps, condoms, tubal ligation … there are more female contraceptive options than one can poke a stick with.

But for this multiplicity of female birth control methods, sexually active men only have vasectomy — considered a non-reversible technique — condoms, and the dubious pull-out method.

And for the more than 70 years, the earliest female contraceptive — the pill — has been around, there are still many unintended pregnancies.

According to the Population Council, over four in 10 pregnancies in Kenya are unintended; that is either mistimed or unwanted. Consequently, approximately 14 per cent of pregnancies in Kenya end in abortion.

These unsafe abortions result in about 2,600 deaths of women and girls every year.

Globally, according to a 2018 study published by The Lancet Global Health, 44 per cent of pregnancies around the globe are unintended, and about 40 per cent of these end in termination.

ONUS ON WOMEN

Because women are the ones who carry the pregnancies (and have more birth control choices), the onus tends to fall on them to arrange for prevention of unwanted pregnancies.

Yet many women cannot use hormonal contraception, for reasons such as the risk of dangerous blood clots. Moreover, not all women do what they are supposed to do to prevent conception.

Women have in some instances been accused of tricking men into conceiving with them. This probably explains why the search for a male version of the pill – the forerunner of the now sweeping possibilities – has been the white whale of reproductive health, with scientists eager to have men take equal charge for birth control.

The hunt for a male contraceptive pill has been on since the 1950s, when the female pill was invented.

Gregory Pincus, who co-invented the female pill, first tested the same hormonal approach on men in 1957, and various hormonal and non-hormonal methods have been explored since.

There have been thousands of attempts at a pill for men, but none has come to fruition — in spite of years of the occasional breathless news headline by upbeat researchers proclaiming ‘a solution in sight’.

“There is a prototype male pill and a long acting injection for men that are currently being tested by our colleagues in the USA sponsored by NIH and might ultimately be evaluated by the same investigators who are involved in this trial including our group in Kenya,” says Dr John Kinuthia, a obstetrician/gynaecologist at the Kenyatta National Hospital, who is leading a trial for one of the male contraceptives in Kenya.

“Other groups are evaluating non-hormonal methods for male contraception, but these are a little behind in terms of clinical development. There are some groups trying to develop a reversible vasectomy, particularly in India, and this may be another option at some point,” he adds.

Out of all the research, however, today a whole array run the gamut of several delivery methods currently under (well-known) active study around the world.

But just as many have long fallen off the research radar.

Several promising ones are quietly making their way through clinical trials, including a topical gel that blocks sperm production that is being tested right here in Kenya.

A male pill—the longest-researched method. Pills that will work in various ways have been sought.

Researchers in Scotland hope to make a breakthrough in the long hunt for a male pill, thanks to a grant of more than $900,000 from the Bill and Melinda Gates Foundation that will allow them to screen thousands of existing drugs to see if they have potential.

At the University of Berkeley another option — a pill out of herbs — is being pursued. According to lead researcher Dr Polina Lishko, who has been researching the sperm’s egg-seeking habits, this particular pill would work by suppressing the sperm’s power kick, to propel itself towards and into the ovum, thereby preventing it from reaching the egg.

Men would simply have to take the pill up to five hours before having sex for it to be effective.

It is being tested as an emergency contraceptive taken either before or after intercourse, or as a permanent contraceptive via a skin patch or vaginal ring.

Human sperms take about five to six hours to mature once they enter the female reproductive system, which is enough time for the drug to enter the system and block the kick.

Chemicals from the dandelion root, aloe vera, the “thunder god vine” plant and mango roots are being studied for the technique.

SPERM PRODUCTION

However, while compounds didn’t damage the sperm, they existed at such low levels in plants that the cost of extraction was very high.

The—Dimethandrolone Undecanoate (DMAU)— pill works similar to women’s birth control by combining a male hormone, testosterone, and a progestin.

Taken once a day, the pill was found to be safe in halting sperm production, and reducing testosterone production.

According to reports from its researchers at the Endocrine Society’s annual meeting in 2018. After about a month of treatment, the pill had reduced levels of hormones that are necessary for sperm production, with no troubling symptoms that can arise with a dramatic drop in testosterone.

Senior investigator Stephanie Page said that the pill which has to be taken with food, blocks receptors in the brain to shut off hormones required for sperm production.

A clean sheet pill — called the ‘clean sheet’ pill because no semen is produced during the sexual encounter.

The pill in the early stages of research works by preventing the release of sperm and the fluid they are carried in.

NATURALLY RECYCLED

This quick-acting pill closes the sperm-carrying tubes, preventing passage of both semen and sperm.

They remain in the tubes and are naturally recycled by the body.

It simultaneously prevents spread of sexually-transmitted infections including HIV. The pill is recommended for use two to three hours before a man has sex. The effects of the pill are temporary, and wear off within 16 to 24 hours.

Researchers are also exploring the idea of using the same compounds to make an implant to be used under the skin to continually release small amounts of the drug, which then provides men with round-the-clock protection.

The clean sheet pill has so far only been tested in animals. Would men accept the mechanism of action — a semen-free orgasm — even if it feels exactly the same?

HORMONE-FREE

Hormone-free oral pill. Scientists at the Monash Institute of Pharmaceutical Sciences in Australia are also developing a hormone-free oral pill that would work by stopping sperm from getting into the ejaculate. Animal tests showed the sperm could be “kept in storage” during sex.

Originally developed as a potential treatment for cancer, the compound blocks a protein that is involved in sperm production, and is reversible.

The jab—In a 2016 phase II study in Germany, a male contraceptive injection was found to be 96percent effective in preventing pregnancy – but with side effects like acne, increased libido and mood swings.

The men got two injections in the buttocks with a combination drug comprising the “female” hormone progestogen and the “male” hormone testosterone, every eight weeks.

Troublingly, around five per cent of men had not recovered their sperm count one year after stopping the injections. All the same, more than three-quarters of the men – and their partners – said they would be happy to continue to use this form of contraception, if potentially serious complications were addressed.

Scrotal injection — An injectable gel is among the interventions on trial for its ability to do a ‘temporary vasectomy’.

The gel is injected into the scrotum, the vas deferens—the small duct between the testicles and the urethra that takes the sperm from the testicles to the penis during ejaculation.

The gel allows seminal fluid to be released during ejaculation but blocks sperm, which are reabsorbed by the body.

When the man wishes to restore flow of sperm, the gel is dissolved using a second injection and flushed out.

The method which takes effect immediately it is injected, has shown to be highly effective at 99 per cent at preventing pregnancy.

This method has been on trial since 2010 and its main selling point is that it does not interfere with the man’s hormones.

Male implant—The implant under development by the Population Council relies on a synthetic steroid code named MENT. The one-year implant is placed under the skin of the upper arm.

Four implants suppress secretion of gonadotropin completely (a hormone that stimulates the growth and function of the testes), leading to significantly reduced sperm count.

Eight of 11 men with four implants had zero sperm count, which lasted several months until the implants were removed.

Research is ongoing to produce new prototype implants that would deliver a higher daily dose in order to reduce the number of implants needed to be effective.

If approved by regulatory authorities, it would be the first long-acting reversible male contraceptive.