Topical gel is latest in decades-long quest for hormonal male birth control

In the world of family planning, birth control methods have remained largely the same for men for decades, relying primarily on condoms and vasectomies. Hormonal birth control, shots and pills, on the other hand, have long since been considered treatments for women and women alone to consider.

This could soon change, however, according to a study published last month.

Researchers shared the most recent findings in the development of a hormonal option for male birth control, a gel that is applied topically, following a successful clinical trial with more than 300 participants.

Researchers called the existence of such a method an "unmet need,” a sentiment that seems to be shared among American men. In fact, a 2017 survey of 1,500 men living in the U.S. found that 85% of participants wanted to prevent their partner from getting pregnant and taking responsibility for birth control was the key reason for wanting a new male contraceptive method.

Still, we are a ways away from a commercial product. Why has it taken so long? Or rather, how did we get from sheep intestines to pills and hormonal gels? Here's a brief overview of male birth control through the centuries.

Male birth control: What's getting in the way, sexism or science?

The latest invention, a hormonal gel, could be coming soon

Last month, researchers with the National Institutes of Health (NIH) published a study detailing the workings of a novel male contraceptive gel that has been under testing since 2005.

Made with a combination of hormones called segesterone acetate (called nestorone) and testosterone, the gel is rubbed on the shoulder once daily and works by suppressing sperm production.

The nestorone in the gel inhibits the production of testosterone in the testes themselves, lowering sperm count to the desired level of 1 million or fewer sperm per milliliter of semen.

This suppression happened more quickly than in past studies, with 86% of the 222 men participating reaching the desired count by week 15. Of those men, a midpoint of sperm suppression was reached in less than 8 weeks, compared to prior studies which took between 9 and 15 weeks.

Testosterone does more for the body than simply control sperm production, however, meaning the suppression of the hormone for birth control has some limitations.

“The development of a safe, highly effective and reliably reversible contraceptive method for men is an unmet need,” said senior researcher Diana Blithe, Ph.D., chief of the Contraceptive Development Program at the National Institutes of Health (NIH), in a press statement. “While studies have shown that some hormonal agents may be effective for male contraception, the slow onset of spermatogenic suppression is a limitation.”

Studies are ongoing to test the contraceptive’s effectiveness, safety, acceptability and reversibility of contraception after treatment stops.

Past attempts at new birth control methods for men

The new gel is not the first foray doctors and scientists have made into developing a hormonal form of male birth control.

In 2016, a study published in The Journal of Clinical Endocrinology & Metabolism found that a form of male birth control studied between 2008 and 2023 was nearly 96% effective. The method entailed a series of injections that lowered sperm count and resulted in only four pregnancies out of the 266 men who participated.

However, the study was eventually ended early after men taking it reported unfavorable side effects that made them no longer want to participate, including mood swings, an altered libido and acne. Reports at the time noted that these symptoms are typical of the hormonal birth control women take every day and have for decades.

In 2019, a male birth control pill passed early safety tests performed by the nonprofit LABioMed and the University of Washington in Seattle. The drug, called 11-beta-MNTDC, "greatly" reduced hormones needed for sperm production in an early study, though researchers told USA TODAY it would likely take 10 years for it to become available in its final, marketable form.

In February 2023, researchers at Weill Cornell Medicine tested a non-hormonal drug that could be taken orally or via injection that made male mice temporarily infertile. The study found that the mice’s fertility returned with minimal side effects hours after stopping the medication, meaning this pill could be taken by men only "as needed."

In Indonesia, a similarly-acting, plant-derived form of male birth control was studied in the 2010s and found to be 99% effective. The plant, called gendarussa, contains enzymes that perform a similar temporary inhibiting function as the drugs mentioned above.

Traditional forms of male birth control

Withdrawal and fertility tracking

Perhaps the oldest form of birth control out there, the "pull-out" or "withdrawal" method entails withdrawal before ejaculation occurs, presumably preventing sperm from entering a woman and fertilizing an egg.

Such an act is even mentioned in the bible, where in Genesis 38:9, it is said Onan “spilled his semen on the ground to keep from providing offspring.”

This method has often been used in conjunction with fertility tracking. Couples may abstain from intercourse when a woman is ovulating or at a point in her cycle of high fertility to enhance the effectiveness of birth control through withdrawal.

However, the method, which some studies suggest may remain one of the most popular, does not offer any protection against STIs and has a high failure rate of about 22 out of 100 people becoming unintentionally pregnant or about 1 in 5, according to the U.S. Office of Women's Health.

Condoms

Male condoms, which work as a physical barrier to keep bodily fluids contained, are about 98% effective at protecting against STIs and pregnancy.

Condoms, made of animal intestines, usually sheep, calves, or goats, have been around since at least medieval times, according to research published by medical historian Vern Bullough, but may have existed even earlier.

It wasn't until the 16th century that condoms were widely suggested by doctors for protection against venereal disease, and the rubber condom wasn't produced until 1855, according to Case Western Reserve University.

The rubber vulcanization process, patented by Charles Goodyear in 1844, entailed wrapping raw rubber around an appropriately shaped mold and applying a chemical solution to then cure the rubber. In 1920, the more modern latex condom was invented and grew in popularity thanks to both being more effective and easier to produce.

Vasectomy

The most permanent form of birth control men currently have available to them is vasectomy.

The outpatient procedure, which is typically performed in about half an hour, entails the cutting and sealing of tubes called the vas deferens, blocking the passage of sperm from the testicles to the urethra and stopping the sperm from being released during ejaculation.

This serves as a permanent form of birth control with an almost 100% success rate. The procedure is considered safe and effective and is performed on about 500,000 men per year in the U.S., according to the Cleveland Clinic.

The first vasectomy on record was performed on a dog in 1823 by Sir Astley Cooper as an alternative to complete castration. In humans, it was initially used as a means of symptom relief for an enlarged prostate, and the literature reflected over 100 vasectomies done for this purpose by 1900, according to the William P. Didusch Center for Urologic History.

In the U.S., vasectomies as a form of family planning were first promoted in the 1950s and by the mid-1960s, roughly 40,000 were performed each year.

This article originally appeared on USA TODAY: Male birth control options range from a new gel to classic condoms