4 new male contraceptives are being studied to reduce unplanned pregnancy across the world, and to give men not only the option that women bear but also the burden of birth control.
There are various reasons why male contraceptive research is lacking in comparison to female contraceptives.
“The male produces hundreds of millions of sperms every day, and when the ejaculate comes out, there are 250 million sperm,” said Michael Skinner, a reproductive biologist who studies male contraceptives at Washington State University. “We could probably get away with a tenth of that and still be fertile.” Women, in comparison, only produce one or two eggs a month.
The other main issue is side effects. In 2016 a large clinical trial of injectable hormonal contraceptives for men was stopped because of concerns about side effects. Many were quick to criticize the men of not being able to handle the same side effects and discomforts what women face every day on the contraceptive pill. However, 75% of the participants wanted to continue the trial. 1 of the 2 independent committees monitoring the safety data of the trial was so concerned about the side effects that they shut down the trial.
The majority of the male contraceptives being studied are hormonal contraceptives aimed at lowering sperm production.
Researchers modeling the impact of male contraceptives suggest that even if only 10% of men used an effective form of male contraception, we’d see unintentional pregnancies fall by up to 5% in the United States and South Africa, and as much as 38% in Nigeria.
1. The male contraceptive gel
The male contraceptive gel is the furthest along in clinical trials.
The gel is called Nestorone-Testosterone. The gel contains testosterone and progestin, a synthetic form of the female hormone progesterone. Men naturally have progesterone too, but only at low levels compared to women.
The gel is meant to be applied to the arms and shoulders every day. It works to shut down the gonadotropin hormones which are responsible for stimulating testosterone production in the testes.
However, when you lower the testosterone in the testes, you also lower testosterone in the blood. This can give side effects such as a low libido or problems with ejaculation. This is why the gel contains some replacement testosterone to keep everything else functioning well.
A 24-week study published in 2012 showed that the gel suppressed sperm levels in almost 90% of men to 1 million per milliliter or less, around the amount needed to prevent pregnancy, and with few side effects.
A major, international trial involving 420 couples in the US, UK, Sweden, Chile, Kenya, and Italy will start this summer. The couples will only use the gel as a contraceptive for 12 months to test its effectiveness at preventing pregnancies.
If the trial shows the gel to be effective and safe, the gel will move into a phase 3 study involving even more couples.
Due to the length of the trials and medical requirements, we may still be waiting 10 years before something like this may be available.
2. The male daily birth control pill
Previously male birth control pills were found to clear the body so quickly that they required more than one dose a day, but now there are hopes for a once-daily pill.
Recently, researchers presented data from a 100-person randomized controlled trial showing that a male birth control pill appeared to be safe when used every day for a month.
The birth control pill contains dimethandrolone undecanoate, or DMAU, a synthetic anabolic steroid, also being studied for birth control.
The effects of DMAU stayed in the blood for at least 18 hours, suggesting that it would only need to be taken once a day.
The pill works in a similar way to the birth control gel. DMAU has properties of both testosterone and progestin and the resulting hormonal changes suggested that the pill suppressed sperm production.
However, the researchers say they don’t know that for sure as they didn’t measure sperm suppression due to the study being too short.
3. The long-term injectable contraceptive
Much like the male contraceptive pill, DMAU can also be used as an injectable contraceptive.
Researchers at Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center and the University of Washington are currently recruiting volunteers for a phase 1 clinical trial to test an injectable form of DMAU.
Research in animals has shown that injectable DMAU could suppress sperm production for several months at a time, and that sperm levels return to normal after the injection wears off.
Researchers believe the DMAU injection will have a slower release, and so could be like a Depo-Provera for men, as opposed to needing to take a pill.
The most common side effects include acne, injection site pain, mood disorders, and an increased libido.
We’ll know more about its effectiveness and safety after the first study.
4. The non-surgical vasectomy
A traditional vasectomy involves cutting or tying the vas deferens to stop sperm from entering the urethra and being passed onto a partner.
Researchers in India are fairly far in their development of a non-surgical vasectomy called RISUG, which stands for Reversible Inhibition of Sperm Under Guidance.
Discovered by biomedical engineer Sujoy Guha of the Indian Institute of Technology, the idea involves injecting a polymer gel into the vas deferens to block sperm rather than cutting or tying.
The treatment can reportedly be reversed easily with a shot that breaks down the gel.
A submission being made to regulators this year will seek approval for RISUG as a permanent method of birth control.
The procedure is 98% effective at preventing pregnancy, about the same as condoms according to R. S. Sharma, Head of Reproductive Biology and Maternal Health at the Indian Council of Medical Research.
540 men in India have received the treatment, where it continues to prevent pregnancy in their partners 13 years after their treatment, he said.
Sharma also noted that India has mo0re married women with an unmet need for family planning than any other country, and that social stigma and a lack of privacy in stores has kept condom use to less than 6%.
In the United States, the Parsemus Foundation has licensed the RISUG technology.
Parsemus have developed a related product called Vasalgel, which is currently only in the preclinical phase of testing.
The results from rabbit and monkey studies are promising, according to Parsemus. However, no human trials are scheduled yet despite the hype about Vasalgel.
Will people use them?
A lot of the lack of development of male contraceptives to date has been said to be attributed to a lack of male interest.
However, an increasing amount of men are willing to try the methods, especially if proven safe and effective.
In a survey conducted with 134 young adults aged 18-27, 61 of which were male, their average likelihood for supporting male contraceptives was 8.6 on a scale of 1 to 10.
Would you use them, and if so, which would you choose?
Would you promote male contraceptive use to your children?