Why is a male birth control Illustration of a fetal pill not around yet?

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BY ANDREJA GREGORIC

MEN are still limited to only a few forms of birth control. Scientists are making constant progress but the birth control pill or any other hormonal contraceptives for men are still years away from being safe, reversible, and broadly available. In the past, low demand and focus on women contraceptives partly limited development. Now, more and more men want to take control over their own fertility.

Nowadays, despite the rise in demand for male hormonal contraceptives they are still basically nonexistent.

“The only options currently available for men are vasectomy, condoms and coitus interruptus,” Stephanie Page, an endocrinologist at the University of Washington School of Medicine, said for CNN. “Forty per cent of pregnancies worldwide are unplanned, so there’s clearly an unmet need for novel contraceptives, and men have very few options.”

A vasectomy is considered irreversible and involves a minor surgical procedure that prevents the transmission of sperm by cutting the vas deferens, a duct that transports sperm from the testes to the urethra. The condom, on the other hand, is far less invasive but has a high user failure rate and coitus interruptus (withdrawal or pullout method) is significantly less effective than most other methods of contraception.

One of the obstacles in the development of male hormonal contraception is that women produce one egg per month and men produce 1,000 sperm per second. Although clinical trials began almost fifty years ago, current methods still present unpleasant side effects. They are based on the use of exogenous testosterone, alone or in combination with a progestin, to suppress the production of testosterone in the body and consequently halt spermatogenesis.

Current development includes long-acting injectables, transdermal gels and novel androgens that may have both androgenic and progestational activities. Common side effects include acne, injection site pain, mood swings, including depression, aggression, and changes in libido.

Such unpleasant side effects even caused participants to drop out of a clinical trial involving a male birth control shot, cutting the study short. Available oral forms of testosterone may cause liver inflammation and clear the body too quickly for convenient one-per-day dosing.

Recently, one research team developed a new birth control pill for men that appears to be safe when used daily for a month. The study was presented at ENDO 2018, the annual Endocrine Society meeting. The active ingredient called dimethandrolone undecanoate or DMAU, reduced testosterone and other hormone levels responsible for sperm production without any serious side effects. Because of androgen-like properties it “tricks” the body into thinking that testosterone levels are adequate and the long-chain fatty acid undecanoate ensures the drug stays in the user’s system for a full day.

“DMAU is a major step forward in the development of a once-daily ‘male pill’,” said Paige for Endocrine Society, lead author of the study. “Many men say they would prefer a daily pill as a reversible contraceptive, rather than long acting injections or topical gels, which are also in development.”

The study included 100 healthy men, of which 83 completed the study. The investigators tested three different doses of DMAU (100, 200, and 400 milligrams) and two different formulations inside the capsules (castor oil and powder). Subjects took the drug or placebo for 28 days once daily with food. Testosterone in their blood dropped to castrate levels for all three doses. They gave blood samples, for hormone and cholesterol testing, on the first and last days of the study.

The men who took the highest dose, 400 mg, showed a “marked suppression” of testosterone levels, as well as the levels of two hormones needed to produce sperm. “Normal testosterone in a man is anywhere from 350 to 1,100 nanograms per deciliter,” said Seth Cohen, an assistant professor of urology at NYU Langone Health, who was not involved in the study. “And they got these guys down to 13 nanograms per deciliter.”

All groups taking DMAU did have mild weight gain and decreases in HDL, the good cholesterol. All subjects had normal markers of liver and kidney function. One of the study’s main limitations is that it did not measure sperm count.

“These promising results are unprecedented in the development of a prototype male pill,” Page said. “Longer term studies are currently underway to confirm that DMAU taken every day blocks sperm production.”

Younger generations look to share the responsibilities of contraception and family planning, so choices for contraception should be available to men, too. According to Page, we can expect male contraception pills in less than a decade.

“There are a number of targets that are being actively pursued: sperm motility, sperm-egg fusion, and various aspects of sperm development,” Page said for Endocrine Newsin 2016. “Thus, the 10-year benchmark that we have talked about for a few years now looks more promising than in the past.”

The partnership between the government, academia, industry and the public may generate adequate interest and collaboration to develop and market the first male hormonal contraception soon. – First published in Splice on July 4.