Researchers have discovered a new birth control pill for males that is 99 percent effective in preventing pregnancy in tests in mice, a breakthrough that could balance the responsibility of using contraceptives between partners.
Presenting their findings at the American Chemical Society on Wednesday, scientists announced the creation of a new non-hormonal male contraceptive pill that effectively prevents pregnancy in mice without obvious side effects, according to Sky News.
After successful tests in mice, they hope to begin human trials in the second half of the year.
While women can take several pills or use patches or intrauterine devices, men only have access to single-use condoms which are prone to failure and largely irreversible vasectomies.
Vasectomies are surgical procedures that can potentially be reversed but are generally considered a permanent form of male sterilisation.
The reversal surgery could be expensive and not always successful, the researchers said, underlining the need for an effective, long-lasting but reversible contraceptive, similar to the birth control pill for women.
“Scientists have been trying for decades to develop an effective male oral contraceptive, but there are still no approved pills on the market,”Abdullah Al Noman, who is presenting the research work at the meeting, said.
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There are several compounds undergoing clinical trials but they target the male sex hormone testosterone, which could cause weight gain, depression and other side-effects.
“We wanted to develop a non-hormonal male contraceptive to avoid these side effects,” Noman, a graduate student in the Gunda Georg laboratory at the University of Minnesota, said.
Georg, who heads the medicinal chemistry department at the university, said: “Because it can be difficult to predict if a compound that looks good in animal studies will also pan out in human trials, we are currently exploring other compounds as well.”
In 2016, a study published in the Journal of Clinical Endocrinology and Metabolism, tested the safety and effectiveness of a contraceptive shot in 320 healthy men in monogamous relationships with female partners.
The researchers found that the shot effectively held the sperm count at 1 million per milliliter or less within 24 weeks for 274 of the participants, implying the contraceptive method was effective in nearly 96 percent of continuing users.
Four pregnancies (resulting in three live births) occurred among the men’s partners, all during the phase where other contraception was required.
All the babies were normal but there were serious negative effects resulting from the shots including one case of depression and one experience of an abnormally fast and irregular heartbeat after the injections stopped. The researchers considered one intentional overdose of acetaminophen possibly related.
Overall, 20 men dropped out early due to side effects. A total of 1,491 adverse events were reported by participants, including injection site pain, muscle pain, increased libido and acne. The researchers say that nearly 39 percent of these symptoms — including one death by suicide — were unrelated to the shots.
However, due to side effects, particularly depression and other mood disorders, the researchers decided in March 2011 to stop the study earlier than planned, with the final participants completing in 2012.
