New contraceptive gel for men shows promise in early studies

Until now, contraception for men was limited to condoms or a vasectomy. But now researchers have developed a gel that, when applied to a man’s bare shoulders, can help reduce sperm production.

This simple gel is a hormone-based treatment that has shown promising results in clinical trials.

A hormone gel is usually applied to the shoulders, because this part of the skin is suitable for transdermal drug administration. The skin on the shoulders has a good balance between thickness and blood flow, allowing it to effectively absorb hormones into the bloodstream. There is minimal contact with others and the application is simple because it concerns a large surface.

Researchers from the National Institutes of Health (NIH) presented promising phase 2 trial results for the new hormonal gel at the Endocrine Society conference in Boston.

The trial, part of the NIH Contraceptive Development Program, involved 222 men aged 18 to 50. The participants applied 5 milliliters of the gel (about a teaspoon) to their shoulder blades daily.

Preliminary findings indicate that the gel works faster than expected.

A hormone gel is usually applied to the shoulders, because this part of the skin is suitable for transdermal drug administration. (Photo: Getty Images)

After 12 weeks, 86% of participants achieved sperm suppression, defined as having up to 1 million sperm per milliliter of semen, which is considered effective for contraception.

The average time to reach this level was eight weeks, a significant improvement over previous methods that took longer.

Normally, the normal sperm count ranges from 15 million to 200 million per milliliter without contraception. The rapid effectiveness of the gel is encouraging, especially since previous attempts required higher doses of testosterone, which can cause side effects.

The new gel combines testosterone and Nestorone, a synthetic hormone called segesterone acetate, allowing it to work faster and with lower doses of testosterone.

Nestoron is already used in contraceptives for women, such as the vaginal ring. In men, the combination of Nestorone and testosterone suppresses sperm production without affecting sex drive or causing other side effects.

So far, participants have maintained normal sexual function with low testosterone levels in the blood.

Researchers are now monitoring the gel’s effectiveness in preventing pregnancy. Male participants, who must be in a committed, monogamous relationship, need their partners’ permission to use the gel as their only method of contraception.

Couples should have sex at least once a month for a year, with men undergoing periodic sperm count tests to measure fertility.

The gel still needs to be approved by the US Food and Drug Administration (FDA).

“Although studies have shown that some hormonal agents may be effective for male contraception, the slow onset of spermatogenic suppression is a limitation,” said senior investigator Diana Blithe, head of the Contraceptive Development Program at the NIH.

The sperm suppression phase of the international Phase 2b trial of segesterone-testosterone gel has been completed.

The study continues to test the effectiveness, safety, acceptability and reversibility of contraception after treatment has stopped.

Published by:

Daphne Clarance

Published on:

June 5, 2024