Forget condoms? Researchers begin work on magnetic contraceptive for men

The science

There is still a long way to go, but researchers have developed a potential male contraceptive method based on magnetic, biodegradable nanoparticles.

The magnetic-thermal approach by Weihua Ding, Fei Sun, and colleagues is said to be safer and more effective than previous measures using heated nanoparticles. In addition, it is not necessary to inject nanomaterials into the testes, and the procedure prevents heat burns to the skin. 

The researchers injected repeated doses of nanoparticles into the bloodstream of mice, guided the nanomaterials to the testes with magnets, and then applied an alternating magnetic field for 15 minutes.

The nanoparticles heated the testes, and the mice were unable to father boys seven days after treatment. However, by the end of the 60th day, they were again able to produce about 12 young per pregnant female. The nanoparticles were not toxic and gradually excreted from the body.

Why it matters

For as long as contraceptives have existed, women have been responsible for using them. From hormone-altering pills to painful implanted IUDs, many women have to deal with side effects that are often dismissed or neglected. Contraceptive options for men, on the other hand, are severely limited. The options are either unsafe and temporary, like condoms, or extremely difficult to reverse, like vasectomy.

Promising male contraceptive pills so far have failed due to their side effects in clinical trials. A functional and safe contraceptive for men could therefore change the way we use contraception and promote greater equality between men and women. 

Even though this technology is still in its infancy, noninvasive and controllable magnetic nanoparticles could soon play an important role in biomedicine or biotechnology. They appear to be well-tolerated by human cells, and can thus be used effectively and efficiently in biomedical applications—for example, in imaging diagnostic procedures or in the targeted transport of active substances into the organism.

This development may well lead to a new enabling technology, similar to mRNA technology, that will change the way medical treatment is delivered in the future.