Hardly a month goes by without scientists announcing that a new version of the male pill is “just over the horizon.” This month, the source of hope is a gene involved in sperm development, opening up the possibility of male birth control that doesn’t throw a guy’s hormones out of whack.

Currently, condoms and a vasectomy are the main options for men when it comes to contraception. A non-hormonal—and reversible—form of birth control would provide men with another, much-needed option.

The newly discovered gene plays a role in the development of sperm in the testes. Researchers from the University of Edinburgh identified the gene while working with genetically engineered mice. Without the gene, mice were infertile.

The gene, however, is only involved in the later stages of sperm development. A drug that blocks the activity of the protein created from the gene wouldn’t affect the early development of sperm. Unlike a vasectomy, which is largely permanent, the effects of this type of drug would be reversible.

This new discovery, published in PLoS Genetics, is promising, but finding a drug that can interact with the gene’s protein inside the cell will be “relatively difficult,” Dr. Lee Smith, one of the researchers told the BBC.

It may be some time before this sperm-suppressing drug hits the shelves. While you wait, if you want a non-hormonal form of contraception, stick to using condoms. They are effective, and also protect against sexually transmitted diseases.