One of the most long-lasting, promising male birth control methods in development is a gel injection.

Jamie Grill/Getty Images

RISUG, Male Birth Control’s Rising Star

Not that long ago, people in the medical community and the general public expected male birth control to mimic the landmark female birth control and hit the market in pill form. In actuality, the farther male birth control advances, the less likely it appears that a pill will fit the bill. Here’s just a sampling of the many male birth control options that have been floated in the past decade:

  • Radio controlled implant to block sperm flow with a click of a button.
  • Plugs that form sperm blockades in the vas deferens.
  • Testicular ultrasounds to zap sperm production for six months.
  • Heat treatments to induce temporary sterilization.
  • Rods filled with the hormone etonogestrel implanted into the arm.

One of the most promising male birth control options under investigation doesn’t involve popping pills, fiddling with remote controls or toting around bulging implants in one’s forearm. Attracting widespread media coverage since 2010, Reversible Inhibition of Sperm Under Guidance (RISUG) is a one-time gel injection that acts almost instantly to incite infertility in men. Developed 30 years ago by Indian scientist Sujoy Guha, RISUG, also known as VasalGel, sterilizes men for 10 to 15 years and also is completely reversible with a follow-up injection that dissolves the gel, according to human trials to date [source: Gifford].

The “gel” in VasalGel consists of a nontoxic polymer -- powdered styrene maleic anhydride combined with dimethyl sulfoxide, to be scientifically specific -- that coats the interior of the vas deferens and immobilizes sperm on their mass exodus out of the penis [source: Male Contraception Information Project]. The gel barrier not only makes it more difficult for sperm to squeeze through the confined tubing, but its chemical charge also fatally damages sperm membranes. So far, Indian men who have undergone a RISUG treatment have encountered no unintended pregnancies and experienced no secondary physical or sexual side effects [source: Gifford].

Why aren’t sexually active men everywhere lining up for a RISUG shot? As of this writing, the treatment is still in the clinical testing phases, but the scant attention it has received from pharmaceutical companies portends an uncertain future for male birth control.