India’s reversible procedure could cost as little as $10 in poor countries, and may provide males with years-long fertility control, overcoming compliance problems and avoiding ongoing costs associated with condoms and the female birth-control pill, which is usually taken daily. For Sujoy Guha, the 76-year-old biomedical engineer who invented the product, the challenge is to now find a company who wants to sell it. Guha’s technique for impairing male fertility relies on a polymer gel that’s injected into the sperm-carrying tubes in the scrotum. The gel, which has the consistency of melted chocolate, carries a positive charge that acts as a buffer on negatively charged sperm, damaging their heads and tails, and rendering them infertile. The treatment, known as reversible inhibition of sperm under guidance, or RISUG, is reversed with a second shot that breaks down the gel, allowing sperm to reach the penis normally
