RISUG is a one-time injection that’s long-lasting, reversible and has shown no serious side effects in clinical trials thus far. Dr. Sujoy K
An Indian scientist has spent the past 50 years waiting for the world to accept his revolutionary medical breakthrough — one with global implications for both humans and animals. Dr. Sujoy Kumar Guha's innovation is a male contraceptive known as RISUG: a one-time injection that's long-lasting, reversible and showed no significant side effects in a 2018 clinical trial. But Guha has faced hurdle after hurdle along the way. As he says in the documentary The Scientist Who Runs at Night, he believes roughly 15 of those years were spent facing "unjustified" delays. His invention challenges a pharmaceutical industry that makes billions of dollars on long-term methods of contraception, while his solution is a one-time fix. RISUG — an acronym for reversible inhibition of sperm under guidance — is a gel that affects the electrical charge of sperm. The head of sperm carries a negative surface charge. When RISUG is injected in the vas deferens, it produces a positive charge. And when the sperm head is exposed to that positive charge, the sperm membrane breaks down. "This sperm becomes incapable of fertilization. One injection, the RISUG forms a long-standing implant. That is why it is effective for many, many years," Guha says in the documentary. The idea struck Guha in the early 1970s while he was investigating inexpensive ways to purify rural water systems. He discovered that a common polymer could kill bacteria in water when pipes were coated with it. Guha then realized this could have applications for human health. He theorized this polymer could be deployed in the narrow tubes where sperm travels. The Indian government had been interested in family planning options in the heavily populated and rapidly growing nation, so Guha suggested developing a male contraceptive based on his idea. He also wanted to create another contraception option for males. Guha started testing in rats, rabbits and two species of monkeys. "When I first made this RISUG male contraceptive using electrical charge, everyone laughed! 'What's the connection between contraception and electrical charge?'" he says in Bengali in the documentary. "When it advanced [and was] successful on animals, then the opposition began." The first issue was that Guha was an electrical engineer, not a medical doctor. The Indian Council of Medical Research would not allow clinical trials on humans for a drug developed by someone without a medical degree. Guha's response? He got a medical degree. He would teach an engineering class at the Indian Institute of Technology at 7 a.m., and then become a medical student at University College of Medical Sciences at 8 a.m. But the hurdles kept coming: concerns about the polymer being toxic, changing legal requirements for manufacturing, initial alarm over urine tests (that Guha says was unfounded), extensive bureaucratic delays. Fundraising was also an issue — an inexpensive, one-time medical fix was not as attractive to companies that were more interested in long-term profits. Guha says that international pharmaceutical companies and health institutions preferred other hormone-based contraceptives with higher profits, and caused further delays to his work. "But I'm used to fighting," he says. After several decades spent overcoming obstacles, 2018 brought the verdict: a study showed that RISUG was 99 per cent successful in preventing pregnancy in human trials, with no significant side effects. Within a few years, the Delhi Legislative Assembly approved the use of RISUG contraceptive for stray dogs and monkeys to keep populations down (but the COVID pandemic delayed the project). In 2020, Guha was awarded the Padma Shri, one of the highest civilian honours in India. In 2024, RISUG landed a manufacturing facility at SGT University in Gurugram, India. Guha expects that it will be operational in 2025. It's been more than 50 years since Guha first started working on RISUG. ... For the 84-year-old scientist and doctor, the long journey has given his life purpose.
If you are interested, you can watch 'The Scientist Who Runs at Night' on the CBC Gem app for free.
