This 84-year-old scientist has spent almost 50 years developing a male contraceptive

CBC

28-01-2025

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.
'Everyone laughed … then the opposition began'
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.
How male contraceptive drug RISUG works — and how it's different from a vasectomy
Duration 1:04
Dr. Sujoy Kumar Guha has spent almost 50 years developing a male contraceptive called RISUG. The one-time injection is long-lasting, reversible and has shown no significant side effects in clinical trials thus far. In this clip from documentary The Scientist Who Runs at Night, Guha explains how RISUG works. Watch it now on CBC Gem or The Nature of Things YouTube channel.
"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.
Guha was an electrical engineer when he first developed RIGUG, but the Indian Council of Medical Research would not allow clinical trials on humans for a drug developed by someone without a medical degree. So he went to medical school. (Nightalley Productions)
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.
'I have never seen him break down because of setbacks'
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.
Guha, left, looks on as a patient receives a RISUG injection. (Nightalley Productions)
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.
"His uniqueness is that he sticks to his decision," says his wife, Rita Guha, in Bengali in the documentary. "He doesn't care about whether it's a yes or no. Even if it's negative initially, he keeps at it. I have never seen him break down because of setbacks."
For the 84-year-old scientist and doctor, the long journey has given his life purpose.
"Of 10 things that you do, if one or two becomes successful, that's great," Guha tells students in the documentary. "Struggle! And don't look for rewards. If it comes, it comes."
Watch The Scientist Who Runs at Night on CBC Gem and The Nature of Things YouTube channel.