As many Canadians trade snow for surf over the Christmas break, few think about the painful surprises that can come with a beach vacation. Jellyfish, fire coral and the invasive lionfish can turn a sunny afternoon into a medical emergency, with pain strong enough to cut a trip short.
That problem is what led McGill University pain researcher Reza Sharif-Naeini to create StingMaster, a topical cream now used by divers and beachgoers around the world to treat potentially debilitating stings.
The breakthrough wasn’t part of his research agenda. It began on a plane.
“I was flipping through an in-flight magazine and there was an article about lionfish,” Sharif-Naeini said. “It has spines packed with venom and they cause excruciating pain.”
For divers and fishermen, he adds, “the sting doesn’t kill you, but you wish you were dead.”
The curiosity followed him off the flight.
“I got to Montreal in the lab and searched the literature and nobody had looked at the pain from this venom,” he said. “I thought, let’s try it.”
From curiosity to discovery
As Director of the Alan Edwards Centre for Research on Pain, Sharif-Naeini has a background in pain transmission that made the leap natural. He had previously worked in San Francisco with a researcher focused on toxins and venoms, including the Texas coral snake. Within weeks of returning to Montreal, he sourced lionfish from local pet shops, purified the venom and began testing it on neurons.
The results were immediate. The venom activated a distinct class of pain fibres and produced explosive, long-lasting pain signals. Divers told Sharif-Naeini the only known treatment was scalding hot water.
“They’d put the stung area in water as hot as they could manage, pull it out, then put it back in for an hour,” he said. “They got maybe 20–per–cent decrease in pain.”
After Sharif-Naeini’s team identified a synthetic molecule that blocked the venom’s effect, they hit a wall. The molecule belonged to a major pharmaceutical company that refused permission to use it.
“I was not happy,” he said. “We have all these people getting stung. We found a way to block it, but we weren’t allowed to pursue it.”
Bootstrapping a solution
Sharif-Naeini kept looking and eventually found a similar blocker occurring naturally in a plant extract. That discovery meant he could create a topical cream without the lengthy, expensive clinical trial process required for synthetic drugs.
Investors encouraged the effort but declined to commit funds.
“They said the market was too small, because there are only 10,000-20,000 lionfish stings a year,” Sharif-Naeini said.
So, he bootstrapped the project.
“We borrowed money, line of credit, everything, to file the patent and register the company,” he said. Within a year they had a manufacturer and distributor.
But before selling it, they wanted first–hand proof.
Sharif-Naeini and his student injected themselves with purified venom.
“The pain shoots up to an eight or nine out of 10 within two seconds,” he said with a chuckle. “As long as you don’t treat it, it stays there.”
After five minutes, they applied the cream.
“Within three or four minutes, the pain dropped to a four.”
They repeated the tests, including stings from live lionfish. The results held.
“We were able to show we were back to doing our regular thing within an hour,” Sharif-Naeini said. For divers, that meant a ruined day could become a brief delay.
Beyond lionfish
Once the cream reached users, something unexpected happened. Divers began reporting broader effects.
“People started to get back to us and say, your cream works even faster on jellyfish stings,” Sharif-Naeini said. Others said it relieved sea urchin and fire coral stings. Others reported StingMaster relieved wasp and bee stings and even offered relief from the itch of mosquitos and black fly bites.
Mechanistically, it made sense. Many venoms activate the same pain pathway, and the cream blocks that pathway. What began as a niche tool for lionfish encounters became a versatile sting treatment for travellers and families.
A McGill success story
Sharif-Naeini says the experience shows how McGill-based research can ripple out into the world.
“It’s interesting for McGill to know that a discovery made in the labs is actually having an impact on people who get stung,” he said.
