The Poison That Heals

A tiny dose could kill you, but a teeny tiny dose may kill your pain instead—leaving you unharmed.

Blowfish poison, which has been used in many cultures to treat heroin addiction, migraines, and other types of pain, has never achieved widespread acceptance because of its lethal potential. But a Canadian pharmaceutical company has just figured out how to make very small, safe doses. In recent clinical trials, the poison has been remarkably effective at treating cancer patients with extreme pain, including nerve pain, something opiates don’t really relieve—without being addictive or sedating.

Tetrodotoxin, the poison’s active ingredient, is a good painkiller for the general population, too, says Howard Cohen, a pain specialist who is medical adviser to International Wex Technologies, the Canadian company that plans to market the substance in drug form. And though its full range of side effects won’t be known until it becomes more widely used, the research so far is promising, says James Dillard, a physician and author of The Chronic Pain Solution. “Treating pain is so difficult,” he says. “We’re glad for anything we can add to our arsenal.”

Blowfish poison has just been approved for the final phase of clinical trials by Health Canada, the Canadian equivalent to the FDA. If all goes well, a painkiller derived from it could be available in Canada and the United States within two years.