Health Canada is warning consumers not to use bodybuilder dietary supplements called 6-OXO and 1-AD because they can trigger seizures and blood clots in the brain that can lead to lasting disability.
The department is also warning people not to use other supplements containing the ingredients found in 6-OXO and 1-AD, chemicals known as 4-androstene-3,6,17-trione and 1-androstenediol.
Both 6-OXO and 1-AD are manufactured by ErgoPharm-Proviant Technologies in Champaign, Ill., and are promoted for bodybuilding.
Health Canada says it has received one report of a serious adverse event linked to use of the supplements in this country.
A man who had no known medical conditions developed seizures and blood clots in his brain after using the supplements, which he had bought in the United States.
The product 6-OXO is an unauthorized natural health product in Canada, while 1-AD contains an anabolic steroid that is regulated as a controlled substance in Canada.
That means it can only be dispensed by prescription and used under the supervision of a health professional.
Neither is authorized for sale in Canada, but Canadians can buy them over the internet or while travelling abroad.
Anyone using either supplement, or others containing the same ingredients, should stop taking the products immediately and consult with a health-care professional if they have concerns, Health Canada says, adding it is taking action to block further importation of the products.