Canadian Government Warns Against the Use of Dietary Supplement L-Arginine in Patients Who Have Had a Heart Attack

On May 16, Health Canada, the Canadian equivalent of the U.S. Food and Drug Administration (FDA), warned the public not to use products containing the dietary supplement l-arginine if they have previously suffered a heart attack.

The basis for the warning was a study published in the January 4 Journal of the American Medical Association (JAMA), which found an increased risk of death in patients using l-arginine after a heart attack. L-arginine is widely promoted on the Internet for a number of conditions, including protecting the heart.

Health Canada also announced that all l-arginine products must carry a warning on their labels that reflects the results of the JAMA study. A ban and recall of all
l-arginine-containing products that do not have the appropriate warnings on their labels was also issued.  

The April 2006 issue of Worst Pills, Best Pills News carried an article about the JAMA research, which was a “gold standard” randomized controlled clinical trial funded by the National Institutes of Health. The independent group that was responsible for monitoring safety during the trial, called the Data Safety Monitoring Committee, stopped the study early after the death of six patients (8.6 percent) taking l-arginine versus no deaths in the patients taking a placebo.

As of press time, the FDA has done nothing to inform Americans about the risks of l-arginine as was done in Canada, once again highlighting the inadequacy of dietary supplement regulation in the United States. This is due to the Dietary Supplement Health and Education Act (DSHEA), a 1994 law which essentially immunizes the dietary supplement industry from FDA oversight and makes it quite difficult for the agency to take action against dangerous dietary supplements such as l-arginine.

DSHEA violates a basic American right to a marketplace free of untested products of questionable quality and safety whose producers can make unsubstantiated claims about safety and benefits.

What Should You Do  
You should not use l-arginine, especially after you have suffered a heart attack.

You should not use any dietary supplement. There is no credible evidence that these products are what they claim to be or can do what their producers say they can do.