Health Canada has advised people who have previously had a heart attack not to use L-arginine supplements. The announcement comes in the wake of a recent study, published by the Journal of the American Medical Association, which showed an increased potential risk of death when the supplements were used after a heart attack.

L-arginine is an amino acid that is commonly used to sustain and promote healthy heart function.

All L-arginine products must carry a warning on their label that reflects the recent scientific information, stated Health Canada. The organization issued a stop-sale and recall on L-arginine-containing products that do not have the appropriate labeling. Products containing L-arginine must now have also market authorization before they can be sold in the country.

The group added, however, that in patients with heart disease who have not had a previous heart attack, taking L-arginine is unlikely to present a risk and may provide benefits, since the supplement may help the body repair damage to blood vessels in the heart.