Health Canada has issued an alert over capsules marketed to men for "long lasting vital energy" after a test of one version of the supplement detected a prescription medication used to treat erectile dysfunction.

Health Canada said Vita-X Revitalizing Capsules may pose a serious health risk and is now illegal to sell in Canada after a product licence associated with the supplement was suspended.

There are two version of the capsules. The first had seven capsules and a Natural Product Number of NPH 80053009 on the label. The second version, the one tested and found to contain the erectile-dysfunction drug sildenafil, comes as a single capsule and does not have an NPH on the label. Lanlay Healthmetic Inc. confirmed both are made by the same manufacturer, Health Canada said, meaning it’s possible both could contain sildenafil.

Consumers are advised to stop using the supplements and report any adverse effects.

Health Canada said sildenafil should only be used under professional supervision and taking it in conjunction with other drugs could lead to life-threatening effects. People with heart problems are also at increased risk of side effects from taking the drug.