OTTAWA -- Health Canada says all lots of an authorized natural health product promoted for sexual enhancement are being recalled.

The agency says one lot of the ca was found to contain an undeclared prescription drug called tadalafil which should only be used under the supervision of a health-care practitioner.

Forta for Men, which is also sold as "Doctor's First for Men" and "Dr. First for Men," is manufactured by Natural Performance Products Ltd., and the distributor, Vivo Brand Management Inc. of Cornwall, Ont., is recalling all lots as a precautionary measure.

Health Canada says tadalafil should never be used by people taking any kind of nitrate drug such as nitroglycerine as it can cause potentially life-threatening low blood pressure.

People with heart problems, including high blood pressure, are at higher risk of cardiovascular side effects if they use tadalafil and engage in sexual activity.

The product, which is sold in packs of two, 10 or 15 capsules, is available in retail stores across the country and online.