Health Canada has seized counterfeit Cialis from South China Herbs Market Inc. in Toronto, Ontario (493 Dundas St W), in addition to several other unauthorized sexual enhancement products and an unauthorized skin treatment product . The manufacturer of Cialis has confirmed that the seized product is counterfeit and that the lot number and expiry date on the blister packs are not valid. Selling counterfeit health products in Canada is illegal. Counterfeit drugs are made to look like authentic products, but they are not the same and may pose serious health risks. They have not been assessed by Health Canada for safety, efficacy and quality and may contain: no drug at all a higher dosage than shown on the label dangerous contaminants and hidden ingredients Like the authentic version, the seized product is labelled to contain the prescription drug tadalafil. Tadalafil should be used only under the supervision of a health care professional. It should not be used by people taking any kind of nitrate drug (e.g., nitroglycerin) as it can cause potentially life-threatening low blood pressure. People with heart problems are at increased risk of cardiovascular side effects such as heart attack, stroke, chest pain, high blood pressure and abnormal heartbeat. Other possible side effects include headache, facial flushing, indigestion, dizziness, abnormal vision, and hearing loss. The best way to make sure your prescription drug is authentic is to buy it from a licensed pharmacy, with a prescription from your health care professional. Prescription drugs cannot be sold outside of a licensed pharmacy and should only be taken under the care of a health care professional because they are used to treat specific health conditions and may cause serious side effects.