An unauthorized "fat burner" sold online can pose serious health risks, Health Canada warns.

"West Pharm Therma Lean Fat Burner Energizer contains ephedrine and caffeine, which combined together, may cause serious and possibly fatal adverse effects," Health Canada said Wednesday.

Canadians suffering from heart conditions, high blood pressure and diabetes are among those particularly at risk.

Nutrition First of Nova Scotia distributed the product across Canada through the internet.

After Health Canada sent the company a letter advising it to cease the sale and advertising of the product, the company agreed to remove the product from the market and has closed down its website.

Taking Ephedrine together with caffeine can cause symptoms ranging from dizziness, tremors, headaches and irregularities in heart rate, to seizures, psychosis, heart attacks and stroke, Health Canada said.

The department advised customers who bought the product to consult a medical professional if they have used it or have concerns about their health.

The Canada Border Services Agency and Health Canada are working to stop future imports of the product from entering the country.

Since 2005, Health Canada has warned several times about the risks associated with products that contain the herb ephedra or ephedrine either alone or in combination with stimulants for weight loss, body building or increased energy purposes.

Use of products containing ephedrine is not recommended in people with heart problems, hypertension, thyroid disease, diabetes, enlarged prostate, anxiety and restlessness, glaucoma and pheochromocytoma, serious gland disorder, because ephedra/ephedrine aggravates these conditions.