Unsafe drug: Consumers should avoid slimming product Ener Day which contains an undeclared drug ingredient.

Consumers should not buy or use slimming product Ener Day which contains an undeclared drug ingredient with potentially serious side effects.

The Department of Health said a 21-year-old woman who took the product was admitted to Caritas Medical Centre in July after losing consciousness. The product was supplied by a slimming centre called Perfectshape in Tuen Mun.

Tests found the product contained sibutramine which can increase blood pressure and heart rate. It must be registered with the Pharmacy & Poisons Board and can only be sold on a doctor's prescription and under a pharmacist's supervision.

The department has ordered the centre to recall the product.

People using the product should stop taking it and see a doctor if they feel unwell. Call the slimming centre on 2359 3882 for more information on the recall.