Buyer beware: People should not take this slimming product which contains undeclared drug ingredients.

People should not buy or take a slimming product in the form of dark brown capsules packed inside a blister pack labelled as "Beautiful", the Department of Health says, noting it contains the undeclared drug ingredients phenolphthalein and sibutramine.

The department received a report from the Hospital Authority about a suspected poisoning case involving a 23-year-old woman who had taken the product for more than a year.

She had become mentally disturbed for several months before she was admitted to Yan Chai Hospital on June 3. She was discharged the next day after her condition improved.

Phenolphthalein is used for treating constipation but has been banned for its cancer-causing effect.

Sibutramine is a Western medicine used as an appetite suppressant for slimming. Its side effects include increased blood pressure and heart rate, and mental disturbance, and possible convulsions. People with heart problems should not take it.

Products with sibutramine must be registered before being sold on a doctor's prescription and dispensed under a pharmacist's supervision in Hong Kong.