Safety advice: People should not buy or use Lexscl Fat Rapid Loss capsules, which contain ingredients that can cause side effects.

The Department of Health warns consumers not to buy or use Lexscl Fat Rapid Loss capsules, which contain undeclared Western drug ingredients that can cause side effects.

A 21-year-old woman who had taken the product, bought online, for two weeks sought medical treatment from Tuen Mun Hospital on February 16 because of hand tremors and heartbeat concerns.

The department checked samples of the product and found it contained sibutramine and thyroid hormones. Sibutramine is an appetite suppressant. As it can cause increased blood pressure and heart rate, people with heart problems should not take it. Thyroid hormones are used for the management of hypothyroidism. Known side-effects include hand tremors, subnormal activity of the thyroid gland, excessive sweating, headache and insomnia.

Products containing these drug ingredients can only be sold on a doctor's prescription and under supervision by a pharmacist.

The department has no record of the product having been imported into Hong Kong for sale or submitted for registration. The manager of the internet auction site concerned has been asked to remove the product.

People who have been using it should stop immediately and seek medical advice. The product should be disposed of.

Weight control should be achieved by good diet and appropriate exercise. People should consult their doctors before using any drug for weight control.