Health alert: Consumers should avoid Power 58 as it contains a potentially hazardous ingredient that can cause side effects.

The Department of Health warns consumers not to buy or use six brands of health products that contain acetildenafil, which can cause side effects.

The products are Power 58, Platinum Power 58, Ehanix, Jolex, Onyo and Deguozonghengtianxia.

Acetildenafil is a chemical with a similar structure to sildenafil. The latter is a Western drug ingredient used for the treatment of erectile dysfunction. Its side effects include headaches, flushing, hypotension and transient vision disturbances. Products containing it are 3rd Schedule poisons under the Pharmacy & Poisons Ordinance. It should only be sold on a doctor's prescription and under the supervision of a pharmacist.

People who have been using the products should immediately stop and seek medical advice.