Health alert: Sweet Energizer Vitality Candy contains an undeclared drug analogue.

People should not buy or use a product named Sweet Energizer Vitality Candy which contains an undeclared drug analogue that can cause serious side effects, the Department of Health says.

A product sample recently obtained from a retail shop showed the presence of aminotadalafil, an analogue of tadalafil which is usually used for treating impotence.

The distributor has been ordered to recall the products and retailers asked to remove them from shelves.

Tadalafil's side effects include low blood pressure, headache, vomiting, dizziness, and vision disturbances. It can interact with nitrates found in some prescription drugs and lower blood pressure to dangerous levels.

Aminotadalafil's chemical structure is similar to tadalafil. Tadalafil analogues may have the same side effects as tadalafil and pose a similar threat to consumers.

Products containing tadalafil must be registered before sale and can only be sold on a doctor's prescription and under a pharmacist's supervision.