Consumers who use Optimum Health Care SleePlus TCM or BYL SleePlus are being warned that the sleep supplements could be addictive when used continually over a period of a few months, Health Canada says.

The federal agency said in an advisory issued Thursday that the sleep aids, which have not been authorized for sale in Canada, contain the drug clonazepam. Patients should only take products containing clonazepam under the supervision of a health-care professional.

Optimum Health Care SleePlus TCM products were sold through the Vancouver clinic Optimum Health Care. BYL Pharmaceuticals Ltd. distributed its BYL SleePlus products to other retailers. Both packages were labelled with Chinese script.

Consumers should talk to a health-care professional before they discontinue use of the sleep aids and return the products to the retailer.

Side-effects of the drug include dizziness, drowsiness, confusion, depression, loss of memory and hallucinations.

No adverse reactions linked to the use of the products have been reported in Canada.

Consumers with questions can call Health Canada at (613) 957-2991, or toll free at 1-866-225-0709.