Health Canada is telling people not to consume certain batches of Royal Medic No.1 Chinese Caterpillar Fungus, which could be contaminated with microbes.

Royal Medic No. 1 — promoted as a health tonic — is not authorized for sale in Canada, but some Canadians may have brought it home from foreign travel or bought it over the internet, Health Canada said Wednesday in a foreign product alert.

The warning came from the Hong Kong Department of Health, which has advised the public not to buy or use three batches of the proprietary Chinese medicine (lot numbers RM 630021, RM 630023 and RM 6300026) due to microbial contamination, Health Canada said.

"Microbiological contamination of health products can pose a risk to human health and may cause a variety of adverse effects, including bacterial infection," the federal department said. "Children, pregnant/nursing women, people with weak immune systems, and the elderly have potentially a higher risk of bacterial infection."

So far, however, no adverse reactions suspected to be associated with the product have been reported in Canada, it said.

In another alert issued the same day, the department urged people not to use Steripaste Medicated Paste Bandages with batch numbers 07085930, 07085932 or 07085673.

"This product may not be sterile, so there is a possibility the bandage may cause a wound infection," it said.

The British-made bandages, not sold in Canada, are used for the treatment of ulcers, particularly chronic leg ulcers, it said.