A labelling deadline means many homeopathic medicines will not be sold in Canada. (Associated Press)

Hundreds of natural health products could disappear from store shelves next spring because of a Health Canada backlog in approving licences, warns the Canadian Health Food Association.

"We're at a critical stage," said Carl Carter, director of regulatory affairs and policy development for the CHFA.

"The biggest concern we have at this point is the standards of evidence Health Canada has been requesting for products' efficacy," he told CBC News.

Firms that make and sell natural health products are not opposed to being regulated. In fact, they welcome the Health Canada stamp of approval, said Carter. However, he said the "pendulum has swung too far" in terms of proving that a drug works.

The licensing has been underway since January 2004, when Health Canada announced it would regulate natural health products. As of April 2010, all natural health products will need an NPN, natural product number, to be sold.

However, the licensing process has become bogged down, and Carter said it's partly because Health Canada has set the bar too high.

Health Canada faces licensing backlog

Since 2004, 41,828 products have been submitted to Health Canada for licensing. So far, 15,784 product licences representing 20,674 products have been issued.

Another 834 applications have been recommended for a licence and are awaiting administrative completion.

Carter said part of the problem was something he called "pharmaceutical creep," where the same stringent standards that are applied to pharmaceutical products are applied to natural health products.

Natural health producers today are being asked to supply double-blind studies and human clinical trials to back claims made on the labels, even when safety has been established, he said. It's a very expensive requirement for small- to medium-sized firms.

"Back in 2004 some products were approved very quickly, but if the same applications were made in 2008 or 2009, they might not have gotten their licence," said Carter.

New Brunswick pharmacist John Staples said he'll have to stop selling several herbal and homeopathic medicines in April — not because they're unsafe but because the producer considers Canada too small a market to invest in the licensing procedure.

'Crazy' standards, says N.B., pharmacist

He expects herbal and homeopathic medicines to be the most affected and says it's "crazy" for Health Canada to apply the same standards to both pharmaceuticals and natural health products.

"Pharmaceutical drugs are far more potent and just a slight deviation in dosage can be dangerous," said Staples, whose Moncton pharmacy Staples Drugs, has sold both types of drugs for 40 years.

"A doctor can prescribe the arthritis drug Celebrex for you, but it can also cause a heart attack," he said as an example. "With homeopathic drugs, you can take 10 times the dosage and there's no problem."

Another issue the CHFA has with Health Canada's procedure is the sheer number of products that were rejected for licensing. Just over 36 per cent of natural health products were refused. There was little feedback and no chance for negotiation.

Health Canada is not allowing any "may" claims. For instance, a label cannot say the product "may" do something. In Health Canada's eyes, it either has an effect or not.

Health Canada recognizes the process has slowed and said it is taking steps to speed things up.

According to a spokesman, the department has streamlined the current review practices and has introduced electronic tools.

It also held technical workshops across Canada for more than 350 applicants recently.