Skip to main content

The Globe and Mail

Use common sense to avoid risky supplements, researchers say

Ridvan Arda/Getty Images/iStock

Consumers should not rely solely on government regulators to protect them from unsafe dietary supplements. Instead, they should also use their own common sense to avoid potentially dangerous products in the marketplace.

That is the conclusion of researchers at Toronto's St. Michael's Hospital who have just completed an analysis of unsafe products recalled by the U.S. Food and Drug Administration.

They focused their attention on Class l drug recalls – the most serious type of recall, involving products that could pose a risk to human health.

Story continues below advertisement

Of the 465 Class 1 drug recalls from 2004 to 2012, 51 per cent were dietary supplements. And the majority of these risky supplements were in the categories of weight loss, bodybuilding and sexual aids.

"There are all sorts of things that could be in these products," said Muhammad Mamdani, one of the authors of the study, published this week in the JAMA Internal Medicine journal. "Some contained steroids, others might have traces of prescription drugs that should not really be given over the counter. …

"This study should serve as a reminder that dietary supplements, and products you feel are safe because they are 'natural' or don't require a prescription, may not be safe after all."

Although the study is based on the U.S. market, the researchers say Canadian consumers face similar risks. Many of the products are available in both countries. The team decided to use U.S. figures because "the data is pretty accessible" from the FDA, Mamdani explained. "In Canada, the data is a bit harder to get at."

Unlike pharmaceutical products, dietary supplements do not go through a long approval process before being sold to the public. According to the FDA's definition, these supplements include products taken orally that contain a dietary ingredient, such as vitamins, minerals, herbs and other botanicals, amino acids or metabolites.

In the United States and Canada, supplement manufacturers are suppose to use current good manufacturing practices (CGMP) "to ensure quality throughout the manufacturing, packaging, labelling and storage of these products," the researchers note in their paper.

"Despite these safeguards, dietary supplements adulterated with pharmaceutical compounds have continued to enter the marketplace. Their use may expose unwitting consumers to potential harm," they warn.

Story continues below advertisement

"For example, 'natural' products for sexual enhancement can actually contain prescription drugs like Viagra," Mamdani said.

"And it is not incredibly uncommon to have a 'natural' bodybuilding product contain steroids," he said. Long-term use of steroids can lead to mood fluctuations and organ dysfunction.

The biggest challenge facing government regulators is the large number of supplements – about 65,000 in the United States. It is impossible to keep tabs on them all, he said. In fact, a report from the U.S. Auditor-General found that the FDA lacked accurate contact information for 20 per cent of the manufacturers involved in product recalls.

In Canada, supplements are regulated by Health Canada under the Natural Health Products Directorate. And there are some differences between Canada and the United States in terms of the regulations, noted Blossom Leung, a media relations officer with Health Canada.

"Products that are classified in the U.S. as dietary supplements can be considered drugs, natural health products or other regulated products in Canada, depending on the ingredients and health claims," Leung explained in an e-mail.

"To be sold in Canada, natural health products (NHPs) must undergo pre-market review to ensure that they meet the requirements of the Natural Health Products Regulations (NHPR) pertaining to the safety, efficacy and quality of products. The NHPR came into force on Jan. 1, 2004, and establishes the requirements for the manufacture, packaging, labelling and importation of NHPs for their sale in Canada."

Story continues below advertisement

Even so, Mamdani thinks that Canadian regulators, like their U.S. counterparts, lack the resources to adequately monitor the market. "We would have to put in a lot more money and resources … to the point where I am just not even sure it is feasible," he said.

"We have to take responsibility on ourselves to be a bit more diligent," he said. That could mean not being swayed by a "natural" label or resisting the temptation to buy unvetted products over the Internet. Mamdani urges patients to talk to their doctors to see if they need supplements.

Report an error Licensing Options

The Globe invites you to share your views. Please stay on topic and be respectful to everyone. For more information on our commenting policies and how our community-based moderation works, please read our Community Guidelines and our Terms and Conditions.

We’ve made some technical updates to our commenting software. If you are experiencing any issues posting comments, simply log out and log back in.

Discussion loading… ✨

Combined Shape Created with Sketch.

Combined Shape Created with Sketch.

Thank you!

You are now subscribed to the newsletter at

You can unsubscribe from this newsletter or Globe promotions at any time by clicking the link at the bottom of the newsletter, or by emailing us at