an assortment of supplements

How to Find Reliable Information on Supplements

Do you use vitamins, minerals, herbal remedies, or other supplements? If so, you’re not alone. About three-quarters of Canadians and Americans do!

How can you be sure that they won’t land you in the hospital or end up being a waste of your hard-earned dollars?

You might be surprised to learn that supplements are abysmally regulated. They’re a big business, worth an estimated $177 billion globally (!) in 2023, and lobbying efforts have hamstrung agencies like the US Food and Drug Administration (FDA) and Health Canada. 

So where can you go for reliable information on these products, to help you make safe and sensible decisions? Let’s take a look.

Where not to start: A pharmacy

When you see the long line of products for sale at the drugstore, would you be curious about products with names like Cardio-this or Heart-that?

You might pull one off the shelf and read what it says on the package. You’d probably assume, reasonably, that you could trust that information, that it’s regulated like over-the-counter medications such as Tylenol and Pepcid, stocked nearby. 

Not so much. 

If you’re in Canada… 

“Natural health products” (NHPs), as the regulations call them, do have to demonstrate effectiveness and safety before being licensed by Health Canada for sale. You can check that by looking for a natural health number (NPN) on the package. (Get a magnifying glass.)

a bottle of coenzyme q10 showing the natural product number (NPN)

BUT… a 2021 Auditor General’s report found that Health Canada did little to check “whether product labels and advertising contained misleading information” or even “ensure that products were as described on the label”.

The Auditor General’s team looked at a sample of 75 products licensed by Health Canada. Just over half of them had “misleading label information,” including unauthorized health claims.

So NPN number or not, buyer beware.

In the USA…

The situation is worse, because supplements don’t even need to be approved by the FDA to be sold at pharmacies or online. 

While the FDA can take legal action if companies make false or misleading claims, or if their products are found to be unsafe, often they just request a voluntary recall or issue a public notification. And that happens only after a suspect product has been sold and used by unwitting consumers.

And as Consumer Reports puts it: “…prescription drugs used to treat cancer and other diseases are standardized, with each dose containing the exact same quantity of active ingredients… Such standardization is not mandatory for supplements in the U.S.”

But they’re natural. How harmful can they be?

Health Canada says that while natural products are generally safer than medications, they’re not without risk. Here are just a few examples:

  • A 2015 study found that supplement use led to about 23,000 emergency room visits a year in the US (!), most due to heart problems related to weight loss and energy boosting supplements.
  • Researchers estimate that one in five cases of liver damage in the US are caused by supplements, mostly weight loss products containing green tea extract, bodybuilding products containing anabolic steroids, and “multi-ingredient nutritional supplements”.

Green tea extract! Who would suspect?

  • When Consumer Reports analysed 16 echinacea and 13 turmeric products, they found problems in over a third of them, “including elevated levels of lead and bacteria, as well as low levels of key active compounds.”

Read that again. Lead! Not good.

  •, an organization that analyzes and certifies supplements, reports that one in four botanical supplements fails its testing, due to “bacterial or heavy metal contamination or because they don’t contain what’s listed on the label”. 
  • Researchers at the University of Guelph similarly found that more than half of herbal products they looked at contained ingredients not on the label, including fillers, cheaper alternatives, and plants that have known toxicity, side effects or “interactions with other herbs, supplements and medications”.
  • And between 2007 and 2016, the US FDA found 776 supplements with unapproved pharmaceutical ingredients added to them. (Most were products promoting sexual enhancement, weight loss, or muscle building, so you probably don’t have to be afraid of your vitamin D.)

I could go on, but you get the idea.

So what can you do?

Go online to “research” the products?

As you probably know, the internet is pretty much the Wild West. That Canadian Auditor General’s report found that 88% of sampled NHPs were advertised online with misleading product information. (88%!)

Online retailers like Amazon,, or aren’t routinely monitored by the FDA or Health Canada, so claims you see there may not be quite the whole picture. Side effects, safety considerations, and medication interactions don’t always get the prominence they deserve.

For fun, I searched for heart supplements on, one of the top results (sponsored) was Strauss Naturals Heart Drops, which are licensed by Health Canada (NPN 80030089). The label says it “helps support a healthy cardiovascular system.” What does that mean exactly? 

I looked at the summaries of evidence from the US National Institutes of Health (NIH) for each of the ingredients. They say: 

  • Garlic: “evidence is inconsistent” for a possible small reduction in cholesterol and “evidence is limited” for possibly helping with high blood pressure.
  • Hawthorn: “conflicting evidence” for heart failure.
  • No mention of cardiovascular evidence for any of the other ingredients. 
  • No evidence of the “calming effects” claimed on the Amazon sales page. Haha. I love how they just threw that in.

Never mind if the form (“aged garlic bulb”?) and amount of the ingredients is the same as what was used in the most promising studies. Never mind if this particular combination has ever been studied. Never mind that the evidence is kind of dodgy.

And there’s no mention of side effects. (For example, side effects of hawthorn can include dizziness, nausea, and digestive symptoms.)

Personally I’d expect more of something claiming to “support a healthy cardiovascular system”. Would you send them $82.99?

I’d be wary of anyone selling supplements. That includes chiropractors, naturopaths, and even medical doctors. (I’m thinking of certain online MDs.) Not that everyone is dishonest, but there’s very little oversight, and the incentive is to sell, sell, sell. What’s the harm?

There are some trustworthy independent websites though.

Two reliable online sources

Instead of a Google search, go directly to one of these two sites: 


MedlinePlus describes itself as “a service of the National Library of Medicine (NLM), the world’s largest medical library, which is part of the National Institutes of Health (NIH).”

It’s a great place to learn about health topics in general, and the Herbs and Supplements listing gives you good information from various sources, including the NIH’s National Center for Complementary and Integrative Health (NCCIH) and Office of Dietary Supplements (ODS).


Examine is for if you want to go deeper. The organization has no ads or industry ties. They pay the bills by charging for more in-depth content.

You’ll find well-written, detailed and referenced summaries of the studies behind countless vitamins, herbal remedies, and other supplements. 

You can also search by condition, such as high cholesterol, or categories, like cardiovascular health. If you find this stuff interesting, prepare to go down a rabbit hole.

How to know what brands to trust?

Neither of those two sources make recommendations about specific brands. (Wisely.)

So if you’ve decided to take a natural product, how do you know that that particular brand is safely manufactured and accurate about exactly what’s in the bottle?

The best way to be sure is looking for certifications from independent organizations like NSF International, US Pharmacopeia, Underwriters Laboratory, and ConsumerLab.

US Pharmacopeia seal
US Pharmacopeia seal

Unfortunately, I haven’t been able to find these seals on Canadian products. When I reached out to several major brands, the collective answer was something to the effect of, “Trust us, we’re very high quality.”

Again, probably they are, but it would be nice to have independent verification. 

In Canada, the best you can do is look for that Natural Product Number (NPN), which tells you at least that the product is licensed by Health Canada. It’s not a guarantee, but it’s better than being unlicensed. 

In the US, look on the package for seals from those organizations above. Or go to their websites, which I linked to above. You can also go to the FDA’s eye-opening product recall page, to make sure your supplement isn’t there. 

(Health Canada has one too, but you have to type in the name of a product to see if there is a recall or advisory for it.)

And watch out for meaningless stamps or seals. For example, this vitamin D has a “360 pure” seal, which is something they award themselves for having good manufacturing practices. Their products are probably fine, but it’s not independently audited. 

Not a third-party (independent) seal

Always keep your healthcare team in the loop

Finally, of course, your doctor or other primary care provider needs to know what supplements you’re taking, and they can advise you on the ins and outs of anything you’re considering. 

But with so many products on the market, realistically, physicians won’t have the lowdown on all of them. So you may want to also check with a pharmacist, registered nurse, or dietitian, depending on who you have that you trust. They may have knowledge or more time to research for you. 

Or they may not. When Consumer Reports sent secret shoppers to talk to ten drugstore pharmacists in the US, most “weren’t familiar with potential risks for the supplements on their shelves and rarely warned customers about problems such as interactions with prescription medications.” 

But a few did! So you might as well ask. 

Pharmacists, registered nurse and dietitians, and of course, physicians, are regulated professionals, bound to give honest, evidence-based guidance to patients. 

On the other hand, I’d be wary of supplement advice from naturopaths. Despite appearances, they aren’t medical doctors, and they tend to be much more bullish about natural remedies than the evidence supports. 

For example, a review of 53 websites of naturopathic clinics in Canada found that the treatments most commonly advertised are “viewed by the scientific community to be of questionable value and have no scientific evidence of efficacy beyond placebo”. 

Unfortunately, for many natural products, there just isn’t enough high-quality research done, so no one can give you a firm answer.

Knowledge is power

Bottom line: If you’re curious about any supplements, start with the summaries on MedlinePlus or dive deeper with Examine if you like. It takes a tremendous amount of time and expertise to dig through and evaluate individual studies, so let these independent reviewers do the work for you. 

And like I said above, if you decide to take a supplement, even something that seems as harmless as iron or vitamin E (they’re not), make sure your doctor and other healthcare providers know, in case there are safety concerns, side effects, or medication interactions you’re not aware of.

Comments welcome

I’d love to hear from you on this. Where do you go for trustworthy information on supplements?

What did you find when you looked in your medicine cabinet? Did any of the supplements have a NPN or a seal from NSF International, US Pharmacopeia, Underwriters Laboratory, or ConsumerLab?

Did you find anything interesting on MedlinePlus or Examine?

Comment on Facebook and we’ll chat there. 

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