How To Buy Good Quality Supplements

What to look for on the label: USP seal, ingredients, milligrams

What to look for on the website: third party testing, scientific studies

Reputable brands: Pure Encapsulations, HerbPharm, Gaia, BioKult

Stepping into the supplement aisle can be overwhelming! Take magnesium – there are multiple different types (glycinate, threonate, citrate …), multiple different forms (powdered, capsule, liquid …), and multiple different brands to choose from. 

The problem with supplements

In the US, supplements are not regulated. At all! In Europe and many other countries, supplements are regulated as foods and are not held to the stricter standards of medications.

In the US especially, this means that you really don’t know what’s in your supplements. Scary!

One study from 2013 showed that 60% of supplements in the US contained ingredients they weren’t supposed to. Sometimes, they contained common allergens like nuts or wheat. Sometimes they didn’t even contain the active ingredient(s) at all!

Several studies since 2013 have shown that this is not a problem of the past – companies continue to have little to no repercussions if they fill their supplements with mystery ingredients.

The good news

This is not to scare you out of using supplements forever! But it goes to show how important it is to choose brands that make safe, accurately-labeled supplements.

Luckily, several companies have made it their mission to hold themselves to a higher standard. There are things you can look for to make sure the supplement you choose:

  • contains the ingredients it says it does
  • contains the amounts of those ingredients it says it does
  • is made in a safe, clean facility

Let’s run through what makes a supplement a good choice and warning signs that should make you run the other way. I’ll also provide brand recommendations (ones I use personally, not sponsored!) at the end if you don’t want to do your own digging.

Ingredients and Milligrams

This may seem basic, but when you’re buying a supplement it’s important that it tells you what’s inside it. If a product is a “proprietary blend”, this is a red flag for me. 

Proprietary blends mean you don’t know what you’re putting in your body – to me, that’s scary! I make rare exceptions with proprietary blends if they are well tested, although this is not common. 

In general, stick to products that come with a list of ingredients as well  as a milligram/other unit next to each active ingredient on the “supplement facts” label.

The GMP Seal

You may see many supplements with a GMP seal, which stands for Good Manufacturing Process. While this is a good thing, all supplements (in the US) are expected to comply with these standards. There is no official seal, and having a GMP seal does not mean the supplement has gone above and beyond. It also does not mean that the company has actually complied with GMP standards.

Good Manufacturing Processes are put in place to ensure that supplements have what they say they do in them and aren’t contaminated – but these requirements are not enforced. This is why it’s good to look for other things that tell us the supplement is safe.

The USP Seal

The USP, or United States Pharmacopeia, is a seal created by the U.S. Pharmacopeial Convention, a nonprofit organization created to make up for the government’s lack of supplement oversight. If a supplement has a USP seal, it means it has been evaluated by this organization for purity, potency, and quality. Companies are not required to go through this evaluation process, so a USP seal is a sign of a company’s true commitment to safety and accuracy.

There are international equivalents to this seal such as BP (British Pharmacopeia), EP (European Pharmacopeia), and JP (Japanese Pharmacopeia). 

In Australia?

Australia has a bit of a different system in which supplements are regulated by the Therapeutic Goods Administration (TGA) depending on their classification as a food or a drug. All supplements regulated by the TGA are required to have an ‘AUST’ number on the label. 

If you don’t see this label, it’s a sign the supplement is not required to be regulated and may have questionable quality.

Third Party Testing for Purity

Some supplements state on their labels or websites that their product is “third party tested”. This means that the company has paid for a laboratory (unaffiliated with the company itself) to test the contents of their product. Doing this makes sure that the product:

  • Contains what it says it does in the amounts it says it does
  • Is not contaminated with allergens, heavy metals, or other unlabeled ingredients

When buying supplements, I personally prefer to choose ones that do third party testing. To me, this is a step above and beyond what most companies do and is a sign of a quality brand. 

Most companies will provide the results of testing, either directly on their website or if you email them requesting a copy. 

Clinical Trials

Now this is something I really love to see, especially in products that are new and exciting (one that comes to mind is a probiotic called BioKult Migrea). When a product has clinical trials backing it up, this is a little bonus that tells you there’s some good science behind the product.

One caveat here – if the study was funded by the company itself, you can take it with a grain of salt. There is always some level of bias involved in research, but imagine doing a study on your own product! You’re certainly going to hope it works and will inevitably look for signs that it does (rather than simply looking at what the research is saying).

Most supplements studied in a clinical trial will say so on their website, as this is something to be proud of. You can also email the company and ask them directly.

My favorite brands:

  • BioKult probiotics
  • Pure Encapsulations
  • HerbPharm
  • Gaia
  • Integrative Therapeutics
  • Solgar
  • Douglas Labs

I’m not sponsored by any of the above supplements – they are brands I use personally and/or recommend to my 1-on-1 clients. 

When in doubt, ask your doctor or dietitian for help!


DNA barcoding detects contamination and substitution in North American herbal products

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