NSF and Informed Choice Aren’t the Whole Story: What Supplement Testing Can Still Miss

If you shop for supplements long enough, you have probably been told to look for one of a few logos.

NSF Certified for Sport.

Informed Choice.

Third party tested.

And to be clear, those certifications can be useful.

They can help reduce the risk of banned substances, verify certain label claims, and provide an additional layer of quality control.

But I think the supplement industry sometimes makes a mistake when it treats those certifications as if they answer every question about product quality.

They don't.

A certification can tell you something important about a supplement.

It does not necessarily tell you everything you should want to know about that supplement.

That is an important distinction.

At Simply Good Supplements, our approach is pretty simple:

Don't just test enough to earn a logo. Test the things consumers would actually want to know.

That is why we use Light Labs to independently test our supplements and verify more than just whether a product might contain a banned athletic substance.

Let's talk about what supplement testing should actually look like.

TLDR: A Certification Logo Isn't the Same as Comprehensive Testing

NSF and Informed Choice can both provide valuable third party oversight, particularly for competitive athletes concerned about banned substances. But consumers should understand exactly what a certification does and does not prove.

• NSF Certified for Sport is a legitimate and valuable certification, particularly for athletes concerned about prohibited substances.
• NSF says Certified for Sport products undergo banned substance screening, formulation and label review, facility inspections, and ongoing monitoring.
• No certification can reasonably test every possible contaminant, adulterant, impurity, or quality problem that could exist in every supplement.
• A banned substance screen is not the same thing as confirming that every active ingredient is present at the stated dose.
• Testing for heavy metals is not the same thing as testing for pesticides, microbes, plasticizers, or other potential contaminants.
• Different ingredients require different analytical methods, so good testing should be based on the actual formulation rather than a one size fits all checklist.
• Consumers should ideally want verification of identity, potency, purity, and relevant contaminants.
• At Simply Good Supplements, we use Light Labs, an ISO 17025 accredited laboratory offering testing across active ingredients, heavy metals, microbes, pesticides, plastic related compounds, and numerous other categories.
• The goal isn't to criticize NSF or Informed Choice. The goal is to recognize that a logo should be the beginning of the quality conversation, not the end of it.

First, Let's Be Fair to NSF and Informed Choice

I want to make one thing clear before going any further.

This isn't an article arguing that NSF or Informed Choice are bad.

They're not.

For certain consumers, especially collegiate, professional, and tested athletes, banned substance certification can be extremely valuable.

NSF's Certified for Sport program, for example, screens supplements for hundreds of substances prohibited by major sporting organizations and includes formulation review, label verification, manufacturing oversight, and ongoing monitoring.

That matters.

If you're an athlete whose career could be jeopardized by an accidental positive drug test, reducing exposure to prohibited substances is obviously important.

But here's the mistake:

Banned substance testing and comprehensive product quality testing are not exactly the same thing.

And consumers often assume they are.

What Does NSF Certified for Sport Actually Test?

According to NSF, Certified for Sport includes several layers of oversight.

• Testing for prohibited athletic substances
• Formulation and label review
• Facility and supplier inspections
• Ongoing monitoring
• Verification against applicable NSF supplement standards

NSF also describes laboratory verification that can include label content, microbiological contaminants, heavy metals, and, depending on the formulation, other testing such as pesticides, residual solvents, protein, or caffeine verification.

That's substantial.

But notice something important.

The testing can be formulation dependent.

That makes sense.

You wouldn't run exactly the same analytical panel on a protein powder, herbal extract, creatine product, electrolyte formula, and multivitamin.

The problem isn't the program.

The problem is when consumers interpret the certification mark as:

"Every possible thing about this product has been tested and verified."

That's a much bigger claim.

No Testing Program Can Test for Everything

This is one of the most important things to understand about laboratory testing.

There is no single universal test called:

"Is this supplement clean?"

Laboratory testing is targeted.

You have to decide what you're looking for.

Want to know how much lead is present?

That's one analysis.

Want to know whether the product contains the stated amount of caffeine?

Different analysis.

Want to test for bacteria or yeast?

Different test.

Want to look for pesticide residues?

Different panel.

Want to test an herbal active compound?

Potentially another analytical method entirely.

This is why saying something is "third party tested" without explaining what was tested isn't particularly informative.

The better question is:

Third party tested for what?

What Can a Supplement Certification Potentially Miss?

This depends on the certification, the product, the ingredient, and the testing panel being used.

But there are several areas consumers should understand.

1. An Ingredient Can Be Present but Still Be Underdosed

Imagine a supplement label claims:

5 grams of Ingredient X.

The ingredient might genuinely be present.

But is there actually 5 grams?

Or 3.7 grams?

Or 5.4 grams?

Identity and potency are two different questions.

A quality testing program should verify not only that the correct ingredient is present but, when analytical methods make it feasible, whether the amount reasonably matches the label claim.

FDA dietary supplement manufacturing rules are built around this idea.

Manufacturers are expected to establish specifications for the identity, purity, strength, composition, and relevant contaminant limits of finished supplements.

That is a much more useful framework for thinking about quality than simply asking whether a logo is present on the bottle.

2. Heavy Metals Aren't the Only Contaminants That Matter

Lead.

Arsenic.

Cadmium.

Mercury.

These are probably the contaminants people hear about most often in supplements.

And they absolutely matter.

But contaminants can extend well beyond heavy metals.

Depending on the ingredients and manufacturing process, relevant testing might include:

• Microbiological contamination
• Pesticide residues
• Residual solvents
• Mycotoxins
• Plasticizers
• Bisphenols
• Undeclared pharmaceuticals
• Allergens
• Other process related contaminants

Light Labs, for example, offers analyses for heavy metals, pesticides, phthalates, glyphosate and AMPA, BPA, BPS and BPF, microbial contaminants, and numerous other analytes.

Does every supplement need every one of those tests?

No.

That's not the point.

The point is that testing should match the actual risks associated with the product.

3. Banned Substance Testing Is Not the Same as General Contaminant Testing

This is probably the biggest misconception among athletes.

A prohibited substance screen is primarily designed to answer a question like:

Could this supplement expose an athlete to substances prohibited by sporting organizations?

That's an extremely important question.

But it isn't the only quality question.

A product could theoretically pass an athletic banned substance screen and still have a different quality issue that wasn't part of that particular analytical panel.

For example:

• Does the creatine contain the stated amount?
• Is the caffeine dose accurate?
• Are heavy metals within appropriate limits?
• Are relevant botanical actives present at the stated levels?
• Is there microbial contamination?

Those are separate questions.

Good quality control asks all of them when appropriate.

4. "Third Party Tested" Can Mean Almost Anything

This is one of my biggest frustrations with supplement marketing.

A company puts:

THIRD PARTY TESTED

on the label.

Sounds impressive.

But what does it mean?

Maybe the product was tested for heavy metals.

Maybe one active ingredient was verified.

Maybe raw materials were tested but the finished product wasn't.

Maybe one batch was tested six months ago.

Maybe every production batch is tested.

Those are very different levels of quality assurance.

That's why consumers should look for companies willing to actually show what was tested.

At Simply Good Supplements, I would much rather show you the results than simply ask you to trust a badge on the bottle.

5. Testing Raw Ingredients Isn't the Same as Testing the Finished Product

This distinction is important.

A manufacturer might receive certificates of analysis from its ingredient suppliers.

That's useful.

But those ingredients still go through:

• Weighing
• Blending
• Flavoring
• Manufacturing
• Packaging

Those additional steps introduce opportunities for mistakes.

Maybe the wrong amount gets added.

Maybe blending isn't uniform.

Maybe contamination occurs during production.

Maybe the finished product no longer matches what the individual ingredient certificates suggested.

That is why finished product testing matters.

You ultimately consume the finished scoop.

Not the supplier's raw material.

6. A Certificate of Analysis Is Only as Useful as the Tests on It

A Certificate of Analysis, or COA, sounds authoritative.

And it can be.

But don't assume every COA is comprehensive.

A COA might include:

• Identity
• Microbiology
• Heavy metals
• Potency
• Or some combination of those

The useful question isn't:

"Does this product have a COA?"

It's:

"What does the COA actually show?"

That's the difference between marketing transparency and meaningful transparency.

What Should a High Quality Supplement Actually Be Tested For?

There isn't one testing panel that applies perfectly to every supplement.

But I think a good framework includes four major areas.

1. Identity

First question:

Is the ingredient actually what the company says it is?

That sounds obvious.

But ingredient identity is foundational.

FDA's current good manufacturing practice framework specifically requires procedures designed to ensure supplement identity, purity, quality, strength, and composition.

Before debating dose, purity, or efficacy, you need to know you're testing the correct ingredient.

2. Potency and Label Claim

Next:

Does the finished product actually contain what the Supplement Facts panel says it contains?

For a creatine product claiming 5 grams per serving, ideally you want verification that you're getting approximately that amount.

For caffeine:

Does the amount match the label?

For vitamins:

Are they present at expected concentrations?

For minerals:

Same question.

This matters because buying an evidence based ingredient doesn't help much if the formula doesn't contain the evidence based amount.

3. Heavy Metals and Relevant Contaminants

At a minimum, contaminant testing commonly includes the major heavy metals:

• Lead
• Arsenic
• Cadmium
• Mercury

But additional testing should depend on the formulation.

Botanical products may justify different testing than amino acid products.

Protein powders may present different considerations from creatine.

Plant derived ingredients may warrant pesticide or microbial testing.

There should be a reason behind the panel.

Not just a checkbox.

4. Microbiology

Supplements can also be evaluated for microorganisms such as:

• Total aerobic microbial count
• Yeast
• Mold
• E. coli
• Salmonella
• Other relevant pathogens

Again, risk varies by formulation.

But when microbiological contamination is a meaningful concern, testing should reflect that.

What About Adulterants?

This becomes especially important in certain supplement categories.

Historically, products positioned for areas such as weight loss, sexual enhancement, muscle building, or stimulant effects have faced particular adulteration concerns.

An adulterant screen can help identify undeclared pharmaceuticals, stimulants, or other compounds that should not be present.

Athletic banned substance panels overlap with part of this concern.

But depending on the product, a brand may decide to look beyond only athletic prohibited substances.

The right question remains:

What contaminants or adulterants are actually plausible in this category?

Then test accordingly.

Why Simply Good Supplements Uses Light Labs

This is where our approach differs.

We don't want our testing strategy to be:

What's the minimum we need to do so we can put a logo on the bottle?

I'd rather ask:

What would I personally want to know before I put this supplement in my body?

That's why Simply Good Supplements uses Light Labs for independent laboratory testing.

Light Labs operates an ISO 17025 accredited laboratory and offers hundreds of assays covering active ingredients, contaminants, elemental analysis, microbiology, pesticides, additives, and other testing categories.

That gives us the ability to build testing around the individual product.

Not every formula needs the exact same test.

That's actually the point.

We can look at the ingredients, the potential risks, and the claims we're making and test accordingly.

We Also Want Customers to See the Results

This is the other side of transparency.

I don't think consumers should have to email a company and hope someone sends them a PDF.

We've been working toward making our independent laboratory results easier to find directly on our product pages.

Where testing is available, you'll see information showing what was tested and how the product performed.

That is the standard I would like to see become more common in the supplement industry.

Don't just tell consumers:

"Trust us. It's tested."

Show them.

Does This Mean NSF Certified for Sport Isn't Worth It?

Absolutely not.

For certain athletes, it can be extremely valuable.

If you're subject to drug testing through a professional league, NCAA competition, international federation, or another organization governed by anti doping rules, a recognized banned substance certification can provide an additional layer of protection.

NSF Certified for Sport is specifically designed around that issue and is recognized or recommended by numerous professional sporting organizations.

That is a legitimate benefit.

What I don't think consumers should do is take that benefit and turn it into:

"This must therefore be the cleanest, most accurately dosed, most comprehensively tested supplement available."

Those are different claims.

Certification and Comprehensive Testing Can Complement Each Other

This shouldn't be framed as:

NSF versus independent laboratory testing.

Or:

Informed Choice versus a COA.

The better approach is understanding what each layer tells you.

A good certification program can provide manufacturing oversight and prohibited substance screening.

Independent finished product testing can provide additional information about specific active ingredients and contaminants.

Transparent COAs allow consumers to see the evidence.

Together, those approaches can create a much more complete picture.

What Should Consumers Ask Supplement Companies?

Here's the simplest way I can put it.

Don't just ask:

"Is it third party tested?"

Ask:

• What did you test?
• Was the finished product tested?
• Were the active ingredients verified?
• Were heavy metals tested?
• What other contaminants were appropriate for this formulation?
• Was the batch I purchased represented in that testing?
• Can I see the results?

Companies should be able to answer those questions.

And if they can't, a giant "THIRD PARTY TESTED" badge shouldn't automatically make you feel better.

The Bigger Problem With Supplement Testing

I actually think the supplement industry has created some of its own confusion here.

Testing has become a marketing claim.

Instead of explaining what quality testing means, brands throw logos onto labels because logos are easy.

Consumers then understandably begin treating those logos as shortcuts for quality.

But supplement quality isn't binary.

A bottle isn't simply:

Tested.

or

Not tested.

There are levels.

There are different analytical methods.

Different contaminants.

Different ingredients.

Different manufacturing risks.

Different batches.

The goal should be to build a testing program that actually makes sense for the product.

The Bottom Line

NSF Certified for Sport and Informed Choice can be useful.

Especially if you're a drug tested athlete.

But they're not magic shields.

And they shouldn't stop you from asking deeper questions about the product you're buying.

At Simply Good Supplements, our philosophy is pretty straightforward:

We want to test what actually matters.

That means looking beyond only banned substances.

It means evaluating active ingredients when appropriate.

It means testing for relevant contaminants.

It means looking at heavy metals.

It means using finished product testing.

And it means giving consumers access to the results.

That's why we use Light Labs to independently test our products.

Light Labs gives us access to an ISO 17025 accredited laboratory and a broad analytical testing menu that allows us to match testing to each individual formula.

The goal isn't to collect the most logos.

The goal is much simpler.

What's on the label should be in the bottle.

What's not supposed to be in the bottle shouldn't be there.

And you shouldn't have to take our word for it.

References

1. NSF. Certified for Sport Program. NSF International.
2. NSF. Product and Ingredient Certification. NSF International.
3. NSF. Certified for Sport Certification Process. NSF International.
4. U.S. Food and Drug Administration. Backgrounder on the Final Rule for Current Good Manufacturing Practices for Dietary Supplements.
5. U.S. Food and Drug Administration. Questions and Answers on Dietary Supplements.
6. Light Labs. Supplement Testing Solutions.
7. Light Labs. Testing Menu and Turnaround Times.