health supplement testing

How Product Testing Works In The Supplement Industry

health supplement testing

The supplement industry has a reputation as the uncouth, red-headed stepchild of the pharmaceutical industry.  They both make their money by convincing you to swallow things, but unlike pharma, supplements released onto the market don’t have to go through clinical trials to see whether or not taking them will cause your testicles to develop male-pattern baldness or other such weird things.


We might as well throw our vitamin D capsules in the trash before our sperm count goes the way of Hiroshima, right?

Well………if you’re snacking on spirulina that’s been irradiated in the south pacific then yes you probably should…..sorry.  Just make sure you do it soon so your fertility doesn’t take a bath in Crater Lake.

But otherwise you should be fine.

But more importantly,  you ought to know that the supplement industry does indeed have its own set of guidelines that it has to follow with regards to product safety.

The good news is that the guidelines, if properly followed, are adequate to ensure things are what they say they are and prevent an explosive clostridia outbreak from inoculating in your whey protein while it sits in your cupboard.

The bad news is that most people in the industry don’t have a great working understanding of how these verification methods work, even though they deal with test results all the time.

The Certificate of Analysis:  Does the Emperor Have Clothes?

The standard unit of documentation in quality control is the Certificate of Analysis.  It’s a piece of paper that lists the battery of test results performed on a substance to prove its quality.

This is an example of one I have from a supplier for 5-HTP:

certificate of analysis


Collectively these test results aim to quantify the following components of product quality:

  • Contamination:  Does the product contain excessive amounts of heavy metals or microbes?
  • Identity:  Is the ingredient what it says it is?  (This is more important than you might think because there’s a cottage industry built around spiking ingredients with less expensive substitutes that are hard to detect).
  • Concentration:   Does the ingredient exist in the amount specified?

The logic is that if you can verify these three things you’re not getting hoodwinked.

C of A’s are tossed around as proof that something is pure, pristine, and rapturously intersected between science and nature.

That is true in theory, except for an Al-Gore sized inconvenient truth:  lots of people don’t double check the results.

 A C of A gets made at a lab in China, gets shipped across the Pacific until it comes to harbor at the City of Industry in California, makes its way onto the desk of the QC analyst at a distributor, gets gleefully passed along to a manufacturing rep before the product is ordered, and then is finally waived like a flag to nubile retailers as proof that everything’s A-Okay in nutraceutical land.

This farm-to-pill process often takes place on pure faith.

I’ve been at conferences where people in charge of quality control nakedly admit to the crowd that they have no idea whether or not their suppliers are making up numbers on their C of A or not.  Each incoming batch looks exactly the same, except a few numbers to the right of the decimal point move up or down.

Now before you run away in horror and light your canister of Incredible Greens on fire let me reassure you that in my experience with product testing things are usually fine.  Mistakes do happen but this is the exception, not the rule.

Your garden variety manufacturing rep has a grandma too and he’d hate going to bed at night knowing he was complicit in the adulteration of her anthrax-laced multivitamin.

But in a world with many ingredients, chaotic weather patterns and complex patterns of trade how can you, dear nutraphile, be sure product quality is what it’s supposed to be?

It’d behoove us to understand how these verification processes work.

The ABC’s of Testing

Here’s a quick shakedown of the different tests that are performed on dietary supplements:

Contamination:  Microbes, heavy metals

Identification:  organoleptic, UV-Vis, FTIR, NIR, TLC

Concentration:  HPLC, Mass Spectometry, LC-MS

Zowee!  What a clusterf***** alphabet soup of daddy-knows-what, right?

If the idea of sifting through the details of the HYIC-XYZ-123 testing protocol gives you a migraine……relax.

We’re going to get through it, and it’ll be fun.  We just have to close our eyes and take the plunge.







Most people don’t want a side-serving of botulism with their African mango extract.  I doubt that’s the “miracle” they have in mind when they talk about its weight loss capabilities.  To avoid the presence of unwanted toxins and other nasties you must test all final products for contaminants.

The two tests that are required are heavy metals and microbes.  You can test for the presence of pesticides, solvents and other residual stuff as well but that’s only if you want extra credit.

If you’re a path-of-least-resistance kind of guy and just want to avoid getting a nastygram from the FDA then microbe and heavy metal testing will suffice.


Microbe tests have been around forever and are pretty straight forward.  If you ever took a microbiology class they’re not all that different from those lab experiments where you grew a bacterial colony on a petri dish and then determined  size by measuring how big it was.

A microbe test works the same way:  get a sample of the product, dilute it in some sort of broth that’s suitable for the microbe being tested and then incubate it to see if anything grows.  If no colonies show up…..great!  It’s microbe free.  This is the standard method used to determine the presence of microbes, and it hasn’t really changed in years.

Heavy Metals

Conditions like mercury poisoning are getting more publicity in the media and for this reason heavy metal toxicity is an issue that’s becoming more of a concern.

Heavy metal tests come in three flavors:

  1. Atomic absorbance:  dissolving metal ions in a gas and measuring how much light they absorb.
  2. ICP-OES:  Inductively Coupled Plasma Atomic Emission Spectroscopy.  In english this means electrically charging a substance and then measuring how much radiation it gives off.  Different radiation patterns indicate the presence of different metals.
  3. ICP-MS:  Like ICP-OES, except used with something called a mass spectrometer, which allows you to carefully measure particle size and the electromagnetic energy it gives off which indicates the presence of various heavy metals.

Heavy metals are a nouveau problem right now but testing for them is not.  All these methods are cheap and accurate, with ICP-MS being the most sensitive.  It can measure the presence of metals down to parts per trillion.

Testing for heavy metals is simple.


Ahh, yes……it’s nice to know our acerola powder isn’t actually sawdust, amiright?  

Identity testing is very important because lots of suppliers are good at finding substitute compounds that appear to be the same thing based on subjective characteristics but are in fact totally different.

Certain types of wood can be passed off as pomegranate.  Most herbs have a corresponding weed that looks and feels like the same thing.  Your chelated mineral might actually be an oxide.  The list really goes on and on.

So you must test for identity.

The tests use different acronyms but share a common principle:  different compounds absorb light in different ways, so their absorption spectra acts as a fingerprint that allows you to uniquely distinguish one from another.

These are the light-based tests most commonly use:

  • UV-Vis:  measures how a compound absorbs UV light.
  • FTIR:  measures how a compound absorbs infrared light.
  • NIR:  measures how a compounds absorbs near-infrared light.

With all of these you stick a product in a tube, shine some light on it, and get a graph back with a bunch of peaks and valleys.  The peaks and valleys correspond to the presence of different chemical groups which allows you to determine the purity of the product.

Other identity tests include:

  • TLC:  Thin-layer chromatography.  Mixing a product with a solvent and then measuring how far it travels down a piece of paper.  The length it travels tells you what compound it is.
  • Organoleptic:  Fancy word, crude test.  Organoleptic basically means “let’s just take a look at this shit and see if it looks, smells or tastes like it ought to.”  Simple as that.

The big take home point with these tests is they measure purity but not quantity.  They tell you if something’s there in the form it’s supposed to be in but say nothing about the absolute amount that exists of said compound.

So the next step after identity testing is to measure concentration.

Concentration Testing

Concentration testing has a 900 lb Guerilla that DOMINATES all the other techniques used:  HPLC.

It stands for High Performance Liquid Chromatography.  It’s quick.  It’s accurate.  And the instrument used for the technique can even double as a light saber.  What’s not to love?  The process involves separating molecules based on their polarity and then using some sort of detection method to determine the amount of each ingredient in the mixture.

The big benefit of HPLC is that it separates chemicals very precisely so you can measure how much of something is in a product even if it exists in very small quantities or if there are lots of ingredients in the product being tested

While being able to separate compounds is great, the separation doesn’t give you any data about what the compound is.  So HPLC is finished by pairing its separation technique with a detection technique.

The most common are UV detection or  something called a Photodiode Array.  However, the hip new trend in analytical chemistry is to combine HPLC with a technique called mass spectometry which separates compounds very carefully based on their molecular weight.  The pairing of these two methods is what’s known as LC-MS.

For most final products any of these will work fine, but LC-MS is best if you’re trying to measure something that exists in very small quantities (like a few micrograms or less).

Where Do These Tests Come From?

If you’re a newcomer to the industry you might have the following intelligent thought form between your synaptic cleft:

Where do these tests originate?  How do you know which one should be used for what?

Well checkout the big brain on you!  Glad to see you still have your thinking cap on after 1800 words on a topic you could probably use as a substitute for your Lunesta on your next trans-atlantic flight.

Luckily for us the industry has a few bodies of information that curate various testing methods.  They are:

American Oil Chemists Society – good for all things lipids.

AOAC – THE organization for analytical chemists.

U.S. Pharmacopeial Convention (USP) –  Sets standards for various nutra and pharmaceutical quality control processes.

If you look at a C of A you’ll usually see a reference to some document within these standards to communicate what process was actually used to conduct the test.


Kids, I readily admit that chromatography and ionic gas chambers are not the topics commonly associated with viral journalism.

However, you MUST remember: these details are incredibly important!

Not understanding them is literally the nuts and bolts of how contaminated products make it to store shelves.  So if you’re in the industry, are curious about it, want to get in it, or like to geek out about your supplements…..ignore this at your own peril!

4 thoughts on “How Product Testing Works In The Supplement Industry”

    1. Good question Maurice.

      Sometimes it’s accidental and other times suppliers are duplicitous in substituting one ingredient for the other. If the supplier isn’t high quality it’s not uncommon to use less expensive substitutes or spiking an ingredient with an inferior one……this happens across all product categories. It’s most common in naturally sourced products as opposed to synthetic ones since they’re made in a lab and there’s no seasonality in their availability.


  1. Great article Jonathan,

    I wonder though, how accurate some of the tests are? Especially with metals. I’ve seen these types of reports before and sometimes it’s hard to tell how accurate the findings are when things seem to change from year to year.

    I use supplements with some of my meals or when I juice. But i always aim to go for organic as that goes a long to eliminating many of the major toxins.

    A very interesting read nonetheless though.


    1. Joana,

      Very good point. I recently wrote a corollary article on this topic for the Weston A Price foundation here:

      They can be quite inaccurate, either due to testing conditions, execution, and sometimes the tests themselves have inherently volatile results. It really all depends. In general heavy metal testing is pretty accurate though, even the older methods are pretty accurate down to the parts per billion and the newer methods can detect to the parts per trillion.


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