If you walk through the supplement aisle today, you will find it nearly impossible to buy a product that does not have the words “third-party tested” somewhere on the label. The phrase is now so universal it has stopped carrying information. It is wallpaper.
And yet the FDA estimates that 50–70% of dietary supplements sold in the U.S. contain measurably different amounts of active ingredient than the label claims — sometimes by orders of magnitude [1]. Both things are true at once: testing claims are everywhere, and the products on the shelf are wildly inconsistent.
Here’s how to read what the label is actually telling you.
1. “Tested” vs. “certified” vs. “verified”
“Third-party tested” is the weakest of the three phrases — it implies somebody, at some point, ran some test. It does not imply that every batch is tested, that the tests check for the things you care about, or that the results were within specification.
“Certified” by a named program (USP Verified, NSF Certified for Sport, ConsumerLab approved) is a stronger claim, because the certifying body has rules about what tests must be run, how often, and what the lab’s accreditation status must be.
2. Ask for the COA
A Certificate of Analysis (COA) is the document the laboratory produces for each batch. It lists the analytes tested, the method used, the result, and whether each result is within specification. A brand that takes testing seriously will publish the COA for the batch you bought, on the product page, with the lot number you can match against your bottle.
“If they can’t show you the certificate for the lot you’re holding, the word ‘tested’ on the bottle is doing no work.” — Dr. Pieter Cohen, Cambridge Health Alliance
3. Find out which lab
The gold standard is ISO/IEC 17025 accreditation — an international standard for the competence of testing labs. Reputable supplement testing labs (Eurofins, NSF, Alkemist Labs, ChromaDex) will be 17025-accredited for the specific analytical methods they’re running.
4. Check what they tested for
A botanical supplement should be tested for: active-compound potency (HPLC), heavy metals (ICP-MS for lead, arsenic, cadmium, mercury), microbial contamination, and — critically — species identity. The 2013 New York Attorney General investigation into herbal supplements found that 79% of products from major retailers contained no detectable DNA from the herb on the label [2]. Identity testing is not optional.
5. What we do at PrimaGround
Every batch we produce is sent to two ISO 17025–accredited labs (Eurofins and Alkemist Labs) before it ships. We test for HPLC potency, heavy metals, microbial load, and — for our botanicals — DNA species verification. The COA for every batch is published on the product page, indexed by lot number, free to download. If a batch fails specification, it is destroyed. We have destroyed three batches.
None of this is special. It is what the words on the label are supposed to mean.
[1] Cohen PA. JAMA, 2014. [2] New York State Office of the Attorney General, 2015 herbal supplement investigation.