What Third-Party Testing Actually Means for Supplements
An educational overview of Certificates of Analysis, lot-specific testing, identity and potency verification, and how to evaluate supplement transparency in practice.
The Problem with "Third-Party Tested"
If you've shopped for supplements, you've seen the phrase "third-party tested" on packaging, websites, and advertising. It sounds reassuring. It's meant to. But on its own, it tells you very little.
That's because "third-party tested" does not, by itself, tell you what was tested, how often testing occurs, or what standards were applied. The phrase itself does not communicate a uniform testing scope, frequency, or reporting standard. A brand can send a single sample to an outside lab once, receive a passing result, and call every bottle it ever produces "third-party tested." A different brand can test every production lot across multiple categories — identity, potency, purity, heavy metals, microbial safety — and use the exact same phrase.
Both claims may sound similar, but they can reflect very different levels of quality assurance.
This article is designed to help you understand what meaningful supplement testing looks like, what a Certificate of Analysis actually contains, and how to evaluate transparency claims from any brand — including ours.
What a Certificate of Analysis Is
A Certificate of Analysis — usually called a COA — is a document produced by a laboratory that reports the results of testing performed on a specific batch of product or raw material. It typically includes the product or material name, a batch or lot number, the date of testing, the name of the laboratory, and a table of test results showing what was measured, what the specification was, and whether the result met the specification.
COAs exist at multiple levels in the supplement supply chain. A raw material COA documents testing on an individual ingredient before it goes into a formula. A finished product COA documents testing on the completed supplement after manufacturing. Both serve different purposes, and serious quality programs use both.
The important thing to understand is that a COA is tied to a specific lot. It documents what was tested in that particular production run. It does not automatically apply to other lots, earlier batches, or future production. That distinction matters more than most consumers realize.
What Labs Actually Test For
When a supplement undergoes meaningful third-party testing, the laboratory is typically evaluating several distinct categories. Each one answers a different question about the product.
Identity: Is this ingredient what it claims to be?
Identity testing confirms that the raw material or finished product contains the ingredient listed on the label — not a substitute, adulterant, or mislabeled material. This might sound like a baseline expectation, but ingredient substitution is a documented problem in the supplement supply chain. Botanical extracts, for example, can be diluted with cheaper plant material that looks similar but doesn't contain the target compounds.
Common identity testing methods include infrared spectroscopy (FTIR), which compares a sample's molecular fingerprint against a reference standard, and high-performance liquid chromatography (HPLC), which separates and identifies specific compounds within a sample. For a raw material like ox bile extract, identity testing confirms the presence of expected bile acid compounds. For a botanical like artichoke extract, it confirms the presence of the target compound — in that case, cynarin.
Potency: Does it contain the amount stated on the label?
Potency testing — sometimes called assay testing — measures the actual concentration of the active compound and compares it against the label claim. If a supplement label says "500 mg ox bile extract (≥45% bile acids)," potency testing verifies that the bile acid content actually meets or exceeds that 45% threshold.
This is where the analytical method matters. HPLC is commonly used for potency verification because it can quantify specific compounds with precision. When you see "Method: HPLC" on a COA next to a potency result, it means the lab used chromatographic separation to measure the actual concentration — not an estimate or a calculation based on the raw material input.
The gap between what goes into the blender and what comes out in the finished capsule is where potency problems hide. Ingredients can degrade during manufacturing, mixing may be uneven, or the raw material itself may have been under-spec from the supplier. Potency testing on the finished product catches these issues. Testing only the raw material inputs does not.
Purity and Contaminant Screening: What else is in there?
Purity testing looks for things that should not be present in the product. The most common categories are heavy metals testing and microbial testing, though depending on the product, labs may also screen for pesticide residues, solvent residues, or other environmental contaminants.
Heavy metals. Supplements can pick up heavy metal contamination from soil, water, processing equipment, or raw material sourcing. The metals most commonly screened are lead, mercury, arsenic, and cadmium — all of which have established safety thresholds. Testing is typically performed using ICP-MS (inductively coupled plasma mass spectrometry), which can detect metals at parts-per-billion levels. A COA will show the result for each metal alongside the specification limit (for example, "Lead: <1 ppm | Result: <0.07 ppm").
Microbial safety. Microbial testing screens for bacteria, yeast, mold, and specific pathogens like Salmonella, E. coli, and Staphylococcus aureus. These tests use USP-validated methods (the USP is the United States Pharmacopeia, which sets testing standards for pharmaceuticals and dietary supplements). Results are reported as colony-forming units per gram (cfu/g) for total aerobic count and yeast/mold count, and as "Negative" or "Absence" for specific pathogens.
Clean microbial results generally reflect strong manufacturing and handling controls — facility sanitation, environmental monitoring, ingredient handling, and moisture control throughout the process.
Dissolution and Delivery Verification
For supplements that use specialized delivery systems — such as delayed-release capsules — there's an additional testing category that standard COAs don't always cover: dissolution testing. This verifies that the capsule actually behaves as intended — resisting dissolution in acidic conditions (simulating stomach acid) and releasing its contents in a higher-pH environment (simulating the small intestine).
This type of testing is particularly important for formulations where the delivery mechanism is a core part of how the product is designed to work. If a supplement claims to be "delayed-release" but has never been tested to confirm that the capsules actually resist premature dissolution, the claim is marketing language, not a verified performance characteristic.
Why Lot-Specific Testing Matters
One of the most important questions you can ask about a brand's testing program is: do they test every production lot, or did they test once?
Manufacturing is not perfectly consistent. Raw material quality varies between suppliers and between shipments from the same supplier. Equipment conditions shift. Environmental factors change. A result from Lot A does not guarantee the same result for Lot B — especially if Lot B was produced weeks or months later with a different batch of raw materials.
Lot-specific testing means that each production run gets its own COA, with results tied to that specific batch. If you can look up a COA by your bottle's lot number and see test results specific to that production run, that's a meaningful quality indicator. If a brand publishes a single COA with no lot number — or a COA from a "representative batch" — it's worth asking what was tested and when.
This is also why the lot number on your bottle matters. It's not just a manufacturing code — it's the traceability link between your specific product and the testing documentation that verifies it.
What a COA Does Not Prove
Being transparent about limitations is part of being transparent about quality. A COA is a powerful quality document, but it has boundaries.
A COA does not prove that a supplement will work for you. It confirms what's in the product, how much of each ingredient is present, and that it meets safety specifications. It says nothing about whether those ingredients will produce the outcome you're hoping for. Efficacy depends on the formulation logic, the dosing, the delivery mechanism, and your individual biology — none of which a lab test can evaluate.
A COA does not prove that the manufacturing facility meets quality standards. That's the role of cGMP (current Good Manufacturing Practice) compliance — a separate set of FDA-mandated requirements covering facility design, equipment calibration, personnel training, batch records, and quality control procedures. A well-run testing program and cGMP-compliant manufacturing go together, but they're not the same thing.
A COA does not guarantee long-term stability. Test results reflect the product at the time of testing. Whether those results hold throughout the product's shelf life depends on formulation stability, packaging, and storage conditions. That's why reputable manufacturers conduct stability testing and assign expiration dates based on data, not estimates.
And a COA does not replace professional medical guidance. No amount of quality documentation changes the fact that supplement decisions should be made in consultation with your healthcare provider, especially if you have underlying health conditions or are taking medications.
How to Evaluate a Brand's Transparency Claims
If you want to assess how seriously a supplement brand takes testing and transparency, here are the questions worth asking — whether you're evaluating Medisyn Labs or anyone else.
Can you see actual COAs, or just claims about testing? A brand that says "third-party tested" but doesn't publish or provide COAs on request is asking you to take their word for it. Look for brands that make documentation available — either publicly or by request with a lot number.
Are the COAs lot-specific? A COA should reference a specific lot or batch number that you can match to your product. A generic COA with no lot number, or one that references a "master batch" or "representative sample," provides less assurance.
What testing categories are covered? A meaningful COA covers identity, potency, heavy metals, and microbial safety at minimum. If a brand's COA only shows one or two of these categories, the testing program may be incomplete.
Who performed the testing? "Third-party" means the testing was done by a laboratory independent of the manufacturer. The COA should name the lab or be issued on the lab's letterhead. In-house testing by the manufacturer can be part of a quality program, but it isn't independent verification.
Does the label disclose actual ingredient amounts? Testing is only meaningful if you can verify what's being tested against what's claimed. Brands that use "proprietary blends" — listing ingredients without individual amounts — make it impossible for you to compare COA potency results against label claims, because the label doesn't tell you what the target amount was for each ingredient.
Is the brand willing to explain their testing? Transparency isn't just about posting documents. It's about being willing to answer questions — about methodology, about suppliers, about what happens when a result doesn't meet spec. A brand that's confident in its quality program isn't defensive about discussing it.
How This Works at Medisyn Labs
We built our quality program around the principle that documentation should be available, not just assertions. Here's what that looks like in practice.
Every production lot of Gallavance Original and Gallavance Plant-Based undergoes testing that covers identity verification, potency/assay, heavy metals screening (lead, mercury, arsenic, cadmium via ICP-MS), and microbial analysis (total aerobic count, yeast and mold, and pathogen screening via USP methods). Raw material COAs from our ingredient suppliers are verified and retained as part of the batch record.
We publish lot-specific COAs in our COA Library, accessible by lot number, by QR code on your bottle, or by request at any time — including before purchase. We also disclose every ingredient and every amount on our label. No proprietary blends. No hidden quantities. That means when you look at a Gallavance COA, you can compare every potency result against the exact amount printed on the Supplement Facts panel.
Our products are manufactured in a U.S.-based, FDA-registered, cGMP-compliant facility. Testing is performed by qualified laboratories independent of the manufacturing facility.
We do not view this as a premium extra. We view it as part of the baseline for responsible supplement manufacturing. And we believe you should expect the same standard from every supplement you take.
The Takeaway
"Third-party tested" is a starting point, not a finish line. The real questions are: tested for what, how often, by whom, and can you see the results? When you know what to look for, you can move past marketing language and evaluate supplement quality on evidence — which is how it should work.
If you'd like to see what meaningful testing documentation looks like in practice, visit our COA Library.
† These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Gallavance™ is a product of Medisyn Labs, LLC. "The Supplement That Proves Itself™" is a trademark of Medisyn Labs, LLC.