Verified · Updated June 2026
Trust built on transparency
Every batch is verified by two ISO-accredited labs before it ships.
Summit Nutritional Laboratories tests for heavy metals and microbial contamination.
Harken Research Laboratories confirms every active ingredient is present at the dose on the label.
The results are published below.
Two labs. One standard.
We split verification across two specialized labs because no single facility excels at everything. This costs more. It also means no shortcuts — and no lab grading its own homework.
Safety testing
Summit Nutritional Laboratories
Location
Spanish Fork, Utah
Accreditation
ISO/IEC 17025:2017 · PJLA #75696
Scope
Heavy metals · Microbiology
Methods
ICP-MS · AOAC · PCR
Potency verification
Harken Research
Location
Pasadena, California
Accreditation
ISO/IEC 17025 · ANAB Cert. AT-3228
Scope
Active ingredients · Minerals
Methods
HPLC · LC-MS/MS · ICP-MS
What we test for
Most supplement brands say "third-party tested." We'll show you exactly what that means.
Potency
Every active ingredient in every batch is measured by HPLC and LC-MS/MS against the dose printed on the label. Meaning what's on the bottle is what's in the capsule, every time. Industry audits routinely find supplements under-dosed by 30% or more. We publish the actual measured milligrams, batch by batch.
Heavy metals
Arsenic, cadmium, lead, and mercury — screened on every batch by ICP-MS to USP <2232>, the same standard used by pharmaceutical manufacturers. All released batches have tested at a fraction of the allowable limit on every analyte. Not "within spec." Well inside it.
Microbial contamination
Total plate count, total coliform, E. coli, Salmonella, Staphylococcus aureus, and yeasts & molds — six screens per batch using AOAC and PCR methods. A clean facility should produce a clean product. We confirm it instead of assuming it.
Identity
Every raw material is verified. The molecule on the certificate is the molecule in the bottle.
Find your batch
Enter the LOT number printed on the bottom of your bottle, or browse by product below.
Couldn't find that LOT — email info@mareksupplements.com with your LOT number and product, we'll dig out the report.
Questions, answered
What is a Certificate of Analysis?
A lab-issued document confirming that a specific batch has been tested and meets defined safety and quality specifications. It lists the analytes tested, the limits applied, the measured results, and the lab's accreditation. Every batch we ship has one, and they're all on this page.
How do I read a Certificate of Analysis?
Each COA reports the tested analytes, the methods used, the measured results, and pass/fail status against the specification. The header gives you the product and LOT number; the body lists each active ingredient, contaminant screen, and microbiological test, with the lab's name and accreditation on every report. For a worked example using a real Marek batch — section by section — see our line-by-line COA walkthrough.
How often do you test?
Every batch. Not random samples, not annual checks — every production run is held until the lab results show a passing report. The LOT number on your bottle corresponds to a single, specifically tested batch.
Why two labs instead of one?
Safety testing and potency testing require different instrumentation, methods, and accreditation scopes. Splitting the work between specialists means each test is run by a lab whose accreditation specifically covers that test. It costs more. It also means no one lab is grading its own homework.
Are raw materials tested, or only the finished product?
Both. Raw materials are identity-tested before they enter the formula, and the finished, encapsulated product is tested again before release. Heavy metals can concentrate during processing — finished-product testing is the only way to know what's actually in the capsule.
Where do I find my LOT number?
Printed on the bottom of your bottle in gold ink — typically eight digits. Match it to a product above to view that batch's COA.
What if my LOT isn't listed?
Email info@mareksupplements.com with the LOT and product name. We keep archival records of past batches.
Why don't more supplement brands publish COAs?
Some don't test. Some test but don't publish because they don't like what they find. Some publish a single sample COA from years ago. Publishing every lot creates accountability. Accountability's cool.
“Every batch of Marek Health supplements undergoes dual-lab verification. We publish results for every lot because… transparency isn’t a feature — it’s the standard.”