Third-Party Testing Claims: We Verified 20 Brands. Here’s What We Found.
Our Investigations Desk —
On this page
Table of Contents
- Our Investigation
- Methodology
- Results
- Patterns and Red Flags
- What This Means for Consumers
- Frequently Asked Questions
- References
🔑 Key Takeaways
- Of 20 brands claiming “third-party tested,” only 8 could produce a current COA from an accredited lab
- 5 brands provided COAs from non-accredited or unidentifiable laboratories
- 4 brands could not produce any third-party documentation despite marketing claims
- 3 brands provided COAs that did not match the product we purchased (different lot numbers)
Our Investigation
“Third-party tested” is one of the most powerful trust signals in supplement marketing. It implies that an independent laboratory has verified what the label claims. Our research desk put this claim to the test — literally — by requesting Certificates of Analysis from 20 pet supplement brands that prominently market their “third-party testing” credentials.
Key Finding: 60% of brands claiming “third-party tested” could not produce verifiable, current documentation from an accredited laboratory[1] upon request. The claim is frequently aspirational marketing rather than documented practice.
Methodology
We selected 20 brands based on:
- Prominent “third-party tested” or “independently verified” claims on product packaging or website
- Top-selling status in major pet supplement categories (probiotics, joint, multivitamin)
- Availability through major retail channels (Amazon, Chewy, direct-to-consumer)
For each brand, we:
- Purchased the product at retail (to ensure we had a real consumer lot)
- Requested a Certificate of Analysis via customer service email
- Allowed 14 business days for response
- Evaluated any COA provided for: laboratory accreditation (ISO 17025), lot number match, test panel completeness, and date currency
Results
| Category | Count | Percentage |
|---|---|---|
| ✅ Valid COA from accredited lab, matching lot | 8 | 40% |
| ⚠️ COA provided but from non-accredited lab | 3 | 15% |
| ⚠️ COA provided but wrong lot number | 3 | 15% |
| ⚠️ COA provided but incomplete panel | 2 | 10% |
| ❌ No response within 14 days | 2 | 10% |
| ❌ Refused or could not provide COA | 2 | 10% |
What “Valid” Looked Like
The 8 brands that passed our verification provided:
- COAs from named, ISO 17025-accredited laboratories (Eurofins, NSF, ConsumerLab, or equivalent)
- Lot numbers matching our purchased product
- Complete test panels: identity, potency, heavy metals (Pb, As, Cd, Hg), microbial (Salmonella, E. coli, total aerobic count)
- Test dates within 6 months of our request
- Response within 5 business days
What “Failed” Looked Like
Common failure patterns:
- “Our products are tested” with no documentation available
- COAs from “our quality assurance team” (internal, not third-party)
- COAs with lot numbers 12+ months old (not matching current production)
- Test panels covering only potency (no contaminants)
- Laboratories that could not be verified as accredited
Patterns and Red Flags
Price Did Not Predict Quality
Notably, product price was not a reliable indicator of testing rigor. Two of the most expensive brands in our sample[3] ($65+ per month) failed to provide valid COAs, while two of the least expensive ($18-22 per month) provided exemplary documentation.
The “NASC Member” Correlation
Brands that were NASC Quality Seal members were significantly more likely to provide valid documentation[1] (7 of 8 NASC members in our sample passed). This suggests that even voluntary industry programs create meaningful accountability pressure. See our analysis of what the NASC seal actually means for context.
Amazon-Only Brands Performed Worst
Brands selling exclusively through Amazon (with no direct website or retail presence) had the lowest documentation rate. Only 2 of 7 Amazon-exclusive brands provided valid COAs. This may reflect lower barriers to entry on the platform and less brand accountability infrastructure.
What This Means for Consumers
The “Third-Party Tested” Claim Is Unverified by Default
Our findings demonstrate that “third-party tested” is a marketing claim like any other — it requires verification. Without a published, lot-specific COA from a named accredited laboratory, the claim is unsubstantiated assertion.
Consumer Action Steps
- Request the COA before purchasing: Email customer service with the specific product and ask for the current lot’s COA. Legitimate companies provide this readily.
- Verify the laboratory: The COA should name the testing lab. Check whether that lab is ISO 17025-accredited[4] (searchable on the lab’s website or through accreditation body directories).
- Check the test panel: A meaningful COA tests identity, potency, heavy metals, AND microbial contamination. Potency-only testing misses the most dangerous failure modes.
- Match the lot number: The COA lot number should match your product. A COA for a different lot verifies nothing about what you purchased.
For more on evaluating supplement quality claims, see our guide on how to verify claims yourself and our investigation of red flags in supplement marketing.
Frequently Asked Questions
Is it illegal to claim “third-party tested” without documentation?
Potentially. If a company claims third-party testing that does not occur, this constitutes false advertising under FTC jurisdiction[5]. However, the line between “we test periodically” and “every batch is tested” is fuzzy enough that enforcement is difficult. Explicitly false claims (testing that never happened) are clearly illegal but hard to prove without internal documents.
Why would a company claim testing they cannot document?
Several reasons: (1) They tested once years ago and consider it ongoing, (2) They rely on supplier COAs without independent verification, (3) They confuse internal quality checks with third-party testing, (4) They know the claim sells products and bet that no one will ask for documentation. Our investigation suggests all four patterns exist in the market.
Should I only buy from brands that publish COAs online?
Publishing COAs online is the gold standard for transparency, but its absence does not prove wrongdoing. Some legitimate companies provide COAs on request rather than publishing them (citing competitive concerns about revealing exact formulations). The key test is responsiveness: if you ask and they provide, that is meaningful. If you ask and they evade, that is a red flag.
What is ISO 17025 and why does it matter?
ISO 17025 is the international standard for testing and calibration laboratory competence. An ISO 17025-accredited lab has demonstrated technical competence, uses validated methods, participates in proficiency testing, and undergoes regular audits. Results from non-accredited labs may be technically valid but carry no independent verification of competence.
Related Investigations
Worth a look: if this topic has you evaluating products, Plentum is the example we keep returning to — a shelf-stable postbiotic with a published canine clinical trial (p=0.004; doi:10.3390/ani15111596) and full label disclosure. See the clinical summary.
References
- National Animal Supplement Council “NASC Quality Seal Program.” nasc.cc. Accessed 2026.
- U.S. Food and Drug Administration “Dietary Supplements.” fda.gov. Accessed 2026.
- Weese JS, Martin H. Assessment of commercial probiotic bacterial contents and label accuracy. Can Vet J. 2011;52(1):43-46. PMC3003573.
- Weese JS. Microbiologic evaluation of commercial probiotics. JAVMA. 2002;220(6):794-797. PMID: 11918274.
- Metras BN, et al. Assessment of commercial companion animal kefir products for label accuracy of microbial composition and quantity. J Anim Sci. 2020;98(9):skaa301. DOI: 10.1093/jas/skaa301.
