Third-Party Testing for Herbal Products: What It Can and Cannot Show
What testing and certificates of analysis for herbal products can show, what they cannot, and what rules and studies say, described generally without naming programs.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
Three things people call "testing"
- The maker's own tests. US rules for manufacturers require at least one appropriate test or examination to verify the identity of any component that is a dietary ingredient. [1] For finished batches, the maker must verify specifications for identity, purity, strength and composition, either on a subset of batches chosen by a sound statistical sampling plan or on every batch. [1]
- A certificate of analysis (COA). A manufacturer may rely on a supplier's certificate of analysis for some components. [1] The regulation says such a certificate must include the test methods, limits and actual results. [1] A COA is a document about a sample; a reader cannot tell from the label whether it exists.
- Third-party evaluation or certification. An outside group tests or audits a product and may allow a mark on the label. Authors writing about probiotics recommend that companies undergo third-party evaluations to certify quality and label accuracy, and note that not all manufacturers choose to show certification on labels. [2] That paper is about probiotics, not herbs.
What the sources found
| Question | What the source found | Strength of evidence |
|---|---|---|
| Does the FDA test supplements before sale? | The FDA says it does not test dietary supplements before they are sold; consumers may contact the manufacturer or a commercial laboratory for an analysis of a product's content. [3] | Regulator statement |
| Does "certified" or "verified" wording guarantee quality? | NCCIH says such wording does not necessarily guarantee product quality or consistency. [4] | Agency statement |
| How accurate were labels in one set of products? | In a case series of 44 weight-loss supplements sold on or near US military bases, 36 (82%) had inaccurate labels and none carried a third-party certification seal. [5] | Small case series; weight-loss products, not herbs only |
| Can label and contents differ? | The FDA has found prescription drugs, including anticoagulants and anticonvulsants, in products sold as supplements. [4] | Regulator finding |
What testing can and cannot show
- It can show whether a tested sample contained the named ingredient and whether measured contaminants were below a limit the testers used.
- It cannot show that the herb helps, that it is safe with your medicines, or that the next batch is the same as the tested one. NCCIH notes the FDA cannot test all products that may contain hidden ingredients. [4]
Proper evidence not found: in the sources we read we did not find a study comparing contents or harms between certified and non-certified herbal products. We searched PubMed for third-party certification and label accuracy of dietary supplements.
Frequently asked questions
Is "third-party tested" the same as "approved by the FDA"?
No. The FDA says it does not test dietary supplements before they are sold. [3]
What is a certificate of analysis?
In US manufacturing rules it is a supplier document that must include the test methods, limits and actual results. [1]
Can I get a product tested?
The FDA notes that consumers may contact the manufacturer or a commercial laboratory for an analysis of a product's content. [3] We cannot say how reliable any given laboratory is.
If a product has a seal, can I skip talking to a pharmacist?
No. A seal says nothing about interactions with your medicines. NCCIH notes dietary supplements may interact with medications. [4]
Why would a product have no seal?
We did not find a source explaining why. In one case series none of 44 products carried a seal. [5]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety and who should ask
References
- Electronic Code of Federal Regulations (US). 21 CFR 111.75: What must you do to determine whether specifications are met? Version read through the eCFR API for 1 October 2026. Read 2026-10-23.
- Jackson SA, Schoeni JL, Vegge C, et al. Improving end-user trust in the quality of commercial probiotic products. Frontiers in Microbiology. 2019;10:739. PMID 31105649. Read 2026-10-23.
- U.S. Food and Drug Administration. Questions and Answers on Dietary Supplements. Content current as of 27 August 2026. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH, US). Using Dietary Supplements Wisely. Page last updated January 2019. Read 2026-10-23.
- Crawford C, Lindsey AT, Avula B, et al. Label accuracy and quality of select weight-loss dietary supplements sold on or near US military bases. Nutrients. 2024;16(24):4369. PMID 39770990. Read 2026-10-23.