Why most herbal supplements are not what they claim

In 2015, the New York State Attorney General sent cease-and-desist letters to GNC, Target, Walmart, and Walgreens after DNA testing of herbal supplements found that four out of five products tested contained no DNA from the plant on the label. The testing methodology was later disputed, but the underlying quality problem is real and extensively documented elsewhere.

Under the Dietary Supplement Health and Education Act of 1994, manufacturers do not need to demonstrate safety or effectiveness before selling. The FDA can act after the fact if a supplement is proven harmful, but pre-market review is not required.

What third-party testing finds

ConsumerLab, NSF International, and USP conduct independent testing. Consistent finding: 20-50% of herbal products in any given category fail for wrong species, wrong plant part, wrong dose, contamination, or complete absence of the labeled ingredient. Echinacea products frequently contain the wrong species or plant part. St. John's Wort products show wildly variable hypericin content. Ginkgo products are sometimes adulterated with other flavonoids to simulate a positive test.

On standardization: Manufacturers can add isolated marker compounds to products containing no actual plant and pass standardization tests. Standardization is a quality signal, not a guarantee.

What to look for

Third-party certification is the most reliable signal: NSF International, USP Verified, and ConsumerLab Approved require testing of actual products. Reliable companies: Herb Pharm (tinctures), Gaia Herbs (liquid-filled capsules with traceability), MegaFood. For bulk dried herb: Mountain Rose Herbs and Starwest Botanicals. Ask the supplier: where was the herb grown, how processed, has it been tested for adulterants and heavy metals. A company that cannot answer is not one to buy from. See building a herbal medicine cabinet for a practical starting list.

How to read a certificate of analysis

A certificate of analysis (COA) is the document a testing laboratory produces after analyzing a product. Reputable companies publish these proactively. Key things to look for: identity testing (species confirmed, not just common name); potency testing (marker compound at labeled concentration); heavy metals testing (lead, cadmium, arsenic, mercury at safe levels); microbial testing (absence of pathogens); pesticide residue testing. A COA from an accredited third-party laboratory (ISO/IEC 17025 accreditation) is significantly more reliable than one from the company's own internal lab.

Red flags when evaluating a supplement company

Dramatic health claims (cures, disease reversal); no Latin binomial anywhere on label or website; price that seems too low for the ingredient cost; no information about herb sourcing; a company founded recently with no track record; reluctance to share COAs when asked. Positive signals: third-party certification (NSF, USP, ConsumerLab); published batch-specific COAs; Latin binomial and plant part specified; transparent sourcing; multi-decade track record in the industry.

Frequently asked questions

Are herbal supplements regulated differently than pharmaceuticals? Yes, significantly. Pharmaceuticals require pre-market approval demonstrating safety and efficacy. Dietary supplements do not. The regulatory burden is lower, which is why quality varies so much between products.

Is expensive always better? Not always. But price below a certain threshold is a meaningful warning sign. If a product price does not cover the cost of quality raw material plus reasonable testing and manufacturing, something is missing. See also: building a herbal medicine cabinet for a practical approach to spending wisely on the right things.