Walk through any pharmacy supplement aisle and “natural” is everywhere. It’s on ginseng capsules, protein powders, herbal tinctures, prenatal gummies, beauty collagen drinks. The word appears on roughly two-thirds of supplement products on US shelves — often in forest-green type next to a tasteful leaf icon. And according to the FDA, it has no legal definition when applied to dietary supplements.
That’s not a technicality. It’s a gap that costs consumers real money and, in some cases, real harm.
The FDA Has No Legal Definition of “Natural” for Dietary Supplements
For conventional packaged foods, the FDA maintains an informal policy: “natural” means the product doesn’t contain artificial or synthetic ingredients, including added colors. But they’ve never codified that into enforceable law — and it doesn’t extend to dietary supplements at all. Under the Dietary Supplement Health and Education Act of 1994 (DSHEA), supplement manufacturers are not required to get FDA approval before selling a product. They’re legally responsible for ensuring safety, but the burden of proving a product unsafe falls on the FDA after the fact.
That means a company can print “all-natural formula” on a bottle of turmeric capsules without meeting any specific legal threshold for what that claim means. No one verifies it before the product ships to a retailer. The FTC has guidelines against deceptive marketing — and has taken enforcement action in egregious cases — but there’s no bright-line definition that supplement manufacturers must meet to use the word “natural.”
The FDA estimates there are now more than 80,000 dietary supplement products on the US market. The vast majority have never been independently tested.
”Natural” Ingredients Can Still Be Contaminated — Or Dangerous
Here’s the part that surprises people most: something can be 100% naturally derived and still pose genuine health risks.
Arsenic is natural. Lead is natural. Both occur in soil, which means they can concentrate in the roots, stems, and leaves of plants. Herbs marketed as “natural” or “organic” — ginseng, turmeric, ashwagandha, spirulina — have repeatedly turned up in independent testing with detectable levels of heavy metals. A 2023 review of herbal supplement testing data found lead contamination at levels exceeding California Proposition 65 thresholds in approximately 30% of sampled products from certain botanical categories.
Pesticide residues are another issue. Much of the world’s supplement raw material supply originates in agricultural regions of Asia and South America, where some pesticides not approved for US use are still applied to crops. “Natural” on the finished product label tells you nothing about what the raw material went through before it was processed, encapsulated, and shipped.
And then there are naturally occurring compounds that are simply toxic at the wrong dose or in the wrong person. Comfrey contains pyrrolizidine alkaloids, which can cause serious liver damage with prolonged use. Aristolochic acid — found in some traditional herbal preparations — is classified as a Group 1 human carcinogen by the IARC. Kava has been associated with hepatotoxicity at higher doses, particularly in people with certain genetic variants affecting liver enzyme activity. None of that changes because the ingredient came from a plant.
But the “natural” label doesn’t mention any of this.
What Manufacturers Are (and Aren’t) Required to Disclose
Under DSHEA, manufacturers must notify the FDA at least 75 days before marketing a new dietary ingredient — but only for ingredients introduced after October 15, 1994. Anything on the market before that date was grandfathered in with no pre-market safety review required. Supplement labels must include a Supplement Facts panel, and companies are required to follow FDA Good Manufacturing Practices (GMPs) under 21 CFR Part 111, which govern facility hygiene, raw material identity testing, and record-keeping.
But GMP compliance doesn’t require finished-product potency testing. It doesn’t require third-party verification. And it doesn’t require evidence that the product actually does what the front label implies.
In 2015, a study published in JAMA Internal Medicine identified 776 dietary supplements containing unapproved pharmaceutical ingredients — including synthetic stimulants, anabolic steroids, and phosphodiesterase-5 inhibitors — hidden inside products marketed as “natural” weight loss, sexual enhancement, or muscle-building aids. Many of those bottles featured the word “natural” prominently on the label.
The FDA has issued warning letters and import alerts in response to cases like these. But post-market enforcement is reactive by design. By the time a product is flagged, it may have been sold to hundreds of thousands of consumers.
The Third-Party Certifications That Actually Mean Something
If “natural” tells you almost nothing, what should you actually look for?
Third-party certification programs are the closest thing US consumers have to verified quality claims on supplement labels. The most established include:
USP Verified: The United States Pharmacopeia runs a voluntary certification program that tests for label accuracy, contaminant levels, and bioavailability — whether the product will actually dissolve and be absorbed in the body. As of 2024, fewer than 1,000 supplement products carry USP Verified status out of tens of thousands on the market. That low number reflects both the cost of certification and the fact that many products simply can’t pass.
NSF Certified for Sport: NSF International tests for more than 270 substances prohibited in competitive sport, in addition to verifying label claims and screening for contaminants. If you’re an athlete subject to anti-doping rules — or just want the added scrutiny — this seal matters.
Informed Sport / Informed Protein: A batch-level testing program (meaning each production lot is tested, not just a one-time brand certification) with strong adoption across US supplement brands.
ConsumerLab.com Approved Quality: ConsumerLab independently purchases and tests supplements and publishes results publicly. Their test failures are as informative as their passes. It’s worth checking their database before committing to a new product.
None of these programs are required by law. They cost manufacturers real money to pursue and maintain. That’s exactly why their presence on a label signals genuine quality commitment in a way that printing “natural” in green font simply doesn’t.
How to Actually Read a Supplement Label
I hear from a lot of people — listeners, readers, folks in my DMs — who spend five or ten minutes choosing a supplement based on the front panel (“natural,” “pure,” “doctor-formulated,” “clinically studied”) and about 30 seconds on the Supplement Facts. It should be exactly the opposite.
A few things worth checking every time you flip to the back:
Serving size versus single-unit amounts. A supplement might advertise “500 mg of ashwagandha per serving” on the front in large type, but list a serving size of 3 capsules. That’s roughly 167 mg per capsule — still meaningful, but a very different picture than the front label implies. Know what you’re actually getting per dose.
“Proprietary blend” is a transparency red flag. When several ingredients are grouped under a blend with only a total combined weight disclosed, you can’t know whether each ingredient is present at a clinically relevant dose. It’s a legal mechanism for hiding underdosed or low-cost filler ingredients behind a high-value ingredient name.
Third-party certification logos. These usually appear on the back panel or bottom of the front label. If you don’t see one, the product hasn’t been externally verified — regardless of what the front marketing says.
The manufacturer’s FDA compliance history. The FDA maintains a publicly searchable database of warning letters and import alerts. If a company has received enforcement action, it’s there. Takes about 90 seconds to check — and the results can be startling.
The required disclaimer. Any supplement making a structure/function claim (“supports immune health,” “promotes relaxation”) is required by law to display: “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.” If you see that disclaimer alongside a very specific health claim, treat it as exactly the hedge it is.
The Word You Should Actually Be Looking For
According to testing data from Qalitex Laboratories, a notable share of supplement products sampled in routine third-party testing show label accuracy discrepancies — either stated ingredient levels that don’t match what’s in the bottle, or contaminant levels above acceptable thresholds. The products most consistently free of those issues are the ones carrying recognized third-party certifications — not the ones with the best marketing vocabulary.
“Natural” has become a comfort word. It signals purity, simplicity, and wholesome origins. Those are real values — they’re just not what the word delivers on a supplement label, where it means exactly as much as the company that printed it wants it to mean.
The next time a supplement catches your eye because of the green font and the leaf motif, flip it over. Find the Supplement Facts panel. Look for a third-party certification seal. Check the disclaimer. And if you can’t find a single external verification — from USP, NSF, ConsumerLab, Informed Sport, or anyone else — ask yourself what the manufacturer is choosing not to verify.
That question is worth more than any marketing claim on the front.
Written by Nour Abochama, Host & Quality Control Expert, Nourify & Beautify. Learn more about our team
Have questions about product safety? Talk to our experts. Contact us
Related from our network
- What Third-Party Supplement Testing Actually Covers — From a Lab That Does It — Qalitex Laboratories walks through what happens when a supplement enters an ISO 17025-accredited facility, from identity testing to heavy metal screening.
- How to Evaluate a Raw Material COA Before It Reaches Your Formula — Ayah Labs explains what a Certificate of Analysis should include — and how to spot the gaps that leave finished products at risk.
