Can a supplement be sold as "natural" if it contains synthetic ingredients?
There's no legal definition of "natural" — but that hasn't stopped the FTC from calling the claim illegal anyway.
Legally, no — even though neither the FDA nor the FTC has ever written a formal definition of the word "natural." That gap sounds like it should be a loophole, but the FTC has closed it in practice: in a string of enforcement actions, it has ruled that advertising a product as "all natural" or "100% natural" while it actually contains synthetic ingredients is a deceptive practice under Section 5 of the FTC Act, regardless of the missing formal definition.
The precedent — In re California Naturel
The clearest example is the FTC's case against California Naturel, a sunscreen brand that advertised its product as containing "only the purest, most luxurious and effective ingredients found in nature," despite the formula being 8% dimethicone, a synthetic ingredient. The company argued its ingredient list and a website disclaimer covered it. The FTC disagreed on both points: the synthetic ingredient was buried among more than 30 listed ingredients with nothing flagging it as synthetic, and the disclaimer sat below the "Add to Cart" button where it wasn't prominent. The Commission's final order barred the company from making "all natural" claims at all.
The FTC brought similar actions the same year against several personal-care brands for the same pattern — "natural" or "100% natural" claims on products containing ingredients like dimethicone, phenoxyethanol, and polyethylene — and more recent private class actions have targeted "all natural" claims on supplements and drink mixes containing synthetic ingredients like maltodextrin.
Why "no legal definition" doesn't mean "no rule"
| What's true | What it doesn't mean |
|---|---|
| No FDA or FTC regulation formally defines "natural" | Companies can call anything "natural" without consequence |
| The FTC hasn't set a bright-line percentage or ingredient list | A synthetic-heavy product is safe from enforcement |
| A company can technically list every ingredient honestly | A buried, honest ingredient list excuses a false headline claim |
The FTC's standard is simpler than a formal definition: does the claim mislead a reasonable consumer? An "all natural" label next to a product that's meaningfully synthetic fails that test regardless of what's technically disclosed elsewhere on the package.
What to check before trusting a "natural" claim
- Read the full ingredient list, not just the front-of-package claim — look for common synthetic additives (preservatives, stabilizers, artificial flavors or colors)
- Be skeptical of "all natural" or "100% natural" specifically, since those are the exact phrases the FTC has repeatedly found deceptive when synthetic ingredients are present
- A qualified claim ("made with natural flavors") is a narrower, more defensible statement than an unqualified "100% natural" — the broader the claim, the more it has to be true
What to do if you bought a falsely "natural" supplement
- Compare the marketing claim against the actual ingredient list to confirm the mismatch.
- Screenshot both the marketing claim and the ingredient panel before either can be edited.
- File a complaint with the FTC at ReportFraud.ftc.gov, since this is squarely the kind of claim the agency has pursued before.
- Check whether your state has its own false-advertising statute — many "natural" claim disputes are resolved through state consumer-protection class actions rather than federal cases alone.
Is there an official legal definition of "natural" for supplements? No. Neither the FDA nor the FTC has adopted a formal regulatory definition of 'natural.' Despite that gap, both agencies treat an unqualified 'all natural' or '100% natural' claim as false advertising if the product actually contains synthetic ingredients, since it misleads a reasonable consumer.
Does listing a synthetic ingredient in the ingredient list excuse a "natural" claim? No. In its enforcement actions, the FTC has explicitly rejected the argument that a technically accurate ingredient list cures a misleading 'all natural' claim made prominently elsewhere on the packaging or website — a small-print disclosure buried in a long ingredient list doesn't offset a bold marketing claim.
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