What does "natural flavors" mean on a supplement label?

Q: Why won't a brand just say what's in their "natural flavors"?

The law doesn't require it past that one line. The exact blend is typically the flavor supplier's formulation, not something the brand buying it was ever handed in full.

September 11, 2026

Vanilla-flavored whey protein isolate tub with powder

"Natural flavors" is a legal category, not one ingredient. Under FDA rule 21 CFR 101.22, it means any flavoring extracted from a plant, animal, or dairy source rather than synthesized from scratch. One label line can cover a blend of dozens of compounds, plus carriers the rule doesn't require anyone to name.[1][2][5]

AUROM's own whey label is three lines: whey protein isolate, natural flavors, stevia extract (leaf). Two of those are easy to picture. The third is the one line that stays vague no matter how transparent the rest of the label is.

What does the FDA actually mean by "natural flavor"?

The rule is 21 CFR 101.22(a)(3). Natural flavor is defined as "the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose significant function in food is flavoring rather than nutritional."[1][7]

Artificial flavor, defined right next to it in the same section, is the mirror image: any flavor-imparting substance that is not derived from those sources.[1] The entire line between "natural" and "artificial" is where the starting material came from. It says nothing about how the flavor was processed once extracted. Roasting, heating, and enzymolysis are all named in the rule itself and all still count as natural. It says nothing about how many substances are in the blend, and it says nothing about purity. A label can say "natural flavors" and be legally correct whether that line is one compound or fifty.

Why can one line cover dozens of compounds?

Flavor chemists (flavorists, in the trade) build flavors from a large shared palette, not from a single extracted essence. One food-science explainer puts the size of that palette at "more than 3,000 different chemicals, mixtures, and extracts," and makes the point with fruit: "a real strawberry may contain hundreds of compounds that together add a unique depth in flavor," while only a handful of those compounds are what most people would recognize as "tasting like strawberry."[2] A chemical analysis of the industry's own approved list for flavor chemicals counted 2,244 separate compounds on the list current at the time of that paper.[3]

The flavor industry has a name for a characterized multi-compound mixture like this: a natural flavor complex, or NFC. A 2023 safety re-evaluation by the Flavor and Extract Manufacturers Association's expert panel describes a program, begun in 2015, to review "over 250 natural flavor complexes" used as flavor ingredients, working from a full characterization of each complex's constituents, sorting those constituents into chemically related groups, and then affirming the complex as a whole.[4] That's the scale behind a single ingredient line. "Natural flavors" on a supplement tub is shorthand for a formulation, usually proprietary to the flavor house that sold it to the brand, not a single named substance the brand chose.

What's allowed to ride along without being named?

Beyond the flavor constituents themselves, a flavor blend typically needs something to carry, dilute, or stabilize it so it mixes into water, coffee, or a shake the way it's supposed to. Under 21 CFR 101.100, an incidental additive that's present at an insignificant level and has no technical or functional effect in the finished food doesn't have to be declared on its own, even if it had a functional effect inside the flavor ingredient that carried it in.[5] In plain terms: a carrier or solvent can be present in the tub and never appear on the panel, because the rule doesn't require a brand (or its flavor supplier) to name it separately from "natural flavors."

No brand had to invent that loophole. It's the shape of a regulation written for an industry where flavor formulations are usually trade secrets belonging to the flavor house, not the company putting a scoop in a tub.

What "natural" does and does not guarantee

FDA has never finalized a formal definition for the word "natural" standing alone, only a longstanding policy describing it as meaning "nothing artificial or synthetic... has been included in, or has been added to, a food that would not normally be expected to be in that food." The agency has also said plainly what that policy was never meant to cover: it "was not intended to address food production methods, such as the use of pesticides," it "did not explicitly address food processing or manufacturing methods," and FDA "did not consider whether the term 'natural' should describe any nutritional or other health benefit."[6]

That's the general word "natural." The flavor-specific rule in 101.22 runs on the same logic: it tracks where the material came from, not how healthy, how pure, or how simple the result is. Two things follow from that:

"Natural" is not a health or safety claim. Nothing in either rule says a natural flavor is better for you than an artificial one, only that it started somewhere different.
"Natural flavors" doesn't tell you the source is plant-based. The FDA definition explicitly includes flavoring "derived from... meat, seafood, poultry, eggs, dairy products," so a vegan or allergy-conscious reader can't assume plant origin from that line alone.[1]

AUROM's own label, walked through

AUROM's Whey Protein Isolate ingredient list is whey protein isolate, natural flavors, stevia extract (leaf), the same three lines on both Chocolate and Vanilla, even though the two flavors' supplement facts differ.[8] Whey protein isolate is the protein. Stevia extract (leaf) is the sweetener, and it's named outright rather than folded into the flavor line.

"Natural flavors" is the one line we can't take further than the regulation requires. We didn't blend it ourselves, and we can't hand you a breakdown the law doesn't ask our flavor supplier to give us. That's the edge of what any label, including a three-line one, is allowed to say, not a gap we chose to leave open. So we won't pretend we can see past that line. What we will do is keep everything else on the label from hiding behind a blend name the way that one line legally can. That instinct is the whole reason the rest of our label reads the way it does: one ingredient named, one dose printed, nothing folded into a proprietary mix to avoid saying what's in the tub.

If you want the rest of the label explained the same way, line by line, how to read a supplement label covers the whole panel. The other line that hides more than it shows is a proprietary blend, which is a different problem with a similar shape: a single line standing in for something a label doesn't have to spell out.

The honest questions to ask a brand

A few questions separate a brand that's thought about this from one that hasn't:

Can you tell me, or can your flavor supplier tell me, what's actually in your "natural flavors" line, even though the label doesn't require it?
Is that flavor derived from dairy, egg, or another animal source I should know about for an allergy or a vegan diet?
Is "natural flavors" the only vague line on the label, or is there also an unnamed proprietary blend somewhere else on the panel?

None of those questions have a legal answer a brand owes you. They have an honesty answer, and that's the one worth judging a brand on.

FAQ

Is "natural flavor" the same thing as "natural flavoring"? Yes. FDA's rule treats the two terms as interchangeable. Both describe flavoring material derived from a spice, fruit, vegetable, herb, meat, dairy, or similar source rather than synthesized from scratch.[1]

Can "natural flavors" contain synthetic substances? Yes, in a specific, narrow sense. Carriers or solvents with no separate technical effect in the finished product are incidental additives under 21 CFR 101.100 and don't need their own line, even if they weren't naturally derived themselves.[5]

Does "natural" mean a product is healthier or safer? Not according to FDA. Its own guidance on the word says the concept doesn't address nutritional or health benefit, production method, or processing technique. It tracks where the material came from, nothing else.[6]

Is "natural flavor" vegan or allergen-free? Not necessarily. The FDA definition explicitly allows flavoring derived from meat, seafood, poultry, eggs, or dairy products, so the line alone doesn't tell you the source without asking.[1]

Why won't a brand just say what's in their "natural flavors"? The law doesn't require it past that one line.[1][5] The exact blend is typically the flavor supplier's formulation, not something the brand buying it was ever handed in full.

The short version

"Natural flavors" will stay one vague line on every supplement label you read, including ours. That's what 21 CFR 101.22 allows and what the flavor supply chain makes practical. What you can judge is the rest of the panel: whether every other line names what it is and how much, and whether the brand answers when you ask about that one.

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.