What Are “Natural Flavors”? The FDA Loophole Inside Every Label
“Natural flavors” is the third most common ingredient listed on U.S. food labels — appearing in everything from protein bars to baby food. But under FDA regulation 21 CFR 101.22, the term can legally conceal over 100 distinct compounds. No individual disclosure required. Here is what the regulation says, what it permits, and what it cannot tell you.
Bottom line
What the FDA definition actually says
Under 21 CFR 101.22(a)(3), a “natural flavor” is defined as the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating, or enzymolysis — derived from plant or animal material whose significant function in food is flavoring rather than nutritional. That is a deliberately broad definition.
The critical phrase is “significant function in food is flavoring.” Compounds present at low concentrations whose primary role is taste or aroma — even if they also carry nutritional or physiological effects — qualify under this definition. This includes glutamates, certain preservatives, and carrier solvents that accompany the flavor compound.
The Flavor and Extract Manufacturers Association (FEMA) maintains a GRAS list of over 2,700 substances permitted in natural flavor formulations. The FDA does not independently verify this list; it defers to FEMA’s self-affirmation process. This is the same GRAS framework discussed in our FDA GRAS loophole analysis.
What “natural” source categories are permitted
The FDA permits natural flavors to be derived from a specific but wide range of biological sources. The table below maps the permitted categories against examples consumers may not expect.
| Permitted source category | Example ingredients | Consumer notes |
|---|---|---|
| Spices, herbs, bark, buds | Cinnamon oil, clove extract | Clearly plant-derived, low controversy |
| Fruit / vegetable juice | Citrus terpenes, beet extract | Common in beverages |
| Meat, seafood, poultry | Chicken fat, anchovy extract | Not vegan — rarely disclosed |
| Dairy | Butter flavor from butterfat | Relevant for lactose-intolerant consumers |
| Fermentation products | Yeast extract, glutamates | Functionally similar to MSG |
| Edible organisms | Ambrette musk (plant seed) | Can include allergen-adjacent compounds |
Manufacturer flavor formulations are protected as trade secrets. Flavor houses such as Givaudan, Firmenich, and IFF supply blended formulations to food companies under confidentiality agreements. Neither the retailer nor the final label is required to disclose the composition. To learn more about how flavoring additives are classified, see our flavoring additives category.
Natural flavors vs. artificial flavors: does the distinction matter?
The regulatory distinction
An artificial flavor is defined as any substance not derived from plant or animal material — it is synthesized from petrochemical or other non-biological precursors. The FDA requires labels to distinguish between natural and artificial flavors. However, the distinction is about source, not about structure: natural and artificial vanillin (vanillin being the primary compound in vanilla flavor) are chemically identical molecules. The body processes them identically.
For a detailed comparison, see our article on natural vs. artificial food additives.
The safety evidence
No large-scale epidemiological evidence links natural flavors as a category to adverse health outcomes. Most individual flavor compounds have been tested at high doses in animal studies with no concerning results. The legitimate concern is not toxicity at typical consumption levels — it is the lack of transparency for people with specific sensitivities, allergies, or dietary restrictions.
What the EU does differently
Hidden compounds: MSG, propylene glycol, and preservatives
Three categories of compounds can legally appear inside a natural flavor declaration that many consumers specifically try to avoid.
Glutamates (functionally equivalent to MSG)
When yeast extract, hydrolyzed vegetable protein, or autolyzed yeast appears in a natural flavor formulation, it brings free glutamic acid — the same molecule that constitutes monosodium glutamate. Products labeled “no added MSG” can legally contain glutamates via natural flavors if the glutamate is not added as the purified sodium salt. Our MSG explainer covers the broader evidence on glutamate sensitivity.
Propylene glycol as a flavor carrier
Flavor compounds are often oil-soluble and need a carrier to distribute evenly in water-based food products. Propylene glycol (PG) is one of the most common carriers. It is FDA-approved as GRAS and appears in natural flavor formulations without appearing separately on the label. At the concentrations involved in flavoring (typically below 0.1% of the total product), propylene glycol is not considered a health concern for most adults.
Preservatives
Natural flavor formulations can include preservatives such as sodium benzoate or citric acid to extend the shelf life of the flavor concentrate. When these appear as minor components of a flavor blend, they are not required to appear on the finished food label — only when they serve a technical function in the finished food itself.
Regulatory developments: 2024–2026
Update — April 2026
In 2024, the FDA issued updated guidance on allergen disclosure within flavor formulations, requiring manufacturers to identify the presence of major food allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans, sesame) even when they appear as components of natural flavor formulations. This does not require disclosure of the full formulation, but it closes the most safety-critical gap for allergy sufferers.
A 2025 EWG consumer advocacy report called for mandatory sub-ingredient disclosure within natural flavor declarations. As of April 2026, the FDA has not proposed rulemaking on this issue. The current transparency gap remains.
The EFSA completed a systematic review of flavoring substances in 2023–2024, re-evaluating approximately 400 compounds for which data had been inadequate. Several substances were removed from the EU positive list as a precautionary measure. These substances may still be present in natural flavors sold in the United States if they meet the FDA’s separate GRAS criteria.
Frequently asked questions
Are natural flavors bad for you?
Not necessarily. Most natural flavors are used at very low concentrations and are considered safe by the FDA under GRAS status. The concern is transparency: consumers cannot know what specific compounds are present without contacting the manufacturer directly.
Do natural flavors contain MSG?
They can. Glutamates — the same class of compounds as MSG — are permitted processing aids under the natural flavors umbrella when derived from natural sources such as yeast extract or hydrolyzed proteins. Products labeled 'no added MSG' can still contain glutamates via natural flavors.
Is vanillin a natural flavor?
It depends on the source. Vanillin extracted from vanilla beans qualifies as a natural flavor. Vanillin synthesized from petrochemicals does not. However, vanillin derived from lignin (wood pulp) or rice bran via fermentation also qualifies as natural under 21 CFR 101.22, even though the process is highly industrial.
Are natural flavors vegan?
Not always. Natural flavors can be derived from animal products including meat, fish, dairy, or eggs. The FDA does not require manufacturers to specify the source. Products certified vegan by a third party have been independently verified to exclude animal-derived flavoring compounds.
Can natural flavors contain propylene glycol?
Yes. Propylene glycol is a permitted solvent for flavor compounds and may appear in natural flavor formulations as a carrier. It does not appear on the ingredient label separately.
Data summary — not medical advice
For a broader guide to decoding ingredient lists, see our parent’s guide to reading food labels.
Related guides
Sources
- U.S. FDA. 21 CFR 101.22 — Foods; labeling of spices, flavorings, colorings and chemical preservatives. ecfr.gov.
- Flavor and Extract Manufacturers Association (FEMA). GRAS Program Overview. femaflavor.org.
- European Parliament. Regulation (EC) No 1334/2008 on flavourings and certain food ingredients with flavouring properties. eur-lex.europa.eu.
- EFSA Panel on Food Additives and Flavourings. Systematic re-evaluation of flavouring substances. efsa.europa.eu, 2023.
- FDA Food Allergen Labeling and Consumer Protection Act (FALCPA) — Updated guidance 2024. fda.gov.
- Environmental Working Group. Consumer guide to food chemicals: natural flavors. ewg.org, 2025.
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