Red Dye 40: What It Is, FDA Status, Studies and the Dye Phase-Out

Red dye 40, also called Allura Red AC and FD&C Red No. 40, is a synthetic color additive made from petroleum-derived chemicals. It gives a bright red or orange-red shade to candy, soft drinks, sports drinks, cereals, snacks, baked goods and some flavored medicines and supplements. The FDA approves it and tests every batch before it can be sold. In April 2025, the FDA and HHS asked the food industry to remove it, along with five other synthetic food dyes, by the end of 2026. Below: what red dye 40 is, how it appears on labels, the Red No. 3 revocation, the 2025 phase-out plan, and what studies on children’s behavior actually show.

Peptide Labs does not sell food dyes; some supplements, including a few gummies and coated tablets in our store, list colors such as Red 40 among their inactive ingredients. This article is general information, not medical advice.

What is red dye 40?

Chemically, Allura Red AC is an azo dye. It becomes FD&C Red No. 40 only after a batch passes FDA certification: the identity and purity specifications are in 21 CFR 74.340, and each batch is tested under the certification rules in 21 CFR part 80. The “FD&C” prefix signals approval for foods, drugs and cosmetics. Manufacturers also use an aluminum lake form, which disperses in fats and coatings, for items like coated tablets and candy shells.

In the European Union the same color carries the code E129. Outside food, red dye 40 colors many cherry, strawberry and berry flavored liquid medicines, chewable vitamins and cosmetics.

Food dyes in the US: certified and exempt colors

FDA sorts food dyes into two groups. Certified colors are synthetic dyes, including Red 40, that must be batch tested by FDA. Colors exempt from certification come mostly from plants, minerals or animals, such as beet juice, annatto, paprika, turmeric and fruit or vegetable juices. Exempt does not mean unregulated: these colors still need FDA approval for their uses. If you like the idea of naturally red foods, our guide to beetroot covers one of the most familiar sources of red pigment.

How red dye 40 appears on labels

Under 21 CFR 101.22, certified colors in food must be declared by name in the ingredient list. A label may say “FD&C Red No. 40” or the shorter “Red 40”, since FDA allows “FD&C” and “No.” to be dropped. The lake form appears as “Red 40 Lake”. Certified colors cannot be grouped under a vague term such as “artificial color”, so if a US food contains red dye 40, the ingredient list should say so. On supplements, look under “other ingredients” below the Supplement Facts panel; on medicines, check the inactive ingredients in the Drug Facts or package insert.

Is red 40 banned? Red No. 3 and the 2025 plan for food dyes

Red 40 is not banned in the US. The dye that lost its approval is a different one, Red No. 3. On January 15, 2025, FDA revoked authorization for FD&C Red No. 3 in foods and ingested drugs under the Delaney Clause, which bars approval of a color additive shown to cause cancer in people or animals. Studies had found cancer in male rats; FDA said the way the dye causes cancer in male rats does not occur in humans, but the law left no room for discretion. Food makers have until January 15, 2027 to reformulate, and drug makers until January 18, 2028. Red No. 3 had already been barred from cosmetics and externally applied drugs in 1990.

On April 22, 2025, HHS and FDA announced a plan to phase out petroleum-based synthetic dyes. The plan included setting a national standard and timeline, beginning to revoke Citrus Red No. 2 and Orange B, and working with industry to eliminate Red 40, Yellow 5, Yellow 6, Blue 1, Blue 2 and Green 3 from the food supply by the end of 2026. That target relies on voluntary industry action; the approvals for those six dyes were not revoked by the announcement. FDA also promised faster review of natural colors, and on May 9, 2025 it approved galdieria extract blue and calcium phosphate and expanded the uses of butterfly pea flower extract. Because company timelines and FDA actions keep moving, check FDA’s color additive pages for the latest status.

States have acted too. California’s AB 418, passed in 2023, bars Red No. 3 in foods sold in the state starting January 1, 2027. California’s AB 2316, passed in 2024, bars public schools serving kindergarten through 12th grade from offering foods with Red 40, Yellow 5, Yellow 6, Blue 1, Blue 2 or Green 3, starting December 31, 2027.

Is red 40 bad for you? What studies show

Most of the debate about red dye 40 concerns children’s behavior. Here is what the main studies and reviews found, along with their limits.

The Southampton study (2007)

McCann and colleagues at the University of Southampton published a randomized, double-blind, placebo-controlled trial in The Lancet in 2007. It included 153 three-year-olds and 144 children aged eight or nine from the general population. Children drank either a placebo or drinks containing one of two mixtures of artificial colors plus the preservative sodium benzoate; one mixture included Allura red. On average, the mixtures increased hyperactivity scores, and responses varied from child to child. Because the dyes were tested as mixtures with a preservative, the study cannot show the effect of red dye 40 alone. EFSA reviewed it in 2008 and called the evidence limited, noting small effects of uncertain clinical relevance. The EU nevertheless requires foods containing any of six colors, including E129, to carry the warning “may have an adverse effect on activity and attention in children”, a rule in force since July 2010.

California OEHHA report (2021)

In April 2021, California’s Office of Environmental Health Hazard Assessment (OEHHA) released a two-year evaluation of seven FDA-approved synthetic dyes. It concluded that synthetic food dyes can cause or worsen neurobehavioral problems such as hyperactivity in some children, that children vary in sensitivity, and that the federal acceptable daily intakes rest on studies 35 to 70 years old that were not designed to detect behavioral effects.

FDA's earlier position

FDA’s Food Advisory Committee met on this question in March 2011. The panel agreed with FDA that a causal link between synthetic dyes and hyperactivity in children in general had not been established, voted narrowly that no new warning label was needed, acknowledged that some children may be sensitive, and called for more research. The 2025 phase-out plan includes an NIH research partnership on food additives and children’s health.

Put together, the research suggests that some children may react to synthetic dye mixtures, while the size and meaning of that effect are still debated. These studies do not diagnose anything. If you notice a pattern in your child’s behavior, talk with a pediatrician or other clinician, and plan any elimination diet with a clinician or registered dietitian so nutrition stays on track.

How to limit red dye 40 if you want to

• Read the ingredient list for Red 40, FD&C Red No. 40, Red 40 Lake, Allura Red or E129.
• Look for colors from beet, paprika, annatto, fruit and vegetable juice or spirulina extract instead.
• Note that carmine, a red from cochineal insects, must also be named on labels because some people are allergic to it.
• Brightly colored candy, sports drinks and frosted cereals are common sources; cutting back on them also lowers added sugar, as our guide on sugar cravings explains.
• For supplements, check “other ingredients”; gummies such as those in our melatonin gummies guide often use colors.
• For medicines, ask a pharmacist whether a dye-free version exists. Never stop a prescribed medicine on your own.

When you compare supplement labels, independent testing matters more than color; our guide to third-party tested supplements explains what the seals mean. For another common additive, see our guide to xanthan gum.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a digestive condition. 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.

Last reviewed October 2026.

Related guides: High Fructose Corn Syrup: What It Is, HFCS vs Sugar and What Studies Show, Carrageenan: What It Is, Is It Safe, and What Studies Show, Third Party Tested Supplements: What USP, NSF and Other Seals Mean.