What is Red 40, and why is it in so many foods?
Red 40 is a synthetic food dye (also called Allura Red AC, or E129 in Europe) derived from petroleum. It belongs to the azo dye family, a class of synthetic colorants that share a nitrogen-nitrogen double bond. It produces a bright red to orange-red color and is one of the most commonly used artificial colorants in the food supply.
Despite the name, it doesn't always make food look red. Depending on the formulation, it can produce orange, pink, or purple tones. Many products listed as "cherry," "strawberry," or "fruit punch" flavored get their color partly or entirely from Red 40.
It's water-soluble, stable under acidic conditions, and inexpensive, which is why it shows up so widely. Unlike natural colorants (beet juice, annatto), synthetic dyes like Red 40 don't fade with heat or light exposure, making them reliable for processed food manufacturing.
Where it shows up
Red 40 is in a wider range of products than most people expect:
- Fruit-flavored cereals and cereal bars
- Sports and energy drinks
- Gummies, hard candies, and fruit snacks
- Gelatin desserts and pudding mixes
- Strawberry and cherry flavored yogurt
- Some fruit juices and juice drinks
- Certain flavored chips and snack crackers
- Maraschino cherries
- Some medications and vitamins (particularly children's formulations)
It shows up on labels as "Red 40," "Red 40 Lake," or "FD&C Red No. 40." The "Lake" version is an oil-dispersible form used in products where you need color in a fat-based medium. Many of these same products also contain other additives flagged by the NOVA ultra-processed food classification, where synthetic colors are one of several markers used to identify Group 4 industrial formulations.
Is Red 40 in over-the-counter children's medication?
Yes. Red 40 is a common colorant in liquid OTC medications and chewable tablets marketed to children, used to make the product visually appealing and (manufacturers argue) to encourage children to take it. The exposure route is one most parents don't think to check.
Common OTC children's formulations where Red 40 can appear:
- Liquid diphenhydramine (children's allergy and sleep aids)
- Some liquid ibuprofen formulations in "berry" or "fruit punch" flavors
- Some liquid acetaminophen in cherry or strawberry variants
- Chewable and gummy multivitamins for children
- Some throat syrups and lozenges marketed to children
The same disclosure rules that apply to food apply here: Red 40 must be listed by name in the inactive ingredients section of the drug facts label. Dye-free versions are available for most common children's OTC medications and are sold at major pharmacies, typically labeled explicitly as "dye-free."
If your child has ADHD, aspirin sensitivity, or a documented salicylate intolerance, checking medication labels matters as much as checking food labels. The behavioral and sensitivity research was based on dietary exposure, but medication is an additional source that's easy to overlook when trying to reduce total intake.
How much Red 40 is in a typical Skittles serving?
That number is not on the label. US and Canadian labeling rules require that Red 40 be disclosed by name, not by quantity, so manufacturers are under no obligation to tell you how much is in a serving.
A 2021 California EPA dietary dye exposure review (published by OEHHA) examined how much synthetic dye children typically consume across food categories. The review identified mixed fruit candy as one of the higher-exposure sources, but because manufacturers don't disclose dye quantities per serving, exact per-product figures aren't publicly available.
The FDA's Acceptable Daily Intake (ADI) for Red 40 is 7 milligrams per kilogram of body weight per day. For a 25-kilogram child (about 55 pounds), that ceiling is 175 milligrams daily. A single candy serving stays below it. The concern is cumulative: a child who eats dyed candy, drinks a colored beverage, takes a flavored vitamin, and receives a colored liquid medication in the same day is drawing Red 40 from four separate sources. Because no label shows the quantity, tracking total daily exposure requires deliberate effort.
Does Red 40 cause hyperactivity in children?
The most significant ongoing controversy around Red 40 involves behavior in children. In 2007, a study published in The Lancet found that a mixture of food colorings (including Red 40, along with five other dyes) plus sodium benzoate (a common preservative) was associated with increased hyperactivity in children.
The UK's Food Standards Agency reviewed this research and concluded the evidence was strong enough to recommend that manufacturers voluntarily remove the six colorings studied. The European Union went further: products containing any of these six dyes must now carry a label warning that the product "may have an adverse effect on activity and attention in children."
The EU warning label reads: "may have an adverse effect on activity and attention in children." This is a required statement for any food in the EU containing Red 40, not just a voluntary caution.
The FDA reviewed the same research and concluded it did not establish a causal link between the dyes and hyperactivity in the general population. They noted that a subset of children with ADHD may be sensitive to these dyes, but declined to require labeling or remove the dyes from the approved list.
As of 2026, Red 40 remains on the FDA's approved list with no required warning label in the United States or Canada. That regulatory gap is consistent with how North America and Europe differ on other additives, including titanium dioxide (E171), which the EU banned from food in 2022 while the FDA still permits it. Consumer pressure has started moving some big brands ahead of the regulators: Gatorade dropped Red 40 and Yellow 5 without any US rule change requiring it.
US states have begun acting independently. West Virginia passed a law in 2025 restricting certain artificial food dyes in school meals. California's food safety legislation has applied pressure on manufacturers to reformulate ahead of any federal action. These moves reflect a public sentiment shift even while the FDA's position has not changed.
The sensitivity question
Even if Red 40 doesn't affect most children in a measurable way, the evidence suggests some individuals (particularly those already diagnosed with ADHD) may be more reactive to synthetic dyes as a group.
This is where the research gets complicated. It's difficult to run a clean controlled trial on children's behavior. Parental perception of hyperactivity is subjective. And the original Lancet study tested a combination of dyes plus a preservative. It wasn't a clean test of Red 40 alone.
What the research doesn't show is a strong, consistent, population-level effect in healthy children with no pre-existing attention difficulties. What it does suggest is that some children may benefit from reducing synthetic dye intake. The evidence for a population-wide ban is weaker than the EU's decision implies; the evidence for some sensitivity in a subset of children is stronger than the FDA's inaction implies.
Red 40 allergy: who is at risk?
Red 40 is not a protein, so it does not trigger true IgE-mediated food allergies in the way peanuts or shellfish do. However, it can cause allergic-type reactions in certain individuals.
The most documented risk group is people with aspirin sensitivity or salicylate intolerance. Azo dyes like Red 40 share some chemical similarities with salicylates, and cross-reactivity has been reported. Reactions can include hives, itching, skin flushing, nasal congestion, or in rare cases, more severe symptoms.
If you have aspirin sensitivity: Azo dyes including Red 40 may trigger reactions. This cross-reactivity is documented but not universal. If you have noticed reactions after consuming brightly colored processed foods, it is worth tracking which products are involved and discussing with your doctor.
There are also anecdotal reports of reactions in people without known aspirin sensitivity, though these are harder to separate from other ingredients in the same product. Red 40 is rarely the only additive in a highly processed (NOVA Group 4) product. If you suspect Red 40 specifically, the cleanest test is a temporary elimination period followed by controlled reintroduction, guided by a healthcare provider.
The allergy risk is one reason some parents and adults prefer to avoid Red 40 even without a formal diagnosis. Avoiding it requires nothing more than reading the ingredient label, where it is always listed explicitly by name.
Other safety concerns
Beyond hyperactivity and allergy risk, some researchers have raised questions about potential carcinogenicity and genotoxicity based on animal studies. These concerns have been reviewed by regulatory agencies, and the current scientific consensus at the FDA and EFSA is that Red 40 is not carcinogenic at typical intake levels.
What EFSA's review concluded: Red 40 (E129) is acceptable for use in food and does not raise carcinogenicity concerns based on available data. The hyperactivity question is treated separately from the broader safety profile.
Why do the EU and FDA disagree on Red 40?
The US and Europe have taken meaningfully different positions on Red 40. This isn't unique: the same gap exists for several other additives and is a consistent feature of how the two regulatory systems approach uncertainty.
The EU's approach tends toward precaution: when evidence of potential harm exists, even if inconclusive, require disclosure or restrict use. The FDA's approach requires a higher bar of demonstrated harm before action.
Neither position is obviously wrong. They reflect different values around how much risk society is willing to accept without clear evidence of harm, and who bears the burden of proof: the manufacturer or the regulator.
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What FDA action did the agency take on Red 40 in 2025?
Red 40 remains approved under 21 CFR 74.340 as of May 2026. The FDA has not revoked its authorization. However, in April 2025, the FDA announced a plan to eliminate petroleum-based synthetic dyes from the food supply through two mechanisms: a voluntary phase-out of six dyes (Red 40, Yellow 5, Yellow 6, Blue 1, Blue 2, and Green 3) by the end of 2026, and initiation of formal revocation proceedings for two additional dyes, Orange B and Citrus Red No. 2.
The announcement was voluntary: the FDA set a target of 2026 for major manufacturers to begin reformulating. It was not a ban or a revocation of Red 40's approved status. Red 40 remains technically legal in the US while the voluntary transition proceeds. Red 3 is the only red dye to have had its food-use approval formally revoked, which happened earlier in 2025.
The announcement cited behavioral research as part of the agency's rationale, including the Lancet evidence base that had informed prior reviews. A separate line of concern comes from genotoxicity research: a 2023 study by Zhang and colleagues in Toxicology Reports found that Red 40 caused DNA strand breaks in cell models at concentrations within normal dietary intake ranges. That study was not part of the FDA press release, but it is part of the broader scientific conversation that preceded the voluntary phase-out decision. The FDA characterized the overall body of evidence as warranting further review rather than triggering an immediate ban, consistent with the agency's historically high evidentiary threshold for regulatory action.
How fast manufacturers move will vary by category. Beverages and candy face the clearest consumer and retailer pressure. OTC medications and supplements that use Red 40 as an inactive colorant follow a separate regulatory pathway and may not be on the same voluntary timeline.
How does Red 40 compare to other red food dyes?
Red 40 and Allura Red AC are the same compound. "Allura Red AC" is the scientific name. In Europe it is labeled E129. In the US it appears as FD&C Red No. 40 or simply Red 40. All three names refer to the same chemistry. Red 3 is a completely different dye, with a different chemical structure, different color, and a different regulatory outcome.
| Feature | Red 40 / Allura Red AC / E129 | Red 3 / Erythrosine / FD&C Red No. 3 |
|---|---|---|
| Chemical class | Azo dye, petroleum-derived | Xanthene dye, iodine-based |
| Color | Orange-red to bright red | Deep cherry red, vivid pink |
| US status (2026) | Approved; voluntary phase-out in progress | Food use revoked by FDA in 2025 |
| EU status | Permitted; products must carry behavioral warning label | Permitted only in certain cocktail cherries |
| Primary concern | Behavioral effects in children (Lancet, 2007); genotoxicity (Zhang et al., 2023) | Thyroid tumors in high-dose rat studies |
| FDA Acceptable Daily Intake | 7 mg/kg body weight per day | None (revoked) |
| Label names | "Red 40," "Red 40 Lake," "FD&C Red No. 40," "E129," "Allura Red AC" | "Red 3," "FD&C Red No. 3," "Erythrosine" |
| Common uses | Candy, beverages, cereals, children's medications and vitamins | Formerly maraschino cherries, candied fruit |
For most consumers: Red 3 is the dye that has already been removed from most US food products, while Red 40 is still widely present and under increasing pressure to reformulate.
How to check what's in your food
Red 40 is easy to find on a label once you know what to look for. It's always listed by name ("Red 40" or "Red 40 Lake"), so there's no hidden alias issue. The problem is that most people don't read labels carefully enough to catch it, especially in products where you don't expect artificial color (some "natural" sounding products contain it). If you'd rather not squint at every package, our roundup of the best food additive checker apps compares the scanner tools that flag Red 40 (and dozens of other additives) automatically.
The app reads ingredient labels with your camera and shows you every additive in seconds.
How much Red 40 is in a typical serving of candy?
The FDA sets an Acceptable Daily Intake (ADI) for Red 40 at 7 milligrams per kilogram of body weight per day under 21 CFR 74.340. For a 10-year-old weighing 70 pounds (32 kg), that's about 224 mg per day.
But here's the problem: red-dyed products don't list the amount of Red 40 in the ingredients. You know it's there, but not how much. A single serving of fruit-flavored cereal might contain 5-15 mg. A sports drink could have 10-20 mg. A pack of red gummies could have 30-50 mg. When kids consume breakfast cereal, fruit juice, and candy on the same day, cumulative intake can easily exceed 100 mg without any label warning that it's happening.
The FDA designed the ADI to be conservative (with a 100-fold safety margin built in), so exceeding it occasionally is unlikely to cause harm. But the lack of quantitative labeling means parents can't actually track their child's exposure. This gap is one reason some researchers argue for mandatory labeling of colorant concentration, similar to sodium or sugar labeling.
What did the FDA and state regulators do on Red 40 in 2025?
Red 40 itself remains approved under 21 CFR 74.340 at the federal level, with no change in FDA status as of 2026. The agency still calls it safe for the general population.
However, 2025 brought significant action on another dye in the same family. The FDA finalized the revocation of Red 3 (erythrosine) for food use on January 15, 2025, effective January 15, 2027 (Federal Register 2025-00830). Red 3 had been used in maraschino cherries, candy, and some processed foods. The revocation was based on animal studies showing thyroid cancer in male rats, and the FDA invoked the Delaney Clause, which prohibits any food additive that has been found to induce cancer in animals or humans.
At the state level, California's AB 2316 (signed September 30, 2024, effective December 31, 2027) restricts four synthetic dyes including Red 40 from school meals. West Virginia passed a school meal restriction on artificial dyes in 2025. These moves signal growing pressure on manufacturers even without federal action, and Red 40 appears to be in the regulatory crosshairs, even if it's not yet revoked.
Is Red 40 in over-the-counter children's medication?
Yes. Red 40 is found in many OTC medications marketed to children: ibuprofen and acetaminophen liquid suspensions (both branded and generic), diphenhydramine antihistamine syrups, cough and cold syrups, and chewable multivitamins. It appears in the inactive ingredients list, usually toward the end. Parents treating a fever or cold may inadvertently add Red 40 to a child's daily exposure on top of any red-dyed foods consumed that day.
This is not required; dye-free formulations exist for most common OTC children's medications. If you want to avoid Red 40, check the inactive ingredients list on the bottle. If you see "FD&C Red No. 40," "Red 40," "Allura Red," or "Red 40 Lake," choose a dye-free version instead. Many pharmacy chains and manufacturers now label dye-free options prominently on the front of the package.
For children with ADHD, aspirin sensitivity, or a parent's preference to avoid synthetic additives, selecting dye-free medication is a simple way to reduce total intake without needing a prescription change.
Frequently asked questions about Red 40
Quick answers to the questions that come up most often about this dye.
Is Red 40 banned in Europe?
Red 40 is not banned in the EU, but any food containing it must carry a warning label: "may have an adverse effect on activity and attention in children." This is a required statement, not voluntary. The UK's Food Standards Agency also asked manufacturers to voluntarily remove it after the 2007 Lancet study.
What foods contain Red 40?
Red 40 shows up in fruit-flavored cereals, sports drinks, gummies and candy, strawberry or cherry flavored yogurt, gelatin desserts, some fruit juices, maraschino cherries, and many children's vitamins and medications. It's listed as "Red 40," "Red 40 Lake," or "FD&C Red No. 40."
Does Red 40 cause hyperactivity?
The 2007 Lancet study linked a mix of six food dyes (including Red 40) plus sodium benzoate to increased hyperactivity in children. The EU accepted this evidence and added warning labels. The FDA concluded the evidence did not establish a causal link for the general population but acknowledged some children with ADHD may be sensitive. So the honest answer: it may affect some sensitive children, but not most.
Is Red 40 carcinogenic?
Current scientific consensus at both the FDA and EFSA is that Red 40 is not carcinogenic at typical intake levels. Some animal studies have raised questions, but these have been reviewed by regulatory agencies and not considered sufficient evidence for restriction on cancer grounds.
What's the difference between Red 40 and Red 3?
Red 3 (erythrosine) is a separate dye that was banned from cosmetics in the US in 1990 over cancer concerns in rat studies, but it remained legal in food until the FDA finally revoked its food use approval in 2025. Red 40 is a different chemical that has never been banned in the US, though it's more controversial than most people realize.
How can I avoid Red 40?
Read ingredient labels. Red 40 is always listed by name, never hidden under "natural flavor" or a vague term. Products marketed as "organic" in the US cannot contain synthetic colors, so certified USDA Organic is a safe bet. Apps like NoJunk scan labels with your phone camera and flag Red 40 automatically so you don't have to squint at every package.
Is Red 40 safe?
For most healthy adults, Red 40 is considered safe at typical dietary intake levels by both the FDA and the European Food Safety Authority (EFSA). Neither agency has found evidence of harm at the amounts found in a normal diet.
The EU requires a warning label on foods containing it because of a 2007 study linking a combination of food dyes (including Red 40) to increased hyperactivity in some children. Some people with aspirin or salicylate sensitivity may also experience allergic-type reactions.
Whether it is safe for you depends on your individual health context. If you have children with attention difficulties, or a known salicylate sensitivity, reducing Red 40 intake is a reasonable precaution even without a medical directive.
What type of food dye is Red 40?
Red 40 is a synthetic azo food dye, also known as Allura Red AC or E129 in Europe. "Azo" refers to its chemical structure, which contains a nitrogen-nitrogen double bond. It is petroleum-derived and water-soluble, which makes it stable and easy to use in a wide range of packaged foods.
In the US it is approved as FD&C Red No. 40 and regulated by the FDA. It is one of eight certified food color additives (synthetic dyes) currently approved for use in US food products.
Can Red 40 cause an allergic reaction?
Yes, Red 40 can cause allergic-type reactions in some people. It is not a protein, so it does not trigger a classic IgE-mediated allergy the way peanuts or eggs do. However, people with aspirin sensitivity or salicylate intolerance may experience cross-reactive symptoms from azo dyes like Red 40.
Reported reactions include hives, itching, skin flushing, and nasal symptoms. Severe reactions are rare. If you suspect Red 40 is causing symptoms, a temporary elimination period followed by reintroduction (under medical guidance) is the most reliable way to test it.
Is Red 40 the same as Red Dye 40?
Yes. "Red 40," "Red Dye 40," and "FD&C Red No. 40" all refer to the same compound. The scientific name is Allura Red AC. In the EU it is labeled E129. You may also see "Red 40 Lake," which is the oil-dispersible form used in fat-based products like coatings and some medications. All of these names refer to the same synthetic azo dye derived from petroleum.
What products use Red 40 in Canada vs. the US?
Both the US and Canada approve Red 40 for use in food, beverages, and OTC medications under similar conditions. Health Canada's permitted food additives list allows it in the same product categories as the FDA's approval: fruit-flavored candy, cereals, beverages, gelatin desserts, maraschino cherries, and children's medications and vitamins.
One difference: in Canada the dye is declared by its Canadian common name, "Allura Red" (Health Canada also permits the form "Allura Red (Red 40)"), and because Quebec requires a French ingredient declaration, the French list shows "rouge allura." Neither country requires manufacturers to disclose the quantity, only the presence by name.
How much Red 40 is in a typical candy serving?
The exact amount is not on the label. Neither the FDA nor Health Canada requires quantity disclosure for color additives. A 2021 California EPA dietary dye exposure review identified candy as a high-exposure category for children, but per-product figures require lab analysis that manufacturers don't publish.
The FDA's Acceptable Daily Intake is 7 mg per kilogram of body weight per day. A child weighing 25 kg has a daily ceiling of about 175 mg. A single candy serving typically falls below that, but a child who also drinks a dyed beverage, takes a flavored vitamin, and receives a colored liquid medication the same day is drawing from multiple sources simultaneously, with no individual label showing how much is in each item.
Is Red 40 the same as Red Dye 40?
Yes, all names (Red 40, Red Dye 40, FD&C Red No. 40, Allura Red AC, E129) refer to the same substance. The EU requires a warning label stating "may have an adverse effect on activity and attention in children." The US does not require such a label, even though the underlying substance is identical.
What products use Red 40 in Canada vs. the US?
Red 40 is approved in both Canada and the US for the same food categories: soft drinks, candy, baked goods, dairy desserts, breakfast cereals, condiments, and fruit snacks. Health Canada lists it as Allura Red or Red 40 under schedule B.16.100. US versions of the same branded products sometimes use heavier dye concentrations than their Canadian equivalents, even though both are legal under each country's standards.
Which children's medicines commonly contain Red 40?
Ibuprofen and acetaminophen suspensions, diphenhydramine syrups, cough and cold liquids, and chewable multivitamins. Red 40 appears in the inactive ingredients toward the end of the list. Dye-free versions are available; look for a label on the front of the package or check for FD&C Red No. 40, Allura Red, or Red 40 Lake in the inactive ingredients.
The bottom line
Red 40 is not definitively proven to be harmful to most people at typical intake levels. That's an honest reading of the current evidence.
What's also true: the EU has decided the potential effect on children's behavior is sufficient to require a warning label. That's a reasonable position given the Lancet research. And if you have a child with ADHD or attention difficulties, the evidence is strong enough that removing synthetic dyes is worth trying, even if it's not proven to help in every case.
The goal isn't to make you anxious about everything on the label. It's to make sure you can see what's actually there.
Last reviewed: May 2026