Is red dye in M&M's safe? Unpacking the Controversy and Science

January 8, 2026 •

4 min read

In 1976, Mars temporarily removed red M&M's from production due to public concern over a different red dye. Today, many still question if red dye in M&M's is safe, often focusing on the commonly used Red Dye 40, known as Allura Red AC.

Quick Summary

This article examines the safety of red dye, specifically Red Dye 40, found in products like M&M's. It reviews the regulatory status, scientific studies linking it to potential health risks like behavioral issues and inflammation, and the differing global approaches to its use.

Key Points

Dye is FD&C Red No. 40: M&M's sold in the U.S. contain FD&C Red No. 40 (Allura Red AC), a synthetic, petroleum-derived food coloring, not the once-banned Red No. 2.
FDA deems it safe: The U.S. Food and Drug Administration (FDA) has approved Red Dye 40 for consumption within specific limits.
Linked to hyperactivity in some kids: Some studies, including the prominent Southampton study, link Red Dye 40 to increased hyperactivity and ADHD symptoms in sensitive children, though not in the general population.
Associated with other health concerns: Concerns have been raised based on animal studies linking Red 40 to gut inflammation, altered gut microbiome, and potential DNA damage.
Global regulatory differences: While the U.S. approves Red Dye 40, many European countries require warning labels on products containing it regarding effects on children's behavior.
Natural alternatives exist: Manufacturers, including Mars, are increasingly using natural colorants like beet juice, paprika, or cochineal for products sold in stricter markets.
Old scare was different dye: A 1976 scare that led Mars to remove red M&M's involved a different dye (Red No. 2), even though M&M's never used it.

A History of Red Dye in M&M's: The 1976 Scare

The perception surrounding red dyes is not a recent phenomenon. In the mid-1970s, a public scare over FD&C Red No. 2 (amaranth) led to its ban by the FDA due to a Russian study suggesting it was carcinogenic in rats. Although M&M's never contained Red No. 2, Mars, the manufacturer, proactively pulled red M&M's from the market to avoid consumer anxiety. The red candies were not reintroduced until 1987, more than a decade later. This incident cemented public wariness of synthetic food colorants, a sentiment that continues with modern discussions surrounding Red Dye 40.

What is Red Dye 40 and is it in M&M's?

Red Dye 40, also known as Allura Red AC, is a synthetic food coloring derived from petroleum. In the United States, it is one of the most widely used color additives, approved by the Food and Drug Administration (FDA). Yes, M&M's sold in the U.S. do contain FD&C Red No. 40, as explicitly listed on ingredient labels. The FDA mandates that all certified color additives, like Red 40, must be listed on a product's label.

The Health Debate: Red Dye 40 Risks

While the FDA considers Red Dye 40 safe for consumption within specified limits, a significant debate exists surrounding its potential health effects, particularly in children. This controversy has led some consumer advocacy groups and individuals to call for further restrictions or outright bans, mirroring regulations in some other countries.

Hyperactivity and Children's Health

For years, a potential link has been studied between artificial food dyes and hyperactivity, especially in sensitive children with conditions like ADHD. A landmark 2007 study in Southampton, UK, found an association between certain artificial dyes (including Allura Red AC) and increased hyperactivity. While the effects are often described as modest, and not all children are affected, some families report notable improvements in behavior when these dyes are removed from their diet. In response to this and other studies, European regulations now require a warning label on products containing Red Dye 40 and other artificial colorants, stating they "may have an adverse effect on activity and attention in children". The U.S. FDA, however, has stated that while some children may be sensitive, the evidence does not support a general population risk.

Other Potential Health Concerns

Allergic Reactions: Although rare, some individuals may experience allergic reactions to Red Dye 40, with symptoms ranging from hives and skin irritation to asthma-like symptoms and swelling.
Digestive and Inflammatory Issues: Recent animal studies have suggested that Red Dye 40 can have negative effects on gut health. A 2023 study found that continuous exposure to Red Dye 40 caused low-grade colonic inflammation and altered the gut microbiome in mice, potentially increasing susceptibility to inflammation. While these animal results require more research in humans, they raise concerns about long-term consumption.
DNA Damage and Carcinogen Contamination: Some researchers have raised concerns about DNA damage from Red Dye 40, noting that it contains trace amounts of known or suspected carcinogens from the manufacturing process, such as benzidine. A 2023 study even found that Red 40 caused DNA damage in lab cells and living animals.

Red Dye 40 vs. Natural Alternatives

While Red Dye 40 is a synthetic, petroleum-derived substance, natural red colorants exist and are used by many manufacturers, particularly for products sold in Europe. Mars recently announced efforts to shift towards more natural alternatives, a move aligned with consumer preferences for cleaner labels.


Feature	FD&C Red No. 40 (Allura Red AC)	Natural Red Colorants	Carmine (Cochineal)	Beet Juice
Source	Petroleum distillates/coal tars	Varies: Plant or insect-based	Female cochineal insects	Beetroot (Beta vulgaris)
Usage in M&M's	Used in U.S. formulations	Used in European formulations	Used in European M&M's	Not standard for M&M's, but used in other food items
Regulatory Status (US)	FDA approved, must be labeled	FDA-exempt, but specific exceptions apply (e.g., carmine)	Must be declared as 'carmine' or 'cochineal extract' due to potential allergic reactions	Considered safe, used widely
Associated Health Concerns	Hyperactivity, allergies, potential inflammation and DNA damage (based on some studies)	Limited, but rare allergic reactions can occur with some natural dyes	Can cause severe allergic reactions in some individuals	Generally considered safe, though high intake may cause red urine (beeturia)
Color Consistency	Highly consistent, stable, and vibrant	Can be less stable and fade over time; color may vary by source	Strong, deep crimson	Rich red to pink

How to Limit Red Dye Exposure

For those concerned about Red Dye 40, limiting exposure is a matter of reading labels and opting for alternatives. The FDA requires the specific color additive to be listed, so look for “FD&C Red No. 40” or “Red 40” on the ingredients list. Avoiding heavily processed and brightly colored foods is often a good strategy, as these are the most common sources of synthetic dyes. Many organic and natural food brands use alternatives like beet juice or paprika for coloring.

Conclusion

The question of whether is red dye in M&M's safe is nuanced and involves a mix of historical context, scientific research, and ongoing consumer concerns. The specific dye used, Red Dye 40, has been deemed safe by U.S. regulatory bodies but continues to be a topic of controversy. While definitive human evidence of severe harm is limited and inconclusive for most people, some studies suggest potential risks, particularly for sensitive children. For consumers seeking to minimize or avoid synthetic dyes, a variety of alternatives exist, and many food companies are already transitioning to natural colorants in response to market trends. The best approach is to stay informed, read labels, and make choices that align with personal health preferences and comfort levels.

Center for Science in the Public Interest (CSPI) on Food Dyes

Frequently Asked Questions

Red M&M's were removed from the market in 1976 due to consumer fear over a different dye, FD&C Red No. 2, which was banned based on controversial studies. Although M&M's did not use Red No. 2, the company removed the red color to avoid negative consumer sentiment.

No, Red Dye 40 is a synthetic dye derived from petroleum. The red dye often rumored to be from insects is carmine or cochineal extract, which is derived from female cochineal insects and used as a natural alternative in some products, including European M&M's.

Some studies have suggested links between Red Dye 40 and hyperactivity, allergic reactions (though rare), and digestive issues like inflammation based on animal research. However, the FDA states that for most people, it poses no known health risks within approved limits.

In the U.S., Red Dye 40 must be clearly listed on a product's ingredient label. Look for "FD&C Red No. 40," "Red 40," or "Allura Red AC".

Red Dye 40 is not banned in most countries but is subject to stricter regulations elsewhere. The European Union requires products containing it to carry a warning label about potential effects on children's attention and activity, and some food companies use natural alternatives instead.

Some research suggests that eliminating artificial food dyes, including Red 40, from the diet may lead to modest but statistically significant improvements in hyperactivity symptoms in some sensitive children, particularly those with ADHD. Discussing this with a healthcare provider is recommended.

Yes, many natural alternatives exist and are widely used. Common examples include beet juice, paprika extract, and carmine, which is used in European candies.