What Is Red 40? Uses, Safety, and Pending FDA Regulations

Red 40 is a synthetic, petroleum-derived food dye currently undergoing a nationwide regulatory phase-out due to health concerns. Recent scientific research links chronic exposure to gut microbiome disruption, colon inflammation, and neurobehavioral issues in children, driving a major industry shift toward safer, natural plant-based coloring alternatives.

Key Takeaways

• National Phase-Out: The FDA and HHS have initiated a national phase-out of Red 40 and other petroleum-based food dyes, reinforced by pioneering bans in California and West Virginia.
• Gut and Brain Concerns: Recent studies, including a 2022 Nature Communications mouse study, link chronic Red 40 exposure to gut microbiome disruption and colon inflammation (colitis), and reviews link synthetic dyes to behavioral changes in some children.
• Chemical Origins: Red 40 is a synthetic azo dye derived from petroleum that is metabolized in the gut, where it can stimulate serotonin release and alter digestive tract health.
• Avoidance Strategy: Consumers can avoid Red 40 by checking labels for alternative names like FD&C Red No. 40, Allura Red AC, or Red 40 Lake, and opting for natural colorants like beet juice or paprika.

What is Red 40 and how is it made?

Red 40, chemically known as Allura Red AC, is a synthetic food dye classified as an azo dye. Unlike natural colorants derived from plants, insects, or minerals, Red 40 is synthesized from petroleum distillates or coal tars. The chemical manufacturing process involves coupling reactions of aromatic hydrocarbons, resulting in a highly stable, bright red powder that dissolves easily in water.

According to chemical databases like PubChem Allura Red AC, the final compound is a sodium salt that exhibits high resistance to light, heat, and acidity. This industrial stability makes it highly attractive to commercial manufacturers but means the compound does not easily degrade. Because it is highly purified during synthesis, it contains virtually zero nutritional value and serves an entirely cosmetic purpose in consumer products. The regulation of synthetic additives like Red 40 often runs parallel to other chemical-heavy ingredients. To learn more about how chemical stability and safety are assessed, you can read our guide: Is Benzoyl Peroxide Safe? Stability, Regulation, and Safety.

Why is Red 40 used in food and consumer products?

Food and cosmetics manufacturers use Red 40 to enhance visual appeal, restore color lost during high-heat processing, and establish product identity. Because humans associate vibrant colors with freshness and specific flavors, adding synthetic dye can make ultra-processed foods look more appetizing. It is far cheaper, more stable, and more intense than natural coloring agents.

Beyond candy, soda, and sports drinks, Red 40 is commonly added to medications, mouthwashes, toothpastes, and cosmetics like lipsticks and blushes. It often appears alongside other additives, such as synthetic flavorings. To understand how these ingredients compare to natural options, you can read our detailed guide on what are natural flavors? uses, labels, and safety explained. Because Red 40 binds easily to proteins, it is also popular in pet foods and animal feed, ensuring a consistent product appearance over long shelf lives.

Is Red 40 safe? Current regulatory and safety status

Historically, major food safety authorities like the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) have evaluated it, and both JECFA and EFSA set an Acceptable Daily Intake (ADI) of 7 milligrams per kilogram of body weight per day.

True allergic reactions to food dyes are considered rare, although some children appear sensitive to synthetic dyes, and dietary elimination trials have reported behavioral improvements in sensitive subgroups. However, regulatory consensus has fractured as clinical evidence has accumulated over the last decade.

While the FDA historically maintained that Red 40 did not pose a significant risk when consumed within the ADI, consumer advocacy groups and toxicologists have long disputed this stance. In the European Union, products containing Red 40 must carry a warning label stating the colorant may have an adverse effect on activity and attention in children. This divergence in safety standards mirrors debates surrounding other controversial food additives, such as thickeners. For more context on additive safety and changing consumer sentiment, explore our review on what is carrageenan? uses, safety, and regulatory status as well as our deep dive into dietary tolerances in what is gluten? uses, health effects, and labeling explained.

What does Red 40 do to your gut and brain?

When consumed, Red 40 is metabolized primarily in the gut by intestinal bacteria. This process can alter the delicate balance of the gut microbiome and irritate the intestinal lining. A 2022 study published in Nature Communications demonstrated that chronic exposure to Allura Red AC promotes susceptibility to experimental colitis in animal models by disrupting the mucosal barrier and stimulating excessive serotonin release. It is crucial to note that while these findings are highly suggestive of similar mechanisms in humans, this specific colitis study was conducted on animal models to maintain scientific accuracy.

This localized gut inflammation is further detailed in a related mouse immunology study on PubMed. In addition to gut health, synthetic dyes have raised neurobehavioral concerns. A 2022 review of the human and animal evidence in Environmental Health concluded that synthetic food dyes can affect activity and attention in some children, with reported effects including hyperactivity, impulsivity, and diminished attention span.

Why is the FDA phasing out Red 40?

As of July 9, 2026, the regulatory status of FD&C Red No. 40 is undergoing its most significant overhaul in decades. In April 2025, the FDA, in coordination with the Department of Health and Human Services, announced a national federal initiative to phase out petroleum-based food dyes from the national food supply chain. It is important to clarify the distinction between this federal initiative to phase out the dye and an official final ban: the initiative establishes an active administrative transition, guidelines, and industry timelines to eliminate the ingredient, whereas a final ban represents the complete, legally binding prohibition of sale and manufacturing once the phase-out period concludes.

This federal phase-out is heavily supported by pioneering state-level legislation. California led the nation with California Assembly Bill 2316, which prohibits Red 40 and other synthetic dyes in foods served in public schools. West Virginia followed in March 2025 with a comprehensive statewide ban on artificial dyes that takes effect in January 2028. These state-level mandates forced major food manufacturers to reformulate their products, paving the way for the ongoing federal transition away from petroleum-derived colors.

How to spot Red 40 on an ingredient label

To avoid Red 40, consumers must carefully read the ingredient lists on packaged foods, personal care items, and over-the-counter drugs. Because regulatory agencies in different regions require different naming conventions, Red 40 can appear under several aliases.

Always check your ingredient labels for the following names:

• FD&C Red No. 40: commonly used in U.S. food and cosmetics labels
• Allura Red AC: the internationally recognized chemical name, common in Europe and Canada
• Red 40 Lake: a water-insoluble form used primarily in fat-based foods, pharmaceuticals, and cosmetics
• CI 16035: the Color Index number typically found on personal care products and cosmetics
• E129: the European food additive code

In addition to checking for these chemical terms, look for warning statements on international packaging regarding attention and activity in children. Checking labels diligently is the most reliable way to protect sensitive individuals from accidental exposure.

What are the best natural alternatives to Red 40?

As food manufacturers shift away from synthetic azo dyes, a variety of safe, plant-derived alternatives are taking their place. These natural colorants provide vibrant red, pink, and orange hues without petroleum processing or risk to gut barrier health.

Excellent natural alternatives include:

• Beet Juice Concentrate: Yields a deep red-pink hue and is rich in antioxidants called betalains.
• Paprika Extract: Offers a warm, reddish-orange color along with natural carotenoids.
• Anthocyanins: Extracted from red cabbage, purple sweet potatoes, or grape skins, these compounds provide a versatile spectrum of reds and purples.
• Pomegranate and Cranberry Extracts: Provide subtle red hues alongside beneficial phytonutrients.

Choosing products colored with these plant-based ingredients allows you to enjoy visually appealing foods while protecting your digestive and cognitive health.