Is Red 40 Bad for You? What the Research Says
Red 40 is the most widely used artificial food dye in the US. Here's what scientists know about it, what regulators have done, and how to avoid it.
Red 40 — also known as Allura Red or FD&C Red No. 40 — is the most widely used artificial food dye in the United States. It's in candy, snacks, cereals, beverages, condiments, and even some medications.
If you've been hearing more about Red 40 lately, it's because the conversation around artificial food dyes is accelerating. The FDA banned a different dye (Red No. 3) in 2025, and multiple major food companies have announced plans to remove synthetic dyes from their products.
But Red 40 itself hasn't been banned. So what does the research actually say?
What Is Red 40?
Red 40 is a synthetic dye made from petroleum-derived aromatic hydrocarbons. It produces a bright red color and is used in thousands of food products sold in the United States. It was approved by the FDA in 1971 and is currently the most consumed artificial food dye by volume.
What the Research Shows
The research on Red 40 falls into a few categories:
Behavioral effects in children. The most-discussed area. A 2007 study from the University of Southampton, published in The Lancet, found that mixtures of artificial dyes (including a version of Red 40 used in the UK, along with Yellow 5 and Yellow 6) and sodium benzoate were associated with increased hyperactive behavior in some children. This study was influential enough to prompt the EU to require warning labels on foods containing certain artificial dyes.
The FDA reviewed the same evidence in 2011 and concluded that the data didn't establish a causal link between artificial dyes and hyperactivity in the general population. However, the FDA acknowledged that some children may be more sensitive to these effects.
Cancer research. Unlike Red No. 3 (which was banned due to evidence of thyroid tumors in rats), Red 40 has not been shown to cause cancer in animal studies at levels relevant to human consumption. The FDA considers it safe at current usage levels.
Gut health. More recent research has looked at potential effects of Allura Red on gut inflammation. A 2022 study from McMaster University found that chronic exposure to Allura Red in mice promoted gut inflammation. This is an area of active research that hasn't yet led to regulatory action.
Allergic reactions. Some individuals report sensitivity to Red 40, with symptoms including hives or other reactions. These cases are relatively rare.
How Different Countries Handle Red 40
The regulatory approach to Red 40 varies significantly by country:
- United States: Approved, no warning labels required. The FDA has encouraged the industry to phase it out voluntarily.
- European Union: Allowed, but foods containing it must carry a warning: "may have an adverse effect on activity and attention in children."
- Some EU manufacturers: Have voluntarily reformulated to avoid the warning label, meaning the European version of some products uses natural colors while the American version uses Red 40.
What the FDA Has Done Recently
The FDA hasn't banned Red 40, but the agency's position is evolving:
- In early 2025, the FDA banned Red No. 3 (a different dye) from food.
- The FDA has encouraged food companies to voluntarily move away from Red 40 and other synthetic dyes.
- In May 2025, the FDA approved three new natural color additives, giving manufacturers more alternatives.
- Multiple federal officials have pushed for broader synthetic dye reduction.
How to Avoid Red 40
If you want to avoid Red 40 in the food you buy:
- Read the ingredient list — Red 40 must be listed by name (also appears as "FD&C Red No. 40" or "Red 40 Lake")
- Look for natural color sources — fruit juice, vegetable juice, beet juice, paprika extract
- Don't rely on the front of the package — "natural flavors" doesn't mean "no artificial colors"
- Check your kids' snacks — Red 40 is especially common in candy, fruit snacks, and flavored drinks
- Look at brands that never used it — some brands were built dye-free from the start
The Bottom Line
Red 40 is legal and widely used in the US. The FDA considers it safe, though the agency has encouraged voluntary phase-out. The EU requires a warning label. The research on behavioral effects in children is real but debated. More recent research on gut health effects is ongoing.
Whether you choose to avoid Red 40 is a personal decision. But reading labels and knowing what's in your food is always a good starting point.
Want candy without Red 40? Shop USA Gummies — colored with fruit and vegetable extracts, never synthetic dyes.
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