Red Dye 40: What It Is, Where It Turns Up, and What the Science Actually Says

KEY TAKEAWAYS

•     Red Dye 40, also called Allura Red AC or E129, is the most widely used food colouring in the world

•     It is made synthetically from petroleum derived chemicals, not from insects. That is carmine, a different colouring

•     Allergic type reactions are real but uncommon

•     The link with hyperactivity in children is contested. The EU requires a warning label, the US does not

•     In April 2025, US health authorities announced a voluntary phase out of Red 40 and five other synthetic dyes. It is not formally banned

•     Several US states have passed their own restrictions, starting with school food

•     It adds only colour, so there is no nutritional cost to avoiding it

Ever wondered why a cherry flavoured ice lolly turns your tongue bright red, while a real cherry barely leaves a trace? The answer, very often, is Red Dye 40.

Red Dye 40, also known as Allura Red AC, FD&C Red No. 40, or E129 in Europe, is one of the most widely used food colourings in the world. It gives sweets, drinks, cereals and snacks their bright red and orange shades. It is also one of the most debated food additives, and in the United States its future is now uncertain.

The debate is genuinely unsettled in places, which is why you can find confident claims in both directions. This guide separates what is established from what is not, explains the latest regulatory changes, and shows how to identify and reduce it if you choose to.

What Red Dye 40 is made from

Despite a persistent myth, Red Dye 40 is not made from insects. That is carmine, also called cochineal or E120, a natural red colouring made from crushed cochineal insects. Red Dye 40 is a synthetic azo dye made from petroleum derived chemicals. That description sounds alarming, but it describes the chemical starting material. Many approved additives and medicines are made the same way, and the finished dye is purified and tested before use.

In the United States, each batch of Red 40 must be certified by the FDA to meet purity standards before it can be used in food.

Where you will find it

Red 40 appears in far more than sweets. It turns up in orange, purple and brown foods as well as red ones, because it is often blended with other colourings.

Category	Common examples
Drinks	Soft drinks, sports drinks, energy drinks, flavoured waters, powdered drink mixes
Sweets	Gummies, jelly sweets, hard candies, chewing gum, frosting
Breakfast foods	Brightly coloured cereals, pastries, flavoured oatmeal
Dairy	Flavoured yoghurts, ice cream, flavoured milk
Snacks	Flavoured chips, cheese puffs, snack cakes
Baked goods	Red velvet cake, cake mixes, cookies
Condiments	Some barbecue sauces, salad dressings, pickles
Medicines	Children's syrups, chewable tablets, coated tablets
Cosmetics	Lipstick, blush and other products

How to identify it on a label

Red 40 can appear on ingredient lists under several names:

•     Red 40 or Red 40 Lake

•     FD&C Red No. 40

•     Allura Red or Allura Red AC

•     E129 in Europe and other countries using E numbers

•     INS 129 in countries using the International Numbering System

A lake is a version of the dye bound to a mineral so that it does not dissolve in water, used in coated tablets, fat based foods and cosmetics.

How much is considered safe?

International experts have set an acceptable daily intake of 7 mg per kilogram of body weight. For an adult weighing 68 kg, that works out to about 476 mg a day. For a child weighing 30 kg, it is around 210 mg.

Most people consume far less than this. The concern is mainly about children who eat a lot of brightly coloured sweets, drinks and snacks every day, and about people who are individually sensitive, since reactions can occur well below the acceptable intake.

A useful label tip: ingredients are listed in order of weight, from most to least. A product that lists Red 40 near the end generally contains less of it than one that lists it near the top.

What the evidence supports

Allergic and sensitivity reactions

A small number of people experience hives, itching, swelling or worsening asthma after consuming Red 40. These reactions are documented and accepted, though uncommon. People sensitive to one azo dye are sometimes sensitive to others.

Hyperactivity in children

This is the most contested area. The frequently cited 2007 Southampton study, published in The Lancet, found that mixtures of artificial colourings with the preservative sodium benzoate were associated with increased hyperactivity in some children from the general population, not only those with ADHD.

Following that research, the European Union required foods containing six colourings, including Allura Red, to carry a label stating that they may have an adverse effect on activity and attention in children. Many manufacturers selling in Europe reformulated rather than use the warning.

In 2021, a report by California's Office of Environmental Health Hazard Assessment reviewed the evidence and concluded that synthetic food dyes can cause or worsen behavioural problems in some children.

Other regulators have weighed the same evidence differently. International expert bodies have set an acceptable daily intake of 7 mg per kilogram of body weight for Allura Red, and have maintained that it is safe at normal intakes. These differences largely reflect judgements about how to handle inconsistent findings, not secret data on either side.

Emerging research

Some animal studies have suggested Red 40 may affect gut inflammation or the gut lining at high exposure. These findings are preliminary and have not been confirmed in humans, but they are part of why interest in the dye has grown.

What is not established

•     That it causes ADHD. Some children appear sensitive and show behavioural changes, which is different from causing the condition

•     That it causes cancer at dietary levels. Reviews have not found convincing evidence of this in humans

•     That it harms most people. The majority consume it with no identifiable effect

The latest regulatory changes

The regulatory picture has changed considerably since 2025, particularly in the United States.

Development	What it means
January 2025: FDA revokes Red No. 3	A different dye, Red 3, is banned in US food, with manufacturers given until January 2027 to reformulate
April 2025: US phase out plan announced	Health authorities asked manufacturers to voluntarily remove Red 40 and five other synthetic dyes. It is not a formal ban
2025 onward: State laws	West Virginia, California and Utah passed restrictions, starting with food served in schools
2026: New natural colours approved	The FDA has been approving additional natural colour additives to help manufacturers switch
European Union	Allura Red remains permitted with a warning label on foods

As of 2026, Red 40 is not banned federally in the United States. It remains legally authorised while the voluntary phase out and state level laws progress. Timelines have been described differently in different official statements, so check current guidance if this affects you. Several large food companies have announced they will remove synthetic dyes from their products.

Rules differ between countries. If you live outside the US and EU, check your national food regulator for which synthetic colours are permitted and any limits on their use.

How to reduce your intake

1.   Read ingredient lists, since colour is not a reliable guide

2.   Choose products coloured with natural sources, such as beetroot, paprika, turmeric, annatto, spirulina or fruit and vegetable juices

3.   Cut back on ultra processed foods generally, which removes most sources at once

4.   Check medicines and supplements, particularly children's syrups and chewables. Dye free versions are often available, so ask a pharmacist

5.   Be wary of no artificial colours claims and still check the label

6.   If you suspect sensitivity in a child, a short elimination and reintroduction trial can help. Do this with your doctor rather than removing many foods at once

One situation where your doctor will ask you to avoid it

If you are preparing for a colonoscopy, you will usually be told to avoid red and purple coloured foods and drinks beforehand. The reason is not safety. Red colouring can look like blood in the bowel and make the examination harder to interpret.

A sensible way to think about it

Red Dye 40 has one purpose, which is appearance. It adds no nutritional value, so there is no cost to avoiding it if you prefer to. At the same time, there is no strong evidence that it harms most people at normal intakes, so it does not warrant panic.

The more useful point is what it signals. Foods containing it are overwhelmingly ultra processed, high in sugar and low in fiber. Improving that broader pattern has much stronger evidence behind it for long term health than removing the dye alone.

Myths versus facts

Myth	Fact
Red Dye 40 is made from insects	That is carmine. Red 40 is synthetic
It is banned in Europe	It is permitted in the EU, with a warning label
It is only in red foods	It appears in orange, purple, brown and even some pickled foods
It causes ADHD	Some children may be sensitive, but it has not been shown to cause ADHD
The US banned it in 2025	The US announced a voluntary phase out. It was Red 3 that was formally banned

Frequently asked questions

Is Red Dye 40 banned in Europe? No. It is permitted, but foods containing it must carry a warning about possible effects on children's attention.

Is Red Dye 40 banned in the US? Not federally as of 2026. There is a voluntary phase out and several state laws.

Is Red 40 the same as carmine? No. Carmine comes from insects. Red 40 is synthetic.

Is Red 40 the same as Red 3? No. Red 3 is a different dye, which the FDA formally banned in food in January 2025.

Should I remove it from my child's diet? If you suspect a reaction, a supervised trial removal is reasonable. There is no universal recommendation to avoid it.

Is Red 40 vegan? It is not made from animals, which is why some vegans prefer it to carmine, though some avoid it because of historical animal testing.

DISCLAIMER

This article is for general information only and is not a substitute for professional medical advice, diagnosis or treatment. Please consult a qualified healthcare professional before making decisions about your health.