FD&C Red 40: What It Is, Where It’s Used, & Health Effects

Artificial dyes are used in a variety of edible products, medications, and personal care items.

Controversy over the possible negative health effects of synthetic dyes has abounded since their introduction to the food supply in the mid-1800s (3).

Over the years, many new dyes have been added to the list of FDA-approved substances, and some have been removed after adverse health effects were reported (3).

This article will review the history of Red Number 40, including what it is, where it is commonly used, possible health effects, and natural alternatives.

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What is FD&C Red #40?

FD&C Red 40 is a synthetic dye used in food, drugs, and cosmetics (including those used in the eye area), in both the United States and Europe (1).

It was approved for use in the United States in 1971 and has become the most commonly used dye in our food supply (2, 3).

What is Red 40 made of?

Red No. 40 is a dark red, water-soluble, azo dye (4).

A dye is considered an “azo” if it has the bonds C-N=N-C.

Most azo dyes are made from petroleum, a naturally occurring liquid found beneath Earth’s surface that is used to produce fuel (gasoline, diesel, etc.) (56).

Other names for FD&C Red #40:

FD&C Red No. 40 is the most common name used in the United States. (FD&C stands for Food, Drug, & Cosmetics – meaning the dye is approved by the FDA for use in those 3 types of products.)

It can also go by the following names (7):

  • Allura Red
  • Allura Red AC
  • E129 (Europe)
  • FD&C Red 40
  • FD&C Red No. 40
  • INS 129
  • Red 40
  • Red No. 40
  • C. I. 16035
  • C.I. Food Red 17

You may also see “FD&C Red No. 40 Lake” listed on some products.

A lake is made by combining a dye with a metallic salt, such as aluminum hydroxide, which makes the dye insoluble (8).

Lake dyes are generally used in products that don’t contain enough water for the dye to dissolve (pills, cosmetics, etc.).

Is Red 40 vegan?

Yes! Red 40 is made from petroleum and does not contain any animal products (5).

However, Red 40 is frequently tested on animals, so people who use only cruelty-free products will want to avoid it.

What foods commonly contain Red Number 40?

It is the most commonly used dye in the United States, especially in food products marketed to children (9).

This dye is required to be listed on the ingredients label of any product in which it is used, so reading labels is the best way to identify products that contain it.

However, this is not foolproof, since the FDA routinely fines companies for not declaring the use of dyes in their products.

Here are some examples of popular products that currently contain Red #40:

Baked goods





Dairy Products

Snack Foods

Bottled Items



One study of over 3000 children in Kuwait found that beverages made up 42% of daily Red #40 intake, while chips and puffed snacks made up 29% (10).

What medications commonly contain FD&C Red #40?

You can look up the ingredients in any medication on the website RXList.com.

Be sure to look up the exact dosage and type you take, since they can use different colors.

Some common medications that contain red #40 include:

In addition, some E-cigarettes can contain Red #40.

What cosmetics commonly contain FD&C Red #40?

Common Sources of FD&C Red 40 - Functional Nutrition Answers

How is FD&C Red #40 absorbed and metabolized?

After Red 40 is consumed, some of it can be absorbed into the bloodstream, broken down by enzymes in the liver, and excreted in the urine (11).

However, most of it (76-95%) remains in the intestines where it can be metabolized by intestinal bacteria and excreted in the stool (1112).

Is there a maximum amount of FD&C Red #40 allowed per day?

The FDA has declared an acceptable daily intake level (ADI) of no more than 7 mg/kg body weight per day.

Foods, drugs, and cosmetic labels are not required to list how much of the dye they use in their products, but various countries have legal limits.

In the EU (European Union), foods can contain up to 25 to 500 mg/kg (varies by type), alcoholic beverages can contain up to 200 mg/L, and nonalcoholic beverages can contain up to 100 mg/L (4).

Interestingly, it appears that many children exceed the ADI by consuming beverages and snacks that contain this dye (10).

Can people have a Red 40 allergy?

Sure! Adverse reactions (allergic or hypersensitivity reactions) have been reported.

They are more common in people predisposed to allergic diseases (2 – 7% affected, vs <0.25% in the general population) (13).

Symptoms are usually mild and may include hives, itching, runny nose, and vomiting. In rare cases, anaphylaxis has been reported (1314).

There is also some evidence that artificial food dyes may cause hyperactivity in about 30% of children with ADHD, but more research is needed (15).

Is Red 40 bad for you?

Genotoxicity and mutagenicity

FD&C Red #40 has been studied to determine whether it can damage DNA and cause mutations that may lead to cancer.

It has not been found to cause mutations in a variety of in vitro studies (161718).

Two mice studies found that doses of just 10 mg/kg body weight (which is close to the ADI of 7 mg/kg body weight) caused DNA damage in the colon within hours of consuming it (1920).

However, these results were not replicated in rats (20).

When mice were injected with red #40 into the peritoneal cavity, it did not appear to be genotoxic (21).

Impact on growth rates

Two studies found that mice and rats had slightly slower growth rates when they received very high doses of the dye (2595 mg per kg body weight per day or up to 10% of the diet) (22, 23).

Of course, mice are not the same as humans, so more research is needed.

Drug absorption

Large doses (25 mg/kg body weight) of Red #40 can interfere with the absorption of some drug compounds in mice, but in humans, the microbiome can metabolize the dye into compounds that no longer interfere with the OATP2B1 transport (24).

Teeth stains

Concern about teeth staining from consuming artificial dyes after teeth whitening has turned out to be unfounded (25).

What are some natural alternatives to Red #40?

Anthocyanins, natural pigments occurring in flowers, fruits, and vegetables, are most often used to replace FD&C #40 in food products.

However, they tend to be less stable and more prone to degradation and color changes than artificial dyes (2627 ).

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3 thoughts on “FD&C Red 40: What It Is, Where It’s Used, & Health Effects”

  1. I just bought some extra strength acetaminophen tabs that contain this red dye. I called the company to ask about safety and spoke to some idiot who knows nothing. I decided to just wash the dye off the tablet before I swallowed it.

  2. My daughter and I are trying to figure out

    How do I go about finding out if Red 40 really affects my Grandson s autism. He does not take anything except melatonin. If he doesn’t take it, he crawls all over the place. He is only 6 years old. We separate all his candy. From Halloween, Christmas, easter etc. Have you ever heard of such of thing. The school is on board with this. Please help !

  3. It really pisses me off that companies are banned from using harmful chemicals in some countries but not in the United States! It’s yet more proof that our government values money over our health!

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