Carrageenan

Last reviewed October 18, 2026 · Evidence strength: Limited · How we grade evidence

In plain words: Carrageenan is a seaweed-based thickener. It isn't poisonous: safety agencies find no toxic effects at the amounts in food, though Europe has asked for more data. Small human studies suggest it may irritate the gut or nudge inflammation in some people, especially people with colitis or extra weight. If anyone in your family has IBD or gut trouble, it's a reasonable ingredient to limit.

Also listed on labels as: Carrageenan, Irish moss extract, E407, Processed eucheuma seaweed (E407a)

What is it, and why is it in food?

Carrageenan comes from red seaweed. It thickens and stabilizes foods so they don't separate: ice cream, chocolate milk, plant-based milks and creamers, cottage cheese, deli meats and some infant formulas. Degraded carrageenan (poligeenan), which is used in lab studies to cause gut inflammation, is a different substance and isn't allowed in food.

What does the science say?

• Ulcerative colitis: In a tiny trial (12 people in remission), 3 of those who took carrageenan capsules relapsed, versus none on placebo.¹
• Gut and insulin: In a 2024 double-blind crossover trial in 20 young men, carrageenan made the gut lining more permeable ("leaky"). In the overweight men only, it also lowered insulin sensitivity and raised inflammation markers.²
• Population studies: In the French NutriNet-Santé cohort, higher carrageenan intake was linked with slightly higher type 2 diabetes risk and with breast cancer. These are links, not proof, and need confirming.³⁴
• Toxicity: Animal studies found no toxic effects even at very high doses (up to 7,500 mg per kg of body weight a day in rats).⁵ A 2014 safety review by a toxicology consultant reached a similar conclusion.⁶

What do regulators say?

• EFSA (2018) found no safety concern at current uses but made its safe daily limit temporary (75 mg per kg of body weight) because of data gaps, and asked for better studies.⁵
• FDA permits food-grade carrageenan. Degraded carrageenan (poligeenan) isn't authorized as a food additive.

Who should be careful?

• People with ulcerative colitis, Crohn's disease or IBS: it's reasonable to try avoiding carrageenan and see if symptoms improve. Tell your GI doctor.
• People with insulin resistance or extra weight, based on the 2024 trial.
• Healthy kids and adults don't need to worry about occasional amounts.

How common is it in US foods?

In our check of USDA's Branded Foods database, 24,136 of 439,966 US packaged foods with an ingredient list name carrageenan (about 5.5%, or roughly 1 in 18).⁷ It shows up most often in: ice cream & frozen yogurt (7,634); cakes, cupcakes, snack cakes (1,243); milk (1,199); cheese (1,037); pepperoni, salami & cold cuts (690). About a third are ice cream and frozen desserts. It also shows up in snack cakes, flavored milks and cheese. These are label records companies sent to USDA, mostly in 2021 to 2023, so some products have changed since. Counts come from a text match of ingredient lists and are approximate.

Swaps and tips for families

• Many plant milks and creamers now come carrageenan-free; scan and compare.
• Choose ice creams with short ingredient lists (cream, milk, sugar, eggs).
• For deli meat, freshly roasted turkey or chicken works well in lunches.

Beyond the plate: related non-food exposures

Carrageenan is common in liquid supplements, protein shakes, plant milks and some toothpastes.

Frequently asked questions

Is carrageenan toxic?

No. Animal studies found no toxic effects even at very high doses. The concern is a possible gut irritation effect in some people, not poisoning.

Is carrageenan bad for your gut?

It might be for some people. A 2024 trial found it made the gut lining more permeable, and a tiny trial linked it to colitis relapses. Healthy people likely tolerate normal amounts.

Is carrageenan banned in Europe?

No. It's allowed as E407, but Europe's safe limit is temporary while it waits for better data.

Is carrageenan the same as degraded carrageenan?

No. Degraded carrageenan (poligeenan) is a different, broken-down form used in lab studies, and it isn't allowed in food.

Related guides

• Carboxymethylcellulose (Cellulose Gum)
• Polysorbate 80
• Guar Gum
• Emulsifiers and thickeners

Sources

Every source below was checked against PubMed, the publisher or the official page by our research team in October 2026.

1. A randomized trial of the effects of the no-carrageenan diet on ulcerative colitis disease activity. Nutrition and healthy aging, 2017. PubMed 28447072 · doi:10.3233/NHA-170023
2. Carrageenan and insulin resistance in humans: a randomised double-blind cross-over trial. BMC Med, 2024. PubMed 39593091 · doi:10.1186/s12916-024-03771-8
3. Food additive emulsifiers and the risk of type 2 diabetes: NutriNet-Santé. Lancet Diabetes Endocrinol, 2024. PubMed 38663950 · doi:10.1016/S2213-8587(24)00086-X
4. Food additive emulsifiers and cancer risk: Results from the French prospective NutriNet-Santé cohort. PLoS medicine, 2024. PubMed 38349899 · doi:10.1371/journal.pmed.1004338
5. Re-evaluation of carrageenan (E 407) and processed Eucheuma seaweed (E 407a) as food additives. EFSA journal. European Food Safety Authority, 2018. PubMed 32625873 · doi:10.2903/j.efsa.2018.5238
6. Food additive carrageenan: Part II: A critical review of carrageenan in vivo safety studies. Critical reviews in toxicology, 2014. PubMed 24467586 · doi:10.3109/10408444.2013.861798
7. FoodData Central, Branded Foods dataset (release 2026-04-30). U.S. Department of Agriculture, Agricultural Research Service, 2026. Link

This guide is for general education. It is not medical advice and does not replace advice from your doctor, pediatrician, allergist or registered dietitian. If you think you or your child reacted to a food, talk to a health professional. Research changes; we review these pages when new evidence or rules come out. Last reviewed October 18, 2026. Spotted an error? Email [email protected].