Algas, Algue Rouge Marine, Carageenan Gum, Carastay, Carrageen, Carrageenin, Carragenano, Carragenina, Carragheenan, Carraghénane, Carraghénine, Chondrus Extract, Danish Agar, Eucheuma Spinosum Gum, Extrait de Mousse d'Irlande, Galgarine, Iota-Carrageenan, Irish Moss, Irish Moss Algae, Irish Moss Extract, Irish Moss Gelose, Kappa-Carrageenan, Lambda-Carrageenan, Marine Colloids, Mousse d'Irlande, Norsk Gelatin, PES, Processed Eucheuma Seaweed, Red Marine Algae, Red Seaweed Extract, Vegetable Gelatin.


Overview Information

Carrageenan is made from parts of various red algae or seaweeds. It is commonly used to thicken foods. It is also sometimes used as medicine.

Carrageenan is used for coughs, colds, and other conditions, but there is no good scientific evidence to support these uses.

How does it work?

Carrageenan contains chemicals that may decrease stomach and intestinal secretions. Large amounts of carrageenan seem to pull water into the intestine, and this may explain why it is tried as a laxative. Carrageenan also might decrease pain and swelling (inflammation).


Uses & Effectiveness?

Insufficient Evidence for

  • Common cold. Most research shows that spraying saline with iota-carrageenan into the nose does not reduce common cold symptoms when compared with using a regular saline spray. But not all research agrees.
  • Cough.
  • Bronchitis.
  • Other conditions.
More evidence is needed to rate the effectiveness of carrageenan for these uses.

Side Effects

Side Effects & Safety

When taken by mouth: Carrageenan is LIKELY SAFE for most people when taken by mouth in food amounts. There is also a chemically altered form of carrageenan that is available in France to treat peptic ulcers. This form is POSSIBLY UNSAFE because animal studies have shown that it might cause cancer. But this risk hasn't been shown in humans.

When sprayed into the nose: Carrageenan is POSSIBLY SAFE for most people when sprayed into the nose, short-term. No side effects have been reported in clinical research.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Carrageenan is LIKELY SAFE in amounts found in food, but there's not enough information to know if it's safe in the larger amounts that are used as medicine. It's best to stay on the safe side and stick to food amounts.

Bleeding disorders: Carrageenan might slow blood clotting and increase bleeding. In theory, carrageenan might make bleeding disorders worse.

Surgery: Carrageenan might slow blood clotting in some people. In theory, carrageenan might increase the risk for bleeding and interfere with blood pressure control during surgical procedures. Stop using carrageenan at least 2 weeks before a scheduled surgery.



Moderate Interaction

Be cautious with this combination

  • Medications for high blood pressure (Antihypertensive drugs) interacts with CARRAGEENAN

    Carrageenan seems to decrease blood pressure. Taking carrageenan along with medications for high blood pressure might cause your blood pressure to go too low.
    Some medications for high blood pressure include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), Amlodipine (Norvasc), hydrochlorothiazide (HydroDiuril), furosemide (Lasix), and many others.

  • Medications taken by mouth (Oral drugs) interacts with CARRAGEENAN

    Carrageenan is a thick gel. Carrageenan can stick to medications in the stomach and intestines. Taking carrageenan at the same time as medications that you take by mouth can decrease how much medication your body absorbs, and decrease the effectiveness of your medication. To prevent this interaction, take carrageenan at least one hour after medications you take by mouth.

  • Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs) interacts with CARRAGEENAN

    Carrageenan might slow blood clotting. Taking carrageenan along with medications that also slow clotting might increase the chances of bruising and bleeding.
    Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others.



The appropriate dose of carrageenan depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for carrageenan. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

View References


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  • Carlucci, M. J., Scolaro, L. A., and Damonte, E. B. Inhibitory action of natural carrageenans on Herpes simplex virus infection of mouse astrocytes. Chemotherapy 1999;45(6):429-436. View abstract.
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