Carrageenans are carbohydrates extracted from red seaweeds (such as Irish moss) and other sources. Irish moss grows around Ireland, as well as other coasts in Europe, and the Atlantic coasts of the United States. The Irish moss popularly used as a ground cover (Sagina subulata) is not the same as the Irish moss discussed in this monograph (Chondrus crispus).
Traditionally, carrageenan has been taken by mouth to soothe mucous membranes and as a laxative. Extracts of carrageenan have been used as food additives for hundreds of years. Carrageenan is currently used as a thickener and stabilizer for a wide range of foods, and is also used in personal hygiene products and drugs.
Carrageenan may lower lipid (cholesterol and triglyceride) and blood sugar levels. Although not well studied in humans, carrageenan-based gels may help prevent HIV transmission.

Related Terms

Algae, algal polysaccharides, anhydrogalactose, bejin behan (Breton), bejin gwenn (Breton), Betaphycus gelatinum, blomkalstang (Danish), botelho crespo (Portuguese), bouch (Breton), bouch farad youd (Breton), bouch gad (Breton), bouch gwenn (Breton), bouchounoù (Breton), cairgin (Gaelic), Callophyllis hombroniana, caragaen, caragahen, carragaheen, carrageen, carrageen moss, carrageenin, carrageentang (Danish), carragheen, carraghèen (French), carragheenan, Carraguard®, carraigín (Irish), carrapucho (Galician), Chondrus crispus, chondrus extract, Chondrus mamillosus, clúimhín cait (Irish), clúimhín caitcarraigín (Irish), cottonii, creba (Galician), curly gristle moss, curly moss, Dorset weed, Dragendorff, driesflik (Norwegian), Eucheuma cottonii, Eucheuma denticulatum, Eucheuma gelatinae, Eucheuma spp., Eucheuma spinosum, fiadháin (Irish), fjörugrös (Icelandic), folha de alface (Portuguese), folhina (Portuguese), fuco carageo, fuco crispo (Italian), Fucus crispus Linné, galactopyranose, galactose 4-sulphate, gelatintang (Norwegian), Gigartina acicularis, Gigartina canaliculata, Gigartina mamillosa, Gigartina pistillata, Gigartina skottsbergii, Gigartina stellata, Gigartinaceae (family), Gigartinales, goémon blanc (French), goémon fries (French), goémon rouge (French), hirakotoji (Japanese), Hypnea musciformis, Iers mos (Dutch), iota carrageenan, Iridaea ciliata, Iridaea ciliate, Iridaea laminaroides, Irish moss extract, Irländischer Perltang (German), Irländisches Moos (German), Irlandsk mos (Danish), jargod (Breton), jelly moss, Kallymeniaceae, kappa carrageenan, Kappaphycus alvarezii, Kappaphycus cottonii, Kappaphycus striatum, karragaheen (German), karrageentari (Faroese), karragen (Turkish), karragenalg (karragentang) (Swedish), Killeen, knorpeltang (German), krusflik (Norwegian), lambda carrageenan, lambda-carrageenan, Lamouroux, lichen, liken ruz (Breton), liquen (Spanish), marine algae, Mastocarpus mamillosus Kützing, Mastocarpus stellatus, mathair an diulisg (Gaelic), Mazzaella laminaroides, mousse d'irlande, mousse marine perlée (French), mousse perlée (French), mu carrageenan, muschio irlandese (Italian), musco d'lrlanda (Italian), musgo de Irlanda (Spanish), musgo gordo (Portuguese), musgo marino (Spanish), musgo marino perlado (Spanish), musgo perlado (Spanish), mwsog Iwerddon (Welsh), nu carrageenan, ouca riza (Galician), ougnachou-ru (Breton), pata de galiña (Galician), PC 213, PC-503, pearl moss, perimoos, perlmoos (German), petit goémon (French), Phacelocarpus peperocarpos, pigwiacis, pioka (Breton), poligeenan, red algae, red seaweed, Rhodophyceae, Rhodophyta, Rhodophytaa, Sarcothalia crispate, Sarcothalia crispate, sea moss, seamuisin, seaweed, seaweed extract, Sphaerococcus crispus Agardh, Sphaerococcus mamillosus Agardh, spinosum, stackhouse, teil piko (Breton), teles (Breton), theta carrageenan, tilez (Breton), tochaka (Japanese), tsunomata (Japanese), upsilon carrageenan, vaginal gel, white wrack.

evidence table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
HIV infection (prevention) (Grade: C)
Although not well studied in humans, carrageenan-based gels may prevent HIV transmission during sexual intercourse. Overall, studies suggest that carrageenan may be safe for use by males and females. High quality clinical study is needed to confirm these early results.
Lipid-lowering (cholesterol and triglycerides) (Grade: C)
In clinical study, a diet containing carrageenan-enriched foods lowered cholesterol and triglyceride levels. Further clinical trials are required before carrageenan can be recommended for its lipid-lowering effects.