Irish moss is obtained from the dried thallus of Chondrus crisp us. It’s a form of seaweed containing polysaccharides, vitamins, minerals, and iodine. The extract is known as carrageenan, a starch-like substance. This extract can be further differentiated into two types, k-carrageenan and I-carrageenan. The former type is the gelling fraction; the latter form is the non-gelling component.
Irish moss has expectorant, demulcent, anti-inflammatory, anticoagulant, antihypertensive, immunosuppressive, and antidiarrheal properties. It also interferes with the absorption of food, and may reduce serum cholesterol and possess antiviral activity. Irish moss is available as dried jellied fruit, jellies, puddings, raw leaves, and teas, in products such as Coreine, Gelcarin, Hydrogel, Seaspen, and Viscarin.
Irish moss is used to soothe irritating coughs that result from various respiratory infections, and to produce bulky stools in patients with chronic diarrhea. Because of its demulcent properties, Irish moss is also used to treat gastritis and peptic ulcer disease. Because it contains ammonium, calcium, magnesium, potassium and sodium esters of galactose and 3-G-anhydrogalactose copolymers it’s also used as a nutritional supplement to facilitate recuperation in those with debilitating diseases. Irish moss can also be found as an ingredient in weight-loss products.
Irish moss is used as a skin softener in commercial cosmetic products and lotions. It’s used topically to treat anorectal symptoms. In manufacturing, Irish moss can be used as a binder, emulsifier, thickener, and as a stabilizer in drugs, foods, and toothpaste.
A tea is prepared by boiling 1 oz (28 g) of dried plant in 1 to 2 pints of water for 10 to 15 minutes, and then straining. Dosage is 1 cup two to three times a day. Lemon, honey, ginger, or cinnamon may be added to enhance the flavor.
Irish moss may cause bleeding, hypotension, cramping, diarrhea, and infection. There is an increased risk of bleeding when Irish moss is used concomitantly with anticoagulants. Irish moss may potentiate the hypotensive effects of antihypertensives. It may decrease the absorption of drugs. Advise patient to separate administration times by at least 2 hours.
Pregnant or breast-feeding patients should avoid use. Infants shouldn’t be given Irish moss because it may suppress the immune system. Patients with underlying bleeding disorders or hypotension should use Irish moss with caution.
Monitor blood pressure regularly during the course of therapy with Irish moss. Patient should also be monitored for signs and symptoms of bleeding.
In patient receiving warfarin, closely monitor prothrombin time and International Normalized Ratio.
Tell patient to avoid taking Irish moss within 2 hours of other drugs.
If patient is taking Irish moss with an antihypertensive, instruct him to notify his health care provider if dizziness, light-headedness, or syncope occurs.
If patient is using Irish moss to treat diarrhea, advise him to consult his health care provider if the diarrhea persists for longer than 3 to 4 days.
Caution patient to keep Irish moss out of the reach of children.
Avoid products that contain the degraded form of Irish moss because it has been known to cause lesions in animals.
Store in airtight containers in a cool place.
Tell patient to notify pharmacist of any herbal or dietary supplement that he is taking when obtaining a new prescription.
Advise patient to consult his health care provider before using an herbal preparation because a conventional treatment with proven efficacy may be available.
The concepts behind the use of Irish moss and the claims made regarding its effects haven’t yet been validated scientifically.