Irish Moss is essentially a type of seaweed that can grow up to 6 inches long in parts of the North Atlantic. It is harvested to make carrageenan, a thickening agent, and has been used as a traditional herbal remedy in Ireland. What is particularly unique about it is that it is known to contain high levels of iodine. It is also known to contain calcium, sulfur, potassium and vitamin E. Some people use is for its Vitamin K content for their skin. Used in teas, tinctures or taken as an extract. Note: those with seafood or shellfish allergies should beware of potential severe reactions.