Irish Moss Side Effects

Irish moss is known scientifically as Chondrus crispus. It is an evergreen ground cover that is also frequently called carrageen moss. Irish moss flourishes in rocky soil types. A type of seaweed, it is not actually related to moss, although it has a similar appearance. Irish moss blooms small white flowers. It has various medicinal uses, particularly for soothing coughing and reducing cholesterol levels. There are several side effects that are occasionally associated with use of Irish moss.

Irish moss appears off the Atlantic Coast of Ireland.

Blood Thinning

Irish moss functions as a thinner. As a result, individuals that are taking anticoagulant medications (blood thinners) should abstain from using Irish moss in any form. Anticoagulant medicines are medications that decrease the ability of the blood to formulate clots.


People that use Irish moss while also taking antihypertensives may experience some negative side effects. Antihypertensive medication is used to treat hypertension, which is also known as high blood pressure. Side effects that may occur include feeling lightheaded, dizziness and syncope (a brief loss of posture and consciousness).

Other Possible Side Effects

Other side effects that occasionally occur with the use of Irish moss are diarrhea, abdominal cramping, bleeding and hypotension (low blood pressure).


Females that are either nursing or pregnant should not use Irish moss, as its effects are unknown. Infants should not be given Irish moss, as it is capable of suppressing the immune system. Individuals that have low blood pressure or any underlying bleeding conditions must speak with their doctors before using Irish moss. The plant is also contraindicated for people that have or have had peptic ulcer disease in the past.