Health Benefits of Sea Moss

Medically Reviewed by Jabeen Begum, MD on November 01, 2023
6 min read

Sea moss, also known as Irish moss or red seaweed, is a type of seaweed that grows year-round in tidepools and inlets. It's found along the coastlines of Europe, North America, and the British Isles.

Sea moss is commonly harvested to extract carrageenan, a jelly-like substance often used by the food industry as a thickener. You'll find it in ice cream, nondairy milk, cottage cheese, jelly, and even toothpaste, shoe polish, and infant formula. Carrageenan is also used to cure leather.

Sea moss is tufted and has thin fanlike fronds. It comes in many colors, from greenish-yellow to dark purple, and is alleged to have many health benefits, though most have not been studied scientifically. The algae can be made into a drink by boiling and adding milk and honey. In some countries, it's considered to be an aphrodisiac for men.

Sea moss gel

Sea moss gel is a natural, nutrient-rich product derived from sea moss. Some people mix it with water to make a puree that they take by the spoonful or add to a smoothie. The gel has a texture similar to aloe vera, and it tastes like clams or oysters. Like all seaweeds, sea moss is high in minerals such as iodine, potassium, calcium, as well as vitamins and protein.

Ever since Kim Kardashian posted about drinking a sea moss smoothie, the healthy eating community has been bursting with information about this superfood, claiming that sea moss can help with everything from your skin to your immune system. But how many of the benefits of sea moss are based on science and how many are just hearsay? 

The truth is that while people have eaten this algae for years, scientists are only now beginning to research its medical benefits. Here’s what we know so far. 

May prevent Parkinson’s disease

Parkinson’s disease is the second most common degenerative disease in older adults. It causes tremors, stiffness, and slowness of movement, and there is no cure. But early research shows that sea moss may be able to slow the worsening of the disease.

In a study done with worms, extract from sea moss was shown to reduce stiffness and slowness of movement. This could mean promising things for people with Parkinson’s. But more research is needed to see if sea moss has the same effect on humans that it has on worms. 

May improve the immune system

Early studies suggest that sea moss can boost the immune system and may even protect the body from contracting salmonella. 

One study showed that sea moss can stop the growth of S. enteritidis, the bacteria that causes salmonella in humans. But this is a very early study, and the effect has not been reproduced in animals or humans. More research is needed to determine whether sea moss could help prevent or treat salmonella in humans. 

May support thyroid health

Sea moss is full of iodine, so it should help people with hypothyroidism, a condition where your body doesn't make enough thyroid hormones, which regulate your body's metabolism. Metabolism is how the food you take into your body is transformed into energy and also regulates processes like your heart rate and your breathing. But talk to your doctor before deciding to use sea moss to manage your hypothyroidism, especially if you're already taking medication for it.

One of the reasons sea moss has been touted as a superfood recently is that it’s a vegan, gluten-free source of many nutrients. Some of the nutrients in sea moss are:

  • Vitamin B2
  • Calcium
  • Iodine
  • Potassium
  • Sodium
  • Magnesium
  • Zinc

Nutrients per serving

2 tablespoons of sea moss contain: 

  • Calories: 5
  • Fat: 0 grams
  • Cholesterol: 0 milligrams
  • Sodium: 7 milligrams
  • Carbohydrates: 1 gram
  • Fiber: 0 grams
  • Sugar: 0 grams
  • Protein: 0 grams


Although Irish moss offers many health benefits and can improve your body’s overall function, some studies have shown that carrageenan may have negative effects.

Under certain circumstances, carrageenan can be converted into “degraded carrageenan,” or poligeenan, which is known to be toxic and may cause several health problems. There is no scientific evidence to show that your body can convert carrageenan to poligeenan. But some seaweed can contain poligeenan naturally.

May cause intestinal inflammation

Poligeenan can lead to inflammation of the intestines, causing problems with your body's ability to absorb nutrition. This can also lead to discomfort and bloating over time. It may also be linked with colitis and symptoms of Crohn’s disease.

May cause stomach ulcers

In large amounts, poligeenan has also been shown to cause stomach lesions and ulcers in animal studies. More poligeenan is generally connected to larger ulcers. 

May lead to stomach and bowel cancer

Finally, poligeenan has also been linked to polyps that may become cancerous. Poligeenan appears to cause problems in the digestive tract that lead to cell mutations commonly found in cancers, particularly in cases where ulcers are found. 

It’s important to note that carrageenan has none of these effects. The FDA has determined that carrageenan is safe to use as a food additive, and the human body cannot produce conditions to convert carrageenan to poligeenan.

Eating too much sea moss can also cause stomach upset, including nausea, vomiting, and diarrhea. 

Can cause thyroid problems

High levels of iodine found in sea moss can cause thyroid issues and even cancer. Having too much iodine in your diet can lead to a goiter, or an enlarged thyroid gland, which may require surgery. In general, experts advise against taking iodine supplements, as it's unclear how they will react with your thyroid.

Risk of heavy metal consumption

Seaweed that grows in waters near industrial pollution or raw sewage may contain toxic metals like arsenic, mercury, and lead, which can be dangerous to consume. The levels of these metals is generally low, but it's another reason to be careful about how much sea moss you take in.

Finally, Irish moss may have blood-thinning properties, so people taking blood-thinning medication should avoid it. Pregnant and breastfeeding people should also avoid sea moss because there is not enough research on its effects on these populations.

Sea moss supplements are sold in many formulas, including gels, powders, capsules, and gummies. The formula doesn't matter, as long as you don't take too much of it. Although raw sea moss has a "fishy" taste, the supplements are usually tasteless. Before adding sea moss to your diet, talk to a health care professional.

Portion sizes

A serving of sea moss is just 2 tablespoons, so you don't need much to get health benefits.


Many brands have begun selling sea moss pills and powders. But you can prepare sea moss yourself to use in recipes or to take as a health supplement. 

First, wash the sea moss and then soak it in cold water for a full day, changing the water frequently and removing any dirt you see. You can leave this on your kitchen counter to soak, as you don't need to refrigerate it.

You’ll know your sea moss is ready to use when it's doubled in size and become white and jelly-like. 

Once it’s ready, put the sea moss, along with some water, into a blender and blend until smooth. Start with 1 cup of water and add more if the mixture is too thick. Then refrigerate for at least 2 hours, which will thicken it some more.

Once you have your prepared sea moss, you can store it in the fridge for up to 2 weeks and use it in recipes. For instance:

  • Smoothies
  • Soups
  • Stews
  • Baked goods

You can also make sea moss gel from sea moss powder by blending 1/4 cup of powder with 2 cups of hot (not boiling) water in your blender. Cool the mixture and store it in your refrigerator.