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Reviewed by Christine Mikstas, RD, LD on January 27, 2023

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 those benefits are based on science and how many are just hearsay? 

The truth is that while people have eaten sea moss 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 found 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 progression of Parkinson’s 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 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.

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
• 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

Portion sizes

When it comes to using sea moss, remember that a little bit goes a long way. A serving of sea  

Evidence Based

This article is based on scientific evidence, written by experts and fact checked by experts.

Our team of licensed nutritionists and dietitians strive to be objective, unbiased, honest and to present both sides of the argument.

This article contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.

Sea moss, scientifically known as Chondrus crispus, is a type of algae or seaweed. It grows in waters along the rocky Atlantic coasts, primarily between North America and Europe (1).

It’s an edible sea plant similar to other seaweeds, algae, and other familiar leafy sea vegetables like kelp or dulse.

Sea moss grows in a number of colors, such as various shades of green, yellow, purple, red, brown, and black.

The most common varieties that grow in the warmer waters are generally red and often called Irish moss (2Trusted Source, 3Trusted Source).

SUMMARY

Sea moss is a spiny sea plant that’s similar to other seaweeds and algae. The most common variety in commercial products is red and often called Irish moss.

Red seaweeds like sea moss contain an array of vitamins and minerals. They’re naturally low in calories, fat, and sugar, and they contain a small amount of plant protein.

A 4-tablespoon (20-gram) serving of raw Irish sea moss provides the following (4Trusted Source

• Calories: 10
• Protein: 0.5      grams
• Total fat: 0      grams
• Total carbs: 3      grams
• Fiber: 0.5      grams
• Total sugar: 0      grams
• Calcium: 1%      of the Daily Value (DV)
• Iron: 10%      of the DV
• Magnesium: 7%      of the DV
• Phosphorus: 2%      of the DV
• Zinc: 4%      of the DV
• Copper: 3%      of the DV

Like other sea vegetables, sea moss is also a naturally good source of iodine, a micronutrient necessary for thyroid health (5Trusted Source

Many people use sea moss for its purported health benefits. However, it’s important to note that many of the benefits of sea moss specifically are anecdotal and lack solid scientific evidence.

There are more studies on the health benefits of seaweed and algae than on sea moss itself. Still, some of these benefits may also apply to sea moss because they grow in similar environments.

However, scientists need to conduct more research on sea moss to investigate its particular effects.

Some of the main potential benefits of using sea moss may include (8Trusted Source

• May support thyroid health. Seaweeds are rich in iodine, a micronutrient      necessary for healthy thyroid function (9Trusted Source).
• May support immunity. One      study in salmon found that supplemental seaweed improved immune modulation      and immune response. Scientists need to do more research to see whether it      also supports immunity in humans (10Trusted      Source).
• May improve gut health. Seaweeds are a good source of live bacteria and      fiber, which both support a healthy gut microbiome (11Trusted Source, 12Trusted      Source).
• May help support weight loss. Seaweeds and microalgae are rich in fiber that can help      you feel full and prevent overeating. Studies have shown that a compound      in seaweed called fucoxanthin promoted fat metabolism in rats (13Trusted      Source, 14Trusted Source, 15Trusted Source).
• May promote heart health. Some studies have found that seaweed reduces LDL      (bad) cholesterol and acts as a blood thinner, which may help reduce the      risk of heart disease (16Trusted
• May improve blood sugar management. One study found that the compound fucoxanthin in seaweed      reduced high blood sugar. Another study found that a compound in seaweed      called alginate prevented blood sugar spikes in pigs (19Trusted      Source, 20Trusted Source).
• Anecdotal benefits for fertility. There’s no scientific evidence that sea moss      specifically promotes fertility in men or women. However, some people use      it as a traditional fertility treatment. Scientists need to investigate this further.

While the potential health benefits of sea moss are promising, it’s important to note that most of the research is based on seaweed, not sea moss specifically. The studies were also conducted in test tubes or animals, not in humans.

Therefore, scientists need to do much more human research on the health effects of sea moss.

SUMMARY

Animal and test-tube studies on seaweed, not sea moss specifically, suggest it may benefit weight loss, heart health, and blood sugar management, as well as thyroid, gut, and immune health. Scientists need to investigate the effects of sea moss in humans.

EVERYDAY HEALTH

By Kristeen Cherney, PhD and Emma PenrodMedically Reviewed by Justin Laube, MD

Reviewed: July 14, 2022

What Is Sea Moss (Irish Moss)? A Complete Scientific Guide

By Kristeen Cherney, PhD and Emma PenrodMedically Reviewed by Justin Laube, MD

Reviewed: July 14, 2022

Our stories are medically reviewed and medically fact-checked by board-certified specialists to ensure that all factual statements about medical conditions, symptoms, treatments, procedures and tests, standards of care, and typical protocols are accurate and reflect current guidelines as well as the latest research.

f you’ve perused some of the latest superfoods and weight loss supplement fads online, you may have come across a supplement called sea moss, sometimes referred to as Irish moss.

“Irish moss is a superfood that has recently gained widespread popularity after glowing endorsements from celebrities like Kim Kardashian,” says Jessica Cho, MD, the founder of Wellness at Century City, her personal practice in Los Angeles.

The scientific name for sea moss is Chondrus crispus, which is a species of red algae that grows on rocky coastlines along the Atlantic coast across the British Isles, continental Europe, and North America.

It is a small, spiky or frilly seaweed that resembles red leaf lettuce, except it can come in a variety of colors — from yellow-green to dark purple.

The main component of sea moss is carrageenan, a gelatinous substance used to thicken a variety of foods, including dairy products, processed meats, and infant formula.

Carrageenan is also used in cosmetics and medications.

Sea moss has a long history of being used for purported nutritional and medicinal benefits. Some evidence points to the use of sea moss in Chinese medicine as far back as 600 B.C., and by 400 B.C., it had become a food source across the British Isles. Sea moss proved an important source of nutrition in Ireland during the Great Famine in the mid-19th century, and Irish immigrants later established seaweed farms in the United States. Following agar shortages during World War II, sea moss increased in popularity as a replacement food thickener and emulsifier.

Today, some of those same properties have sea moss making an appearance in the aforementioned wellness products — and there might be some merit to the claims, though research is limited and sea moss may not be appropriate for everyone.

What is sea moss good for?

Sea moss itself hasn’t been widely studied for potential health benefits. But like other plant foods, seaweed is rich in fiber and minerals, all of which may potentially boost your immunity, as well as a healthy heart and digestive system.

What's the difference between sea moss and Irish moss?

Sea moss is another name for Irish moss, and the scientific name for both is Chondrus crispus. But importantly these are not the same as “seaweed.” As these terms may be used interchangeably, it’s important to know each one if you’re looking for Irish or sea moss in a product or supplement. 

Does sea moss help you lose weight?

While some research has found potential anti-obesity effects of seaweed in animal studies, such studies need to be replicated in humans for confirmation and are not specifically focused on sea moss.

“[Sea moss] is rich in iodine, among other vital nutrients. As a result, it may offer health benefits including improved heart health, improved blood sugar regulation, and reduced risk of cancer,” says Kristin Gillespie, RD, who is based in Virginia Beach, Virginia.

Nutritionally, sea moss is also calorie-free and contains iron and phosphorus. The U.S. Department of Agriculture lists the following nutrition facts for 2 tablespoons (tbsp) of sea moss:

• Calories: 5
• Total fat: 0.02 grams (g)
• Protein: 0.2g
• Carbohydrates: 1.2g
• Dietary fiber: 0.13g
• Sugars: 0.06g
• Calcium: 7.2 milligrams (mg)
• Iron: 0.89mg
• Magnesium: 14.4mg
• Potassium: 6.3mg
• Vitamin A: 0.6 microgram (mcg)
• Vitamin C: 0.3mg
• Vitamin K: 0.5mcg

But sea moss really stands out for its iodine content, says Robin Foroutan, RDN, a registered dietitian with The Morrison Center in New York City. 

“There are a lot of chemical compounds in our environment that can block iodine,” says Foroutan, adding that this mineral is essential to thyroid function. Specifically, iodine helps the body produce thyroid hormones, which affect metabolism. Pregnant women and people who follow a vegan or dairy-free diet are more likely to have trouble getting enough iodine. In pregnancy and infancy, thyroid hormones support healthy development of the brain and bones.

 What Are the Possible Health Benefits of Sea Moss?

Sea moss isn’t a routine part of most Americans’ diets, and research on its purported health benefits is limited. Most studies focus on seaweed more generally.

Even so, Foroutan says, sea moss may play a role in promoting health and fighting disease.

“This particular type of sea algae has been used medicinally around the world for a long time,” she says. “When a food has been around medicinally that long, there’s usually some truth to it, even if we don’t have the research to support it.”

Indeed, special attention has been paid to carrageenan, which contains the following properties:

• Antibacterial
• Antiviral
• Anti-tumor
• Anti-thrombotic
• Anticoagulant
• Anti-hyperlipidemic
• Immunomodulatory

Below are some of the other proposed health benefits associated with sea moss that may warrant further studies in humans. Keep in mind that the data so far mostly comes from studies in animals, not people, and some of the purported perks are only theoretical and require further research to be confirmed.

The studies that have focused on sea moss in particular primarily support the idea that the when consumed in supplement form, this algae may benefit gut health, says Kristin Kirkpatrick, RDN, who is with the Cleveland Clinic Wellness Institute based in Denver, Colorado. Sea moss contains prebiotic mucilage, a type of fiber that provides food with beneficial gut microbes, which may in turn promote gut health.

For instance, one study examined the prebiotic effects of sea moss in rats, and suggested the moss had a positive effect on gut health, gut microbes, and immune response. More studies are necessary to see if sea moss has the same effect in humans, though.

As mentioned, sea moss may support the immune system. One review suggests its carrageenans possibly contain anti-tumor properties. The authors cite other research that notes red seaweed may also offer antibacterial and antifungal benefits.

One potential mechanism: Mucilage has a gelatinous texture, and sea moss could theoretically help soothe mucus membranes in the respiratory and digestive tracts, Foroutan says. (Mucus membranes produce mucus, which helps trap and remove germs from the body.)

While no clinical studies support sea moss as a weight loss remedy, one review of macroalgae (seaweed) from in vivo and in vitro studies found possible anti-obesity effects. While human studies are needed to confirm these benefits, researchers found that macroalgae extracts may promote weight loss via thermogenesis, a healthier gut microbiota, and fatty acid oxidation (though these effects have not been studied on microalgae like sea moss).

One theoretical reason sea moss may support weight loss: Its fiber content can help dampen appetite, Foroutan says.

Fiber is satiating, meaning it can help you feel full for longer and reduce the likelihood that you’ll overeat — but keep in mind that this effect hasn’t been formally studied in sea moss.

Adding seaweed to your diet could help reduce the risk of cardiovascular disease, thanks to the algae’s nutritional and antioxidant profile, according to another review (but again, this research did not specifically examine sea moss).

One study discovered possible anti-tumor potential in sea moss after ultrasound-assisted extraction of its compounds, which inhibited the growth of some human cancer cell lines in the lab. Researchers noted this may be due to its antioxidant compounds.

Such anti-cancer properties may also be attributed to the carrageenan content in sea moss and may even be helpful when combined with chemotherapy treatments.

But more human studies are needed to confirm the potential role of sea moss in cancer prevention and treatment.

According to a review, carrageenan found in red algae may help protect against human papillomavirus (HPV) infections. While more studies are needed, researchers believe that carrageenan may complement other preventive HPV therapies, such as vaccines.

Sea moss also appears to be growing in popularity as an ingredient in natural skin care products, though research into this use is lacking. In addition to its nutrients and antioxidants, sea moss contains sulfur, which can help treat acne as well as fungal and yeast infections of the skin, says Karan Lal, MD, a board-certified dermatologist with Schweiger Dermatology Group in Hackensack, New Jersey. Amino acids in the moss, such as arginine, may also benefit the skin by promoting the replacement of dead skin cells, Dr. La.