Table of ContentsView AllTable of ContentsNutritionUsesSide EffectsPrecautionsDosageDrug InteractionsSimilar SupplementsSources of Sea Moss and What to Look For
Table of ContentsView All
View All
Table of Contents
Nutrition
Uses
Side Effects
Precautions
Dosage
Drug Interactions
Similar Supplements
Sources of Sea Moss and What to Look For
Sea moss (Irish moss) is a type of red seaweed. In general, seaweeds are rich sources of proteins and minerals. They also contain fiber and plant chemicals that may promote good health.
There are several other health claims for sea moss. But most available research is either done in the lab or the sea moss is tested in animals, not humans. For this reason, there isn’t enough data to support these claims. What’s more, there are some safety concerns with sea moss.
In the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it regulates prescription drugs. That means some supplement products may not contain what the label says. Whenchoosing a supplement, look for independently tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.
Irish moss on the sand.Tina Horne / Getty Images
Tina Horne / Getty Images
Ten grams—about 2/3of a cup—of driedseaweedcontains the following nutrients in kilocalories (kcal), grams (g), milligrams (mg), and micrograms (mcg):
Health Claims
While more extensive research is necessary, people might use sea moss for various—often overstated—health claims. Keep in mind that no supplement is intended to treat, cure, or prevent disease.
Digestive System Support
Health claims about sea moss include digestive system support. Data from an animal study suggested that sea moss may have some prebiotic effects.A diet with sea moss may encourage the growth and activity of “good” bacteria that naturally exist in your body.
While sea moss seemed to support gut health in this animal study, a review article hinted at the opposite effects ofcarrageenan—a substance in sea moss.According to this review article, carrageenan triggered worseninginflammatory bowel disease(IBD) symptoms. A carrageenan-free diet may relieve IBD symptoms.
Further research on sea moss is necessary. Until more data is available, healthcare providers may recommend limiting how much sea moss and carrageenan you take.
Thyroid Health Support
Supporting thyroid health is another potential health claim for sea moss.This might be because sea moss containsiodine, an essential nutrient your body uses to make thyroid hormones.These hormones help with bodily functions, including weight regulation, temperature, and energy levels.
Iodine can affect thyroid function, especially in infants, the developing fetus, and older adults over 65. If you’re using sea moss, a healthcare provider may want to monitor your iodine levels closely and watch forthyroid-related symptoms.
Sea Moss and Iodine
Immune System Support
Sea moss may support the immune system, though more research is needed. Animal studies of rats and roundworms suggest some benefits for the immune system (the body’s defense system).
One review article, however, reports that carrageenan—a substance in sea moss—triggered some inflammation (swelling).Inflammation is typically a defensive immune response against a threat like infection.There are also reports of severe allergic reactions to carrageenan.
Like many medications and natural products, side effects are possible with sea moss. Generally, the amount of iodine in 3 to 4 g of sea moss daily is likely safe.But if you have higher-than-normal iodine levels, some symptoms may include:
Aside from iodine-related symptoms, weight loss might be another side effect.
There is little information about the common side effects of sea moss, but carrageenan—a substance in sea moss—is on the Food and Drug Administration’s (FDA) list of substances added to food.
Some severe possible side effects may include:
If you’re having a severe allergic reaction or if any of your symptoms feel life-threatening, call 911 and get medical help right away.
A healthcare provider may advise against sea moss if any of the following applies to you:
Dosage: How Much Sea Moss Should I Take?
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.
There are very few human clinical trials on sea moss, and there are no formal guidelines on the appropriate dosage of sea moss for any condition.
Generally, 3 to 4 g of dried sea moss every day is likely safe in adults.The specific dose may vary based on the amount of iodine in the specific source of sea moss, other iodine sources in your diet, your age, and your medical condition.Capsules are a common form.
Symptoms of overdoses with sea moss are likely similar to its potential common and serious side effects—but excessive and severe. For example, too much iodine in sea moss might result in a coma.
Aside from possible iodine poisoning, some sea moss products contain toxic substances—like lead, mercury, and arsenic. So, poisonings from these substances are also possible. If you suspect you’re experiencing life-threatening side effects, seek immediate medical attention.
The recommended amount of iodine is 150 mcg per day for most adults. Children usually need less, and pregnant or breastfeeding people typically need more.
There is limited information about possible medication interactions with sea moss.
Possible interactions are based on the health claims or potential side effects of sea moss.Some people should not use sea moss, or should use caution if also taking:
It is essential to carefully read a supplement’s ingredients list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.
Sea moss might have effects on digestion, thyroid, and immune health.
Other potentially similar supplements may include:
There are several sources of sea moss, but health nutrition guidelines typically place more importance on food sources to improve the diet.
Although food sources—like iodized salt—are preferable over sea moss, some people may need supplements.People with vegan or vegetarian diets are likelier to experience iodine deficiency.
Supplement Facts
Summary
Sea moss is a red seaweed. Some health claims about sea moss include benefits for digestion, thyroid function, and immune health. However, more research is needed to identify and understand the health benefits of sea moss.
What’s more, there are several safety concerns with sea moss. For these reasons, it’s essential to ensure an accurate diagnosis and treatment of any health conditions. Before you take sea moss, you should ask a pharmacist or healthcare provider about the benefits and safety of taking sea moss.
23 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.The Department of Defense Dietary Supplement Resource: Operation Supplement Safety.Sea moss in dietary supplements.USDA FoodData Central.Seaweed, raw.Liu J, Kandasamy S, Zhang J, et al.Prebiotic effects of diet supplemented with the cultivated red seaweedChondrus crispusor with fructo-oligo-saccharide on host immunity, colonic microbiota and gut microbial metabolites.BMC Complementary Medicine and Therapies. 2015;15:279. doi: 10.1186%2Fs12906-015-0802-5Borsani B, De Santis R, Perico V, et al.The role of carrageenan in inflammatory bowel diseases and allergic reactions: Where do we stand?.Nutrients. 2021;13(10):3402. doi: 10.3390%2Fnu13103402Smyth PPA.Iodine, seaweed, and the thyroid.European Thyroid Journal. 2021;10(2):101-108. doi: 10.1159%2F000512971Endocrine Society.Thyroid and parathyroid hormones.Khalifa M, Aftab HB, Kantorovich V.“Fueling the fire”—Irish sea-moss resulting in Jod-Basedow phenomenon in a patient with Grave’s disease.Journal of the Endocrine Society. 2021;5(Suppl 1):A906. doi: 10.1210%2Fjendso%2Fbvab048.1849Kulshreshtha G, Borza T, Rathgeber B, et al.Red seaweedsSarcodiotheca gaudichaudiiandChondrus crispusdown regulate virulence factors ofSalmonella enteritidisand induce immune responses inCaenorhabditis elegans.Frontiers in Microbiology. 2016;7:421. doi: 10.3389%2Ffmicb.2016.00421Chen L, Deng H, Cui H, et al.Inflammatory responses and inflammation-associated diseases in organs.Oncotarget. 2018;9(6):7204-7218. doi: 10.18632%2Foncotarget.23208Darias-Rosales J, Rubio C, Gutierrez AJ, et al.Risk assessment of iodine intake from the consumption of red seaweeds (Palmaria palmataandChondrus crispus).Environmental Science and Pollution Research. 2020;27:45737-45741. doi: 10.1007/s11356-020-10478-9National Institutes of Health: Office of Dietary Supplements.Iodine.Food and Drug Administration.Substances added to food (formally EAFUS).Cherry P, O’Hara C, Magee PJ, et al.Risks and benefits of consuming edible seaweeds.Nutrition Reviews. 2019;77(5):307-329. doi: 10.1093%2Fnutrit%2Fnuy066Centers for Disease Control and Prevention.Breastfeeding: iodine.American Thyroid Association.Clinical Thyroidology for the Public.National Center for Complementary and Integrative Health.Ashwagandha.National Center for Complementary and Integrative Health.Echinacea.National Center of Complementary and Integrative Health.7 tips: irritable bowel syndrome and complementary health approaches.National Center for Complementary and Integrative Health.Soy.National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: sea moss.Lentjes MAH.The balance between food and dietary supplements in the general population.Proceedings of the Nutrion Society. 2019;78(1):97-109. doi: 10.1017%2FS0029665118002525United States Department of Agriculture: FoodData Central.Sea moss.American Thyroid Association.ATA statement on the potential risks of excess iodine ingestion and exposure.
23 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.The Department of Defense Dietary Supplement Resource: Operation Supplement Safety.Sea moss in dietary supplements.USDA FoodData Central.Seaweed, raw.Liu J, Kandasamy S, Zhang J, et al.Prebiotic effects of diet supplemented with the cultivated red seaweedChondrus crispusor with fructo-oligo-saccharide on host immunity, colonic microbiota and gut microbial metabolites.BMC Complementary Medicine and Therapies. 2015;15:279. doi: 10.1186%2Fs12906-015-0802-5Borsani B, De Santis R, Perico V, et al.The role of carrageenan in inflammatory bowel diseases and allergic reactions: Where do we stand?.Nutrients. 2021;13(10):3402. doi: 10.3390%2Fnu13103402Smyth PPA.Iodine, seaweed, and the thyroid.European Thyroid Journal. 2021;10(2):101-108. doi: 10.1159%2F000512971Endocrine Society.Thyroid and parathyroid hormones.Khalifa M, Aftab HB, Kantorovich V.“Fueling the fire”—Irish sea-moss resulting in Jod-Basedow phenomenon in a patient with Grave’s disease.Journal of the Endocrine Society. 2021;5(Suppl 1):A906. doi: 10.1210%2Fjendso%2Fbvab048.1849Kulshreshtha G, Borza T, Rathgeber B, et al.Red seaweedsSarcodiotheca gaudichaudiiandChondrus crispusdown regulate virulence factors ofSalmonella enteritidisand induce immune responses inCaenorhabditis elegans.Frontiers in Microbiology. 2016;7:421. doi: 10.3389%2Ffmicb.2016.00421Chen L, Deng H, Cui H, et al.Inflammatory responses and inflammation-associated diseases in organs.Oncotarget. 2018;9(6):7204-7218. doi: 10.18632%2Foncotarget.23208Darias-Rosales J, Rubio C, Gutierrez AJ, et al.Risk assessment of iodine intake from the consumption of red seaweeds (Palmaria palmataandChondrus crispus).Environmental Science and Pollution Research. 2020;27:45737-45741. doi: 10.1007/s11356-020-10478-9National Institutes of Health: Office of Dietary Supplements.Iodine.Food and Drug Administration.Substances added to food (formally EAFUS).Cherry P, O’Hara C, Magee PJ, et al.Risks and benefits of consuming edible seaweeds.Nutrition Reviews. 2019;77(5):307-329. doi: 10.1093%2Fnutrit%2Fnuy066Centers for Disease Control and Prevention.Breastfeeding: iodine.American Thyroid Association.Clinical Thyroidology for the Public.National Center for Complementary and Integrative Health.Ashwagandha.National Center for Complementary and Integrative Health.Echinacea.National Center of Complementary and Integrative Health.7 tips: irritable bowel syndrome and complementary health approaches.National Center for Complementary and Integrative Health.Soy.National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: sea moss.Lentjes MAH.The balance between food and dietary supplements in the general population.Proceedings of the Nutrion Society. 2019;78(1):97-109. doi: 10.1017%2FS0029665118002525United States Department of Agriculture: FoodData Central.Sea moss.American Thyroid Association.ATA statement on the potential risks of excess iodine ingestion and exposure.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
The Department of Defense Dietary Supplement Resource: Operation Supplement Safety.Sea moss in dietary supplements.USDA FoodData Central.Seaweed, raw.Liu J, Kandasamy S, Zhang J, et al.Prebiotic effects of diet supplemented with the cultivated red seaweedChondrus crispusor with fructo-oligo-saccharide on host immunity, colonic microbiota and gut microbial metabolites.BMC Complementary Medicine and Therapies. 2015;15:279. doi: 10.1186%2Fs12906-015-0802-5Borsani B, De Santis R, Perico V, et al.The role of carrageenan in inflammatory bowel diseases and allergic reactions: Where do we stand?.Nutrients. 2021;13(10):3402. doi: 10.3390%2Fnu13103402Smyth PPA.Iodine, seaweed, and the thyroid.European Thyroid Journal. 2021;10(2):101-108. doi: 10.1159%2F000512971Endocrine Society.Thyroid and parathyroid hormones.Khalifa M, Aftab HB, Kantorovich V.“Fueling the fire”—Irish sea-moss resulting in Jod-Basedow phenomenon in a patient with Grave’s disease.Journal of the Endocrine Society. 2021;5(Suppl 1):A906. doi: 10.1210%2Fjendso%2Fbvab048.1849Kulshreshtha G, Borza T, Rathgeber B, et al.Red seaweedsSarcodiotheca gaudichaudiiandChondrus crispusdown regulate virulence factors ofSalmonella enteritidisand induce immune responses inCaenorhabditis elegans.Frontiers in Microbiology. 2016;7:421. doi: 10.3389%2Ffmicb.2016.00421Chen L, Deng H, Cui H, et al.Inflammatory responses and inflammation-associated diseases in organs.Oncotarget. 2018;9(6):7204-7218. doi: 10.18632%2Foncotarget.23208Darias-Rosales J, Rubio C, Gutierrez AJ, et al.Risk assessment of iodine intake from the consumption of red seaweeds (Palmaria palmataandChondrus crispus).Environmental Science and Pollution Research. 2020;27:45737-45741. doi: 10.1007/s11356-020-10478-9National Institutes of Health: Office of Dietary Supplements.Iodine.Food and Drug Administration.Substances added to food (formally EAFUS).Cherry P, O’Hara C, Magee PJ, et al.Risks and benefits of consuming edible seaweeds.Nutrition Reviews. 2019;77(5):307-329. doi: 10.1093%2Fnutrit%2Fnuy066Centers for Disease Control and Prevention.Breastfeeding: iodine.American Thyroid Association.Clinical Thyroidology for the Public.National Center for Complementary and Integrative Health.Ashwagandha.National Center for Complementary and Integrative Health.Echinacea.National Center of Complementary and Integrative Health.7 tips: irritable bowel syndrome and complementary health approaches.National Center for Complementary and Integrative Health.Soy.National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: sea moss.Lentjes MAH.The balance between food and dietary supplements in the general population.Proceedings of the Nutrion Society. 2019;78(1):97-109. doi: 10.1017%2FS0029665118002525United States Department of Agriculture: FoodData Central.Sea moss.American Thyroid Association.ATA statement on the potential risks of excess iodine ingestion and exposure.
The Department of Defense Dietary Supplement Resource: Operation Supplement Safety.Sea moss in dietary supplements.
USDA FoodData Central.Seaweed, raw.
Liu J, Kandasamy S, Zhang J, et al.Prebiotic effects of diet supplemented with the cultivated red seaweedChondrus crispusor with fructo-oligo-saccharide on host immunity, colonic microbiota and gut microbial metabolites.BMC Complementary Medicine and Therapies. 2015;15:279. doi: 10.1186%2Fs12906-015-0802-5
Borsani B, De Santis R, Perico V, et al.The role of carrageenan in inflammatory bowel diseases and allergic reactions: Where do we stand?.Nutrients. 2021;13(10):3402. doi: 10.3390%2Fnu13103402
Smyth PPA.Iodine, seaweed, and the thyroid.European Thyroid Journal. 2021;10(2):101-108. doi: 10.1159%2F000512971
Endocrine Society.Thyroid and parathyroid hormones.
Khalifa M, Aftab HB, Kantorovich V.“Fueling the fire”—Irish sea-moss resulting in Jod-Basedow phenomenon in a patient with Grave’s disease.Journal of the Endocrine Society. 2021;5(Suppl 1):A906. doi: 10.1210%2Fjendso%2Fbvab048.1849
Kulshreshtha G, Borza T, Rathgeber B, et al.Red seaweedsSarcodiotheca gaudichaudiiandChondrus crispusdown regulate virulence factors ofSalmonella enteritidisand induce immune responses inCaenorhabditis elegans.Frontiers in Microbiology. 2016;7:421. doi: 10.3389%2Ffmicb.2016.00421
Chen L, Deng H, Cui H, et al.Inflammatory responses and inflammation-associated diseases in organs.Oncotarget. 2018;9(6):7204-7218. doi: 10.18632%2Foncotarget.23208
Darias-Rosales J, Rubio C, Gutierrez AJ, et al.Risk assessment of iodine intake from the consumption of red seaweeds (Palmaria palmataandChondrus crispus).Environmental Science and Pollution Research. 2020;27:45737-45741. doi: 10.1007/s11356-020-10478-9
National Institutes of Health: Office of Dietary Supplements.Iodine.
Food and Drug Administration.Substances added to food (formally EAFUS).
Cherry P, O’Hara C, Magee PJ, et al.Risks and benefits of consuming edible seaweeds.Nutrition Reviews. 2019;77(5):307-329. doi: 10.1093%2Fnutrit%2Fnuy066
Centers for Disease Control and Prevention.Breastfeeding: iodine.
American Thyroid Association.Clinical Thyroidology for the Public.
National Center for Complementary and Integrative Health.Ashwagandha.
National Center for Complementary and Integrative Health.Echinacea.
National Center of Complementary and Integrative Health.7 tips: irritable bowel syndrome and complementary health approaches.
National Center for Complementary and Integrative Health.Soy.
National Institutes of Health: Office of Dietary Supplements.Dietary supplement label database: sea moss.
Lentjes MAH.The balance between food and dietary supplements in the general population.Proceedings of the Nutrion Society. 2019;78(1):97-109. doi: 10.1017%2FS0029665118002525
United States Department of Agriculture: FoodData Central.Sea moss.
American Thyroid Association.ATA statement on the potential risks of excess iodine ingestion and exposure.
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