Does Sea Moss Have Health Benefits? Or Is It Just a Fad?

Sea moss is a buzzy wellness trend popular on social media. Influencers promote it for a long list of supposed health benefits. They claim it can boost your energy, improve libido, and clear your skin, among other things. 

But are these claims true? Let’s take a look at what the research says about sea moss and what to know if you’re considering adding it to your routine.

What is sea moss?

Sea moss is a type of seaweed that grows along the Atlantic coasts of North America, Europe, and the Caribbean. Also known as Irish moss or red algae, sea moss has been used for centuries in traditional medicine.

Like other seaweeds, sea moss contains many nutrients, including: 

• Iodine

• Magnesium

• Iron

• Potassium

But what makes sea moss unique is its texture. It forms a jelly-like substance when soaked. That gel-like quality comes from carrageenan, a natural fiber in sea moss. 

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Is sea moss good for you?

Sea moss contains vitamins, minerals, and antioxidants that can support your overall health. But it’s important to note that human studies on sea moss itself are fairly limited. Here’s what we know so far about the potential health benefits of sea moss.

Supports thyroid health

Sea moss is a natural source of iodine. Your thyroid gland needs iodine to make the hormones that regulate metabolism, energy, and mood. Not getting enough iodine can increase your risk of hypothyroidism. This is a condition in which your thyroid doesn't produce enough thyroid hormone. 

Iodine deficiency is rare in the U.S. But you're at greater risk of it in these cases:

• You don't use iodized salt.

• You're pregnant (since pregnant people need about 50% more iodine).

• You're vegan or eat few dairy or seafood products.

• You eat high amounts of foods containing goitrogens. These are substances that make it harder for your body to produce thyroid hormone. Foods high in goitrogens include soy, cabbage, broccoli, cauliflower, and Brussels sprouts.

If you’re not getting enough iodine from your diet, supplementing with sea moss might help. But keep in mind that the amount of iodine in sea moss can vary widely. And getting too much can also be a concern (more on this below).

May boost immune function

Lab and animal studies suggest that sea moss has antiviral and antimicrobial properties. This is because sea moss contains sulfated polysaccharides. These are complex sugars that help fight off viruses and harmful bacteria by making it difficult for them to attach to and infect cells. 

Sea moss also contains small amounts of nutrients that play a role in immunity, including:

• Zinc

• Vitamin C

• Iron

And we know that seaweeds (as a broad category) contain other compounds — like amino acids and omega-3 fatty acids. These compounds have antioxidant, antiviral, and anti-inflammatory properties. 

Still, we need more human research on sea moss specifically to understand how it affects the immune system in real life. 

Can support gut health

Sea moss is rich in carrageenan, a type of fiber that acts as a prebiotic. Prebiotics support the good bacteria in your gut by serving as their food. By helping to maintain the balance of bacteria in your microbiome, prebiotics support digestion, immune health, and inflammation levels.

Note that carrageenan can be extracted from sea moss for use as a food additive. This processed version of carrageenan is common in packaged foods. And it has been linked to digestive issues. It is different from the naturally occurring carrageenan in sea moss and other seaweeds. 

Contains antioxidants

Like other seaweeds, sea moss contains polyphenols and flavonoids, which are powerful antioxidants. Antioxidants are nutrients that help protect your body’s cells from damage caused by unstable molecules called free radicals. If too many free radicals build up, it can lead to oxidative stress. Over time, oxidative stress can cause inflammation and increase your risk of conditions including:

• Cancer

• Type 2 diabetes

• Heart disease

• Alzheimer’s and Parkinson’s disease

Sea moss isn’t a magic cure. But getting antioxidants in your diet from a variety of foods and drinks can help support your body’s defense system.

Sea moss nutrition facts

The exact nutrient content of sea moss varies depending on its form and where it’s harvested. 

Here are the nutrients in 2 tbsp (30 g) of one popular brand of sea moss gel:

• Calories: 15

• Protein: 0.5 g

• Fiber: 0.4 g (1% DV, or Daily Value)

• Sodium: 20 mg (less than 1% DV)

• Calcium: 22 mg (2% DV)

• Iron: 2.7 mg (15% to 34% DV)

• Magnesium: 43 mg (10% DV)

• Potassium: 19 mg (less than 1% DV)

• Phosphorus: 47 mg (4% DV)

How do you take sea moss?

You can take sea moss in different forms, including:

• Gel: Sea moss gel is made by soaking and blending raw sea moss into a thick, smooth paste. It comes in many flavors, from strawberry to apple cinnamon. You can mix it into smoothies, teas, and juices. Or you can just eat it by the spoonful. Plain sea moss gel has an earthy, fishy taste. But the added flavoring masks the natural taste. 

• Gummies: Sea moss gummies can be a convenient, tasty option. But gummy supplements often contain added sugar as well as artificial and natural colors and flavorings. Many of these ingredients are linked to health concerns. And gummy vitamins are more likely to have unreliable dosing compared to other forms of supplements.

• Bottled drinks: These beverages usually combine sea moss gel or sea moss extract with fruit juice and herbs. Just be sure to look for unsweetened options.

• Capsule or powder supplements: You can stir sea moss powder into drinks or smoothies. 

When choosing a sea moss supplement, make sure to pick one that has been third-party tested. This ensures a supplement is high quality and contains what its label says it does. 

What are the downsides of sea moss?

Sea moss can be part of a healthy routine, but there are a few things to consider before taking sea moss. 

Too much iodine

Sea moss is higher in iodine than other types of seaweed. Too much iodine can interfere with thyroid function. It may lead to hyperthyroidism, an overactive thyroid gland. If you already get iodine from other sources (like iodized salt or seafood), talk to a healthcare professional before taking a sea moss supplement.

Heavy metals

Like other seaweeds, sea moss may absorb heavy metals from the water where it grows. These heavy metals can include:

• Arsenic

• Cadmium

• Mercury

• Lead

Heavy metal toxicity can cause oxidative stress and negatively impact metabolism. To make sure your supplement doesn’t contain contaminants, choose one that has been third-party tested. Companies that provide third-party testing include: 

• NSF International 

• U.S. Pharmacopeia (USP)

• Good Manufacturing Practice (GMP)

• ConsumerLab

Look for a certification seal on the supplement label to see if it’s vetted by one of these companies. 

Digestive issues

Some people experience bloating or mild digestive discomfort from the fiber in sea moss, particularly the carrageenan. Carrageenan may also trigger inflammation from inflammatory bowel disease (IBD).

Allergic reactions

Though rare, it’s possible to be allergic to sea moss or other types of algae. If you’re trying sea moss for the first time, start with a small amount. 

Possible signs of an allergic reaction include: 

• Hives

• Itching

• Difficulty breathing

If you experience any of these, stop using sea moss and get immediate medical attention.

Interactions with medications

Certain people may need to avoid sea moss, including those who take: 

• Thyroid medications 

• Anticoagulant medications (blood thinners)

If you take these medications, and are considering adding sea moss to your routine, it’s a good idea to talk to a healthcare professional.

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Written by:

Lindsay Boyers, CHNC

Lindsay Boyers, CHNC, is a functional nutritionist, licensed esthetician, writer, and editor with over a decade of experience in evidence-based health, wellness, and skincare writing.

Edited by:

Meredith Hoffa

Meredith Hoffa is a senior health editor at GoodRx, where she leads journalists and clinicians covering various well-being topics, particularly in diet and nutrition.

Reviewed by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

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