Sea moss is a spiny sea vegetable that’s primarily harvested for use in health supplements and as a thickening ingredient in commercial foods.
If you’ve heard about sea moss supplements, you may wonder how you could use them and whether there are other ways to consume sea moss.
This article examines the potential benefits and downsides of sea moss, including its nutritional content and how to prepare it.
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.
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 (
- 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 (
Sea moss is low in calories and fat, and it contains a small amount of protein. It offers a variety of vitamins and minerals and is a good source of iodine and antioxidants.
Today sea moss is mainly used as a source of vitamins and minerals to benefit overall health.
You can most commonly find it in supplement form. Some supplement companies sell it in raw form, as a gel or powder, or as an oral capsule or gummy.
Companies also sell sea moss as a component of supplements combined with turmeric, bladderwrack, and burdock root, claiming this combination benefits overall well-being, especially immunity, thyroid, digestive, and joint health.
Sea moss has a long history of use as a food-thickening agent. It’s the only natural source of carrageenan, a thickener that manufacturers use in foods like ice cream, cottage cheese, nondairy milks, and even baby formula (1,
People primarily harvest sea moss for its carrageenan, a natural food thickener. It has a high micronutrient content, so companies also use it to make consumer health supplements and gels.
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 (
- May support thyroid health. Seaweeds are rich in iodine, a micronutrient necessary for healthy thyroid function (
- 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 (
- May improve gut health. Seaweeds are a good source of live bacteria and fiber, which both support a healthy gut microbiome (
- 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 (
13, 14, 15).
- 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 (
16, 17, 18).
- 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 (
- 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.
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.
One of the main potential downsides of sea moss is that not much research has been conducted on its benefits and nutritional makeup.
As with seaweed, the nutritional value of sea moss can vary greatly, making it difficult to know exactly what it contains and in what amounts. Much of the micronutrient and fatty acid contents of sea vegetables depend on the environment in which they grow (
While it’s a good source of iodine, the iodine content of sea moss and other seaweeds is highly variable. This can put consumers at risk of overconsumption of iodine, which could be problematic (
Taking in too much iodine can lead to hypothyroidism, or underactive thyroid. The thyroid is an important gland located in the lower front of your neck. It’s responsible for growth and metabolism (
Sea moss may also come with a risk of heavy metal consumption, as seaweed is known to absorb and store heavy metals in high amounts (
Still, the risk of toxicity appears to be low. One study examined the levels of 20 heavy metals in 8 types of seaweed from the waters around Europe and Asia. The researchers found that the amounts of heavy metals did not pose serious health risks (
Overall, it’s probably best to consume sea moss in moderation due to these unknowns.
The nutrients in sea moss can vary by the environment in which it was grown. It may contain high levels of iodine or heavy metals. However, current research has not found that sea moss contains toxic levels. Scientists need to do further research on this.
You can prepare sea moss in a number of ways.
Many health food stores and online retailers sell sea moss in its raw, dried form. You can prepare a gel from this at home. This may be one of the most popular ways to consume it.
To prepare a sea moss gel, simply soak raw sea moss in water overnight, then rinse and blend it with new water until smooth. Transfer it to a container with an airtight lid and store it in the refrigerator overnight to gel.
Some supplement companies also offer sea moss that has already been prepared as a gel. According to the manufacturers, you can consume this form directly or add it to food and drinks.
Other ways to consume sea moss include mixing sea moss powder into beverages, sprinkling it over yogurt or oatmeal, and adding it to other meals.
The shelf life of sea moss depends on the form you purchased it in.
While scientific evidence is lacking, many sea moss advocates say that prepared sea moss gel should last a few weeks in the fridge, or you can freeze it.
However, it’s probably best to practice caution and only keep it for 3–5 days, as with most prepared foods and cold storage leftovers, to minimize the risk of foodborne illnesses (27).
You can consume sea moss in supplement or powder form, or use raw sea moss to make a gel at home. You can consume this gel on its own or add it to smoothies and other foods and beverages.
Sea moss, or Chondrus crispus, is a spiny sea vegetable similar to seaweeds and sea algae.
People harvest it for its carrageenan. Companies also use it as a natural thickening agent in commercial foods, as well as for use in consumer health supplements. You can also use it to make a gel at home or easily add it to foods and beverages.
Sea moss is a source of a variety of vitamins and minerals, as well as antioxidants that may benefit overall health. However, its nutritional composition can vary, and by consuming it in large amounts, you may consume high levels of iodine or heavy metals.
Overall, scientists need to do more research on the health effects of sea moss in humans to determine its efficacy in consumer health products. Still, some of the benefits appear promising based on seaweed and sea algae studies.