Most health claims about sea moss are false - here are 4 health benefits backed by science

Most health claims about sea moss are false - here are 4 health benefits backed by science
Sea moss can be added to smoothies for a boost of nutrition. Oscar Wong/Getty Images
  • Sea moss benefits may include supporting thyroid health, weight loss, and gut health.
  • Unproven benefits of sea moss include enhancing hair, clearing the skin, and treating cancer.
  • Some sea moss contains heavy metals and microbes, so avoid if pregnant or immunocompromised.

Sea moss is an edible form of seaweed that has become increasingly popular for its health benefits, especially among celebrities like Kim Kardashian.

You can buy sea moss as a supplement or in its raw form at specialty health stores. Just remember that if you buy raw sea moss, cook it to kill off any harmful microbes, says Eleana Kaidanian, RD, CDN, a registered dietitian with the private practice Long Island Nutritionist.

Warning: Depending on where it is grown, sea moss could contain heavy metals, like mercury and lead, or other toxins, says Kaidanian. Therefore, if you're pregnant, breastfeeding, immunocompromised, or taking anticoagulant medication, you should avoid sea moss.

While sea moss is a nutrient-rich supplement, more research is needed to understand the full scope of its health benefits and risks, says Lon Ben-Asher, MS, RDN, LDN, a nutrition specialist and educator at Pritikin Longevity Center and Spa. Here are some of the potential benefits that preliminary studies have looked into thus far.

1. Full of nutrients

Most of sea moss's benefits are thanks to its impressive nutrient profile. For example, two tablespoons (10 grams) of raw sea moss contains:


NutrientAmountDaily Value (DV)
Calories4.9 --
Carbs1.23 g0.5%
Fat0.02 g0.02%
Protein0.15 g0.3%
Iodine470 mg313%
Iron0.89 mg4.9%
Copper0.02 mg1.6%
Magnesium14.4 mg3.43%
Manganese0.04 mg1.6%
Zinc0.195 mg1.7%
Vitamin B2 (riboflavin)0.05 mg3.6%
Vitamin B60.01 mg4.1%
Vitamin B9 (folate)18.2 mcg4.55%

2. May help with weight loss

"Sea moss may support weight loss due to its carrageenan content," says Ben Asher.

Carrageenan is a type of fiber that slows down digestion, which can help keep you fuller for longer and potentially cut down on the total calories you eat each day, says Ben-Asher.

Important: Adult females should aim to get around 21 to 25 grams of fiber per day, whereas adult males require around 30 to 38 grams.

In fact, a small 2011 study found those who consumed a drink with seaweed fiber reported higher levels of satiety and reduced appetite five hours later compared to the placebo.

3. Supports thyroid health

"Sea moss is also a good source of iodine, which is an essential mineral for proper thyroid function and metabolism regulation," says Ben-Asher.


The thyroid is a small gland at the base of the neck that produces several important hormones that regulate bodily functions like weight management and mood.

In fact, a small 2014 study of healthy women found those who took 0.5 grams of seaweed per day for two weeks had improved iodine levels and higher levels of thyroid-stimulating hormone (TSH).

TSH regulates hormones responsible for:

  • Weight
  • Body temperature
  • Mood
  • Muscle strength
  • Energy production

Warning: Consuming sea moss in large quantities, particularly from supplements, may cause iodine toxicity, which can adversely affect the thyroid gland and lead to health conditions like hyperthyroidism and goiters, says Kaidanian. You should not exceed 1,100 micrograms of iodine a day.

4. May act as a prebiotic

In addition to keeping you full, the carrageenan in seaweed also functions as a prebiotic. Prebiotics feed the healthy bacteria in your gut that help with digestion, immunity, and disease prevention.


Thus far, research on sea moss's role in gut health has only been conducted in animals, meaning its function as a prebiotic in humans has yet to be studied. But so far, results from animal studies look promising.

For example, a 2020 review found that the prebiotics in sea moss fostered the growth of healthy gut microbiota in rats. In some studies, this resulted in weight loss and a reduction in harmful pathogens like E. coli.

Other potential benefits

There are many other health claims about the benefits of sea moss, but most of these are anecdotal and lack scientific evidence. Claims about sea moss that you should be skeptical of include:

  • Clearing skin
  • Enhancing hair
  • Improving fertility
  • Strengthening immunity
  • Detoxifying
  • Suppressing cancer

Insider's takeaway

Given the popularity of sea moss as a health food and supplement, the scientific community has been studying the benefits and risks associated with this sea vegetable. These include its nutrition content, prebiotic properties, and benefits for thyroid health.

However, further research is needed to establish a recommended dosage and usage of sea moss, says Kaidanian.

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