Before sea moss became the buzzy superfood endorsed by everybody from Erewhon to Bella Hadid, it was a centuries-old remedy for vitality. Originating on Irish and Caribbean shores, sea moss gel was harvested by coast dwellers for its benefits well before the wellness world caught on. Early herbalists used it to ward off scurvy, and later as a food source because of its high nutrient density. Some cultures even used the gel as a libido enhancer.
As with many traditional medicines, there has historically been little clinical research to support the reputed health claims. However, in recent years, studies have begun to investigate the properties of sea moss, revealing its anti-viral, anti-inflammatory, and anti-tumor potential.
What science does know is that the seaweed is home to dozens of essential nutrients, vitamins, and minerals, including magnesium and vitamin C. “Sea moss has gained popularity largely because it’s rich in trace minerals, especially iodine, which is essential for healthy thyroid function,” board-certified endocrinologist Dr Jolene Brighten confirms. “The thyroid gland uses iodine to produce thyroid hormones, which regulate metabolism, energy, mood, and even menstrual regularity.” Iodine also plays a role in immunity, and combined with other nutrients in sea moss, can help give your defences a boost.
Read on for a guide to the best sea moss supplements we’ve tried and their benefits, plus expert advice on how best to use them.
What is sea moss good for?
Sea moss is high in mucilage (a sticky substance made by plants), which can soothe irritated membranes in the respiratory tract. It can be beneficial during flu season thanks to its antibacterial properties and potassium chloride content, which helps dissolve phlegm.
The high fiber content of sea moss may also help improve digestion. Emerging studies suggest it is rich in prebiotics which can support a healthy gut microbiome.
Sea moss is rich in lipids, antioxidants, and vitamins A, C and E, which make it great for topical application on skin. Used as a mask, it can boost hydration and calm inflammation; when ingested, its high vitamin C content helps support healthy collagen production.
Sea moss contains iron and magnesium, both of which can help combat fatigue.
Does sea moss actually work?
There is plenty of anecdotal evidence to suggest sea moss has benefits for health. However, when it comes to replicable clinical trials, research validating the claims is limited. Studies supporting its medicinal uses have so far only been preliminary.
Dr. Jolene Brighten adds that the mineral content of sea moss is highly variable depending on the species and growing conditions, which makes consistent dosing difficult. As supplements are rarely standardized, it’s worth noting that effects may vary from brand to brand.
“Despite advertising from several providers of sea moss products, there are no scientific studies to be found (on PubMed, the federal source for published scientific work) claiming any effects on blood pressure or cardiovascular health,” notes Dr. Ernst von Schwarz, a cardiologist and clinical professor of medicine at UCLA. “Therefore, it might be worthwhile and timely to conduct a study on sea moss’s effects on the vascular system.”
Who should not use sea moss?
Because of its iodine content, people with thyroid disorders—in particular those with hyperthyroidism—should abstain from sea moss, says Dr. von Schwarz. And even in healthy people, excessive consumption should be avoided. Dr. Brighten concurs: “More isn’t always better, especially when it comes to iodine. Excessive iodine intake can actually disrupt thyroid function, particularly in people with autoimmune thyroid disease like Hashimoto’s or Graves.”
If you are pregnant, or allergic to seafood, sea moss is not recommended. Always consult your doctor for the best medical advice when introducing supplements, especially if you are taking any other prescribed medications.
What to look for in a good sea moss supplement
Sea moss gels that are wild harvested from protected or pristine waters are the best form to buy, because they are likely to be free from additives and contaminants. They also keep the full nutritional profile of the algae and trace minerals from the ocean in which they are sourced. These gels are generally absorbed better by the body, too.
Pool grown, or farmed sea moss is often more cheaply available because it can be mass produced year round in a controlled environment. However, these options do not grow with access to ocean minerals and may be processed with additives.
“Some authors are concerned about the potential of heavy metal contamination,” says Dr. von Schwarz, which is a common complaint in some powdered supplements. If you prefer shopping sea moss powders or capsules, look for dried sea moss that is independently tested for safety and purity. Avoid formulas of obscure origins, or those with added preservatives and artificial bulking agents in their blend.
Meet the experts:
- Dr. Ernst von Schwarz MD, PHD is a cardiologist and clinical professor of medicine at UCLA, who has published hundreds of scientific papers in international Medical Journals.
- Dr. Jolene Brighten is a board-certified endocrinologist and expert author of several women’s hormonal health books.
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