The internet is replete with “superfoods” and supplements that promise to make you healthier and more beautiful, but few have gotten more attention over the past year than sea moss: yes, literal algae. The sea moss trend has exploded since 2020, when (who else?) Kim Kardashian started tweeting about the benefits of the ingredient. In the ensuing years, sea moss has made its way toward the mainstream thanks to health influencers and, most recently, the viral Strawberry Glaze Skin Smoothie at Los Angeles grocer Erewhon.
Promising benefits ranging from weight loss to helping you get hornier, sea moss (or Irish moss, as it is sometimes called) is one of the hottest new health food ingredients. But what is it really? And is it actually worth spending $17 on a sea-moss-infused smoothie?
What is sea moss?
“Sea moss” is a catch-all term for various species of red algae that are found in ocean waters across the globe. The most commonly used varieties are gracilaria and chondrus crispus, and they go by various names throughout the world — ogo in Japanese, Irish moss in Jamaica.
How you consume sea moss might depend on where you are. It’s one of the key ingredients in agar, a gelatin substitute used in Filipino cooking and vegan desserts. As a child in the Caribbean, Dr. Yvonne Noel, an OB-GYN in Brooklyn, drank a special-occasion beverage called Irish moss that was made with milk, nutmeg, cinnamon, and sea moss. “We drank it almost like an eggnog, or what would be considered today as a smoothie,” Noel says. “On occasions where we would have gatherings, it would be one of the favored drinks.” In Jamaica, Irish moss — which takes its name from Irish laborers who came to the island — is a popular canned beverage that is sometimes touted as an aphrodisiac.
In places like Hawaii, Indonesia, and Malaysia, the gracilaria species of sea moss is frequently blanched and added to salads or boiled with fresh juice to make a pudding. In the United States, the current trend makes use of sea moss gel, in which the algae is blended with water to produce a smooth, jelly-like goop. Sometimes fruit is added to the puree to help mask the oceanic, musty smell that’s sometimes associated with dried sea moss. The gel is then eaten by the spoonful once or twice a day, or mixed into a beverage like Erewhon’s strawberry skin smoothie, which was created by Hailey Bieber. There are also recipes on Pinterest for fruit-based “ice cream,” gummies, and jams made with sea moss.
Outside of its edible uses, gracilaria is a popular species of algae for indoor aquariums, and is sometimes found in skin care products like jelly face masks.
Is sea moss good for you?
In limited doses, it might be. Proponents claim that sea moss gel can improve heart health, help you lose weight, and lower cholesterol. The evidence for those purported benefits is pretty slim, but experts suggest that it can be a good supplemental (and vegetarian) source of essential vitamins and minerals. “Overall, there are nutritional benefits in consuming sea moss, with a little bit of science behind them,” says dietician-nutritionist Lorraine Kearney. “It contains copper, magnesium, zinc, and vitamins B, B6, and B9.” It’s also a source of iodine, which can be good for people who lack dietary sources of iodine, like shrimp and iodized salt.
But there isn’t much scientific research on the efficacy of sea moss gel. “While there may be some benefits in sea moss, it’s not something that is FDA regulated,” says Dr. Selvi Rajagopal, an assistant professor of medicine at Johns Hopkins University. “When something isn’t FDA regulated, it means that there likely haven’t been large-scale randomized control trials, which are the gold standard for this type of research. There are some studies out there, but the evidence is sort of sparse right now.”
What are the risks in eating sea moss gel?
Consuming too much sea moss gel could increase the risk of iodine toxicity: Iodine is an essential nutrient, but in excessive doses, it can be dangerous. “With iodine toxicity, the concern is that you could have thyroid dysfunction, thyroid cancer, and gastrointestinal symptoms,” Rajapagol says. “It can also be hard to quantify exactly how much iodine you’re getting in a ‘dose’ of sea moss because it’s not an FDA regulated product.” Even though it is sometimes touted as a fertility supplement, Kearney advises that people who are looking to become pregnant or are currently breastfeeding should not consume sea moss gel, in part because of the risk of elevated iodine levels.
Also at issue is the risk of heavy metal toxicity. Our oceans are heavily polluted, and high levels of mercury, lead, and cadmium, along with industrial chemicals, have been found in algae. “Sea moss is grown under various conditions, and we know that it can absorb heavy metals from its environment,” Noel says. “These metals can accumulate in the body over time, to the point where it can become toxic in someone who is ingesting sea moss on a regular basis.”
So, should I be adding sea moss to my smoothies?
Not necessarily. In small, infrequent doses — a couple of times a week in a smoothie — it’s likely that sea moss gel wouldn’t be harmful. But it’s definitely not a nutritional panacea, and could have some negative impacts if you have certain health conditions or are trying to get pregnant.
It’s also important to have a conversation with your doctor before taking sea moss — or any other supplement — to ensure that it’s compatible with your specific health concerns. “In that case, if you think this might help you, then fine,” says Rajagopal. “But it should probably be with the knowledge of your doctor and under monitoring so that you can see whether or not your deficiencies are actually improving.”