No less than seven people have mentioned sea moss or sea moss gel to me in the past couple of weeks, so I knew I had to look into it. The kicker? Each person said they heard it was good for different health concerns. This always gives me pause, but the ingredient is clearly having a moment: The #seamoss hashtag clocks in over 272 million views on TikTok.
As with many health and beauty trends, sea moss isn’t new. In 2020, even Kim Kardashian tweeted that she’s a fan of sea moss smoothies—though it’s been around longer than that. In fact, you may already be using or consuming it in your daily life without even knowing it. So, what exactly is it and should you be seeking out this ingredient for your next smoothie or face mask? We asked both a dermatologist and registered dietitian to share what the science says about sea moss.
What is Sea Moss?
Sea moss is an edible red seaweed found on rocky shores in the Northern Atlantic. While sea moss is the of-the-moment moniker, it’s also known as Irish moss, or its scientific name, Chondrus crispus. You may have heard of it more commonly called carrageenan.
Carrageenan is an extract from certain red seaweeds, primarily Chondrus crispus, that has been used as a thickening agent and emulsifier in food and beauty products for decades. These are just a few places you may spot carrageenan on a label:
- Nut milks
- Ice cream
- Processed meats
- Vegan or plant-based cheeses
- Facial serums
- Gel creams
So, if you’re consuming or using any of the above products, you’ve likely already come into contact with sea moss.
Is Sea Moss Safe?
Carrageenan derived from sea moss may be safely used in food, according to the United States Food and Drug Administration (FDA).
Some research has pointed to carrageenan’s detrimental effects on the G.I. tract in animals as a reason to pull it from human diets, but other research has found that it may have benefits. A 2018 review of the available research on carrageenan found that there is not enough conclusive evidence on either side of the argument and more research is needed.
One thing to note about the FDA’s approval of carrageenan as a food additive is that they generally assume you’re eating it in small amounts (only a little bit is needed to help make your plant-based yogurt taste creamy!) That doesn’t mean they’re okaying you to dive into a jar with a spoon daily, like some users are doing on TikTok.
“Sea moss gel is generally safe to consume since it is a type of seaweed, which is safe,” says Jennifer Martin-Biggers, PhD, RD, HUM’s VP of scientific affairs and education. “However, seaweed is known to be prone to high heavy metal levels if grown in areas that do not control for environmental pollution.”
As for topical applications, the Environmental Working Group rates carrageenan as “Good,” and the ingredient scores low for common concerns like cancer, allergies, and immunotoxicity.
Sea Moss Benefits
There are many health benefits to seaweed, in general, and seaweed for skin has also become more popular. For its small size, seaweed is packed with vitamins and nutrients like iodine, iron, calcium, potassium, and antioxidants.
These are a few potential benefits that are specific to sea moss:
1. It’s Nutrient-Dense
Like other seaweeds, Irish moss packs vitamins and minerals into a small package. A 2-tablespoon serving of raw sea moss contains:
- 18.2 micrograms folate, 5 percent of the Daily Value
- .89 milligrams iron, 5 percent of the Daily Value
- 0.047 milligrams riboflavin, 4 percent of the Daily Value
- 14.4 milligrams magnesium, 3 percent of the Daily Value
- 47 milligrams iodine
- Trace amounts of zinc and copper
“While we know the nutritional profile of seaweed and it is generally healthy, most of the research on the health benefits of seaweeds comes from epidemiologic studies that evaluate associations between what people typically eat in their diets and if they develop disease over time,” explains Martin-Biggers. “There is a need for intervention studies (where people are given seaweed to consume compared to a placebo) to confirm the health benefits that are hinted at in experimental studies and the epidemiologic data.”
2. It Helps Skincare Products Absorb Better
“In one study, carrageenan has been shown to enhance absorption by acting as a vehicle for active ingredients,” says Hysem Eldik, MD, a dermatologist at Marmur Medical in New York City. “This allows for more product to permeate through the skin when it is combined with carrageenan versus if the ingredient was used alone,” he explains. “It has also been studied to act as a scaffolding for healing properties and applied to wounds allowing for absorption and penetration into the wound.”
3. It’s Hydrating
Dr. Eldik says sea moss can be particularly beneficial for people with dry skin, as it has a net moisturizing effect and has emulsifying and gelatinous properties. As a topical, sea moss has some winning properties.
4. It May Support Immunity
As for the claims on TikTok about sea moss boosting your immunity, Martin-Biggers says they may be true. “There are some preliminary studies in animals that show promising effects,” says Martin-Biggers. For instance, one study found salmon that consume sea moss show benefits to their immune response. Still, more evidence is needed in humans to confirm this benefit.
Sea Moss Side Effects
Just like the benefits, the potential side effects depend a lot on whether you’re consuming sea moss or using it as a topical.
Some TikTok users have reported stomach issues after consuming sea moss gel, which tbh, might just be because they’re eating jelly that tastes like seaweed? Jury is still out.
But Dr. Elkin notes, “Ingestion of carrageenan has shown to be correlated with inflammation in the gastrointestinal tract.” Hence, he advises that those with inflammatory skin conditions such as eczema, psoriasis, and rosacea steer clear.
Also—while it would be pretty hard to eat *this* much sea moss, because seaweed is rich in iodine, one study found that eating 286 grams a day would put you above the upper limit for iodine. As a result, “Consuming too much can provide an excess of iodine which can be detrimental to your thyroid (iodine-induced hyperthyroidism),” says Martin-Biggers.
“Overall, it’s not necessary to consume [sea moss] for your health,” says Martin-Biggers. “I recommend focusing instead on improving your overall diet, and if you are looking for additional benefits, incorporating supplements that are more proven in research in humans to have benefits on your skin, immune system, and more.”
Though, if you still want to try sea moss, “Don’t take more than is recommended on the instructions or more than four grams per day,” she says. Martin-Biggers also recommends looking for reputable sources of sea moss.
For skin benefits, you may want to try topical products containing sea moss and its extract, carrageenan, such as: