Key takeaways
Sea moss is a red alga harvested from the Atlantic Ocean that has been used as a food additive for many years; recent trends have put it into the supplement spotlight as a potentially beneficial source of nutrients for women, in particular.
Seaweed, like sea moss, is high in many nutrients, such as iodine, folate, calcium, and zinc. Some of these may help women with common health conditions such as thyroid problems and low libido.
Sea moss supplements could contain excessively high levels of iodine and possibly heavy metals like arsenic; pregnant women, people taking certain medications, and other vulnerable populations should avoid taking them or only use them with caution under the supervision of a healthcare provider.
You’ve probably eaten seaweed as part of your favorite sushi dish before or even snacked on a package of dried seaweed from the shelf of your local health food store. But if you’ve heard a few on-trend health influencers talking up the benefits of dietary sea moss and wondered if you missed something, you’re not alone: sea moss has been making the rounds in some nutritional health circles. Still, it hasn’t gone quite as mainstream as nori, the type of seaweed used most often in sushi and snack foods.
When people talk about eating sea moss, they’re usually referring to Irish sea moss, or Chondrus crispus, a red algae that grows along the Atlantic coast in North America and parts of Europe. The green sea vegetable is harvested and used as a food additive because it produces carrageenan, which is used as a thickening agent in foods like soups, gummies, and ice cream.
Some people, though—particularly women—have started adding sea moss to their diets as a powder or tablet supplement. Some even add sea moss gel to their smoothies! Why? Because the superfood contains a lot of nutrients, some of which are especially beneficial for women, like folate, calcium, and iodine. It may also boost your immune system, gut health, libido, and overall health.
Like many other nutritional supplements, sea moss hasn’t been well-researched, and its true benefits, if any, are still unknown. Here’s what the experts do know about sea moss: seven potential health benefits for women, who should avoid it, and how much to take if you decide to give it a try.
7 health benefits of sea moss for women
In general, consumable types of seaweed provide some basic benefits: they’re high in vitamins and essential minerals, low in calories, and full of prebiotics. Sea moss, part of the red algae family, also carries these benefits, along with some others that could be especially helpful to the female body.
1. High in nutrients
According to the U.S. Department of Agriculture (USDA), red algae like sea moss are rich in many different vitamins and minerals, including vitamin C, iron, vitamin A, magnesium, zinc, potassium, and iodine.
Irish sea moss, especially, is high in calcium, which is just one way it works extra hard for women, who have higher calcium needs than men. Another way it provides a nutritional boost for females is in the form of folate, which protects against anemia and some congenital disorders during pregnancy. Per the USDA, a typical portion of Irish sea moss contains 182 micrograms of folate, almost half of the daily recommended intake.
2. Immune function support
There isn’t a lot of evidence of sea moss’ immune system support in human studies, but a 2018 study on Atlantic salmon found that dietary seaweed stimulated the immune response and helped them fight infection. When you look at the nutrient profile of sea moss, this immune support makes sense: sea moss is high in vitamin C, which has been shown to play a role in improving disease prevention.
3. Gut health
Sea moss may contribute to gut health thanks to its prebiotic effects, as well as its high nutrient profile, high fiber content, and potential antimicrobial properties, according to Inna Melamed, Pharm.D., functional medicine practitioner and author of Digestive Reset.
One reason why sea moss might be an extra powerful source of prebiotics is its resistance to breaking down during the early part of the digestive process, reports a 2016 study. This allows more of its beneficial compounds to reach the gut, where it can correct gut bacteria imbalances.
4. Thyroid support
Women are more likely than men to have problems with their thyroid gland, so it’s especially important that they support their thyroid health as much as possible through their diet and lifestyle habits. One way women can do that is by maintaining healthy iodine levels. When you don’t get enough of this mineral, your thyroid-stimulating hormone (TSH) levels may rise too high, leading to hypothyroidism and other health problems.
Sea moss has a significant iodine content, which Kelsey Costa, MS, RDN, registered dietitian and science communications officer at Examine, says can be beneficial—but there’s a caveat.
“While small amounts of sea moss are generally safe, excessive consumption can lead to an overabundance of iodine, potentially causing thyroid issues such as hyperthyroidism or thyrotoxicosis,” Costa explains.
More research is needed to determine if sea moss really does provide any benefit in the form of iodine and thyroid health, and Costa says some people—like infants, pregnant women, and older adults—are at a higher risk of problems related to too much iodine. No matter what, she recommends consulting with a healthcare provider for medical advice on monitoring your iodine levels if you’re taking sea moss regularly.
5. Increased libido
This is very much a potential benefit at this point, says Costa, who notes that the research on sea moss’ effects on libido is currently limited and incomplete (some sources claim it has aphrodisiac properties, but there is no scientific evidence to support that).
That said, there are a few ways in which sea moss might support the hormone levels that play a role in the female libido. We’ve already touched on iodine’s benefits to the thyroid, including keeping TSH levels normal, and Costa says some studies have found that women with thyroid disorders often experience higher rates of sexual dysfunction. If iodine helps maintain thyroid function, it might boost the libido, too—but Costa notes that there are other ways to treat thyroid issues (and sexual dysfunction symptoms often improve with treatment).
Sea moss also contains zinc, a libido-friendly nutrient. Costa says a 2021 study suggests that zinc might support hormone levels and sexual function in postmenopausal women. Still, it’s worth noting that this is likely only helpful for women with an actual zinc deficiency.
Basically, neither iodine nor zinc have been officially linked to sexual function or libido in women, and we don’t know how much sea moss supplementation helps with these nutrient levels, either (but the possibility is there!).
6. Skincare and hair health
Dr. Melamed says sea moss is rich in nutrients, hydrating, and contains both antioxidant and anti-inflammatory properties, making it a good choice for an ingredient in beauty products. It’s often used in hair masks, she adds, and many of the women who take sea moss supplements are hoping to see improvements to their hair and nail growth, as well as their complexions.
The National Eczema Foundation points out that the polyphenols, or plant-based compounds in sea moss, may hold many of these benefits, as they’re frequently linked to reducing inflammation (a primary cause of eczema). Other studies suggest that the compounds found in seaweed could have anti-aging properties.
7. Heart health
Irish sea moss is high in soluble fiber, which has been linked to lower levels of LDL cholesterol (also known as “bad” cholesterol). Fiber can improve blood sugar control, support weight loss and weight management, and lower your risk of developing chronic conditions like heart disease. And because of its high antioxidant content, sea moss has a protective effect on cardiovascular health.
Can pregnant women take sea moss?
Although sea moss may have several benefits for women, says Dr. Melamed, pregnant women should not take sea moss as a supplement unless their healthcare provider has recommended it. This is because of the risk of consuming dangerously high amounts of iodine, she explains, as well as the risk of exposure to some heavy metals, like arsenic and mercury—which edible seaweeds, including sea moss, are potentially contaminated with, per a 2019 study.
Based on the long-standing recommendation that pregnant women consume limited amounts of seafood to avoid excess exposure to mercury, the same precautions should be taken with sea moss. If you’re considering taking it during pregnancy, talk to your healthcare provider first.
Sea moss side effects
Other than the risks to vulnerable populations, sea moss is probably safe to take in the recommended amounts. While it’s often touted as a supplement that has special benefits for women, it’s important to understand that it doesn’t appear to directly affect female hormones, per Dr. Melamed: “So far, there is no strong scientific evidence directly linking sea moss to significant changes in female hormone levels such as estrogen and progesterone.”
The biggest potential risk associated with sea moss comes from consuming too much iodine—which could cause thyroid inflammation, oral discomfort, and serious gastrointestinal distress—as well as the risk of heavy metal contamination. The U.S. Food & Drug Administration (FDA) doesn’t approve supplements before they’re sold to consumers, so manufacturers aren’t required to disclose all the ingredients or the ingredient amounts in any of their products; this could lead to you consuming something potentially harmful without knowing it.
The other possible side effect of sea moss is related to its use in cosmetic and beauty products. Some people who are allergic to sulfur or shellfish will have a reaction to products containing seaweed, so it’s important to use these products cautiously if you’re at risk of an allergic reaction.
Because the scientific data regarding the safe dose of sea moss and the potential for serious toxicity, extreme caution should be used when taking this supplement.
Does sea moss interfere with medications?
There isn’t a lot of information about interactions between sea moss and other supplements or medications, says Costa, but based on its nutrient profile, we can draw some conclusions about who should use sea moss with caution or not take it at all.
- People who consume a lot of iodine, either from taking other supplements with iodine or eating a lot of iodine-rich foods like seaweed, dairy, and seafood, should carefully monitor their overall intake when using sea moss, says Costa.
- People taking certain medications should consult their healthcare provider before using a sea moss supplement. Costa says this list includes:
- Pacerone (amiodarone), which has a high iodine content
- Medications for inflammatory bowel disease because iodine can worsen GI symptoms
- Medications for autoimmune diseases
- Thyroid medications, including Tapazole (methimazole) or Synthroid (levothyroxine)
- The effects of sea moss on blood clotting are unclear. People with blood clotting issues or on blood-thinning medications should be careful with sea moss. It contains vitamin K, which can affect how the medication works, Dr. Melamed says.
- Children, pregnant women, and breastfeeding mothers should all exercise caution, Dr. Melamed says, because we don’t have enough information about its safety for those populations.
Bottom line
Like many other supplements, sea moss hasn’t been well-studied. It is very important to understand that there aren’t many clinical trials in humans to refer to when considering the safety or dosing of sea moss. Many of the studies on sea moss were performed in rats and worms, so the data cannot necessarily be extrapolated to humans.
A 2020 study suggests that a daily intake of three to four grams of dried sea moss is likely safe for healthy adults. However, Costa says the exact amount that’s right for you will vary based on the iodine content in the sea moss, your age and health status, and any other supplements or medications you’re taking.
When you might start feeling the benefits of your daily dose of sea moss, it’s a good question without a clear answer. “Some anecdotal evidence suggests that people may start noticing improvements in their energy levels, digestion, and overall well-being within a few weeks,” says Costa, “but the limited research means there’s no definitive answer to how long it takes.”
It’s worth noting, per Costa, that people who are deficient in certain vitamins or minerals before taking sea moss may experience more noticeable changes in their health over time with consistent supplementation. Either way, you should always talk to a healthcare provider about any supplement you’re taking or planning to take so they can make sure it’s safe for you.
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