Chondrus crispus Stackhouse · food
Evidence tier: insufficient
Sea moss is Chondrus crispus, a red seaweed from rocky Atlantic shores. It is a sea vegetable with a long history in Caribbean and Irish kitchens, and is sold as a gel, as dried seaweed or in capsules.
No benefit mechanism is established in people. The one well established route into the body is iodine acting on the thyroid, which is a risk route as much as a benefit: too much iodine can push the thyroid either way (OPSS).
There is essentially no human evidence for sea moss. OPSS says human clinical research to test its claims is lacking, and LactMed says no medicinal value has been proven. What it does have is iodine, in amounts nobody can predict from the label: a test of 96 seaweed products found iodine from 128 to 62,400 micrograms per portion and supplements from 5 to 5,600 micrograms, with 54 products over the safe upper level in a single portion and labels judged inadequate (PMID 33889064). Seaweeds can also carry arsenic, lead, cadmium and mercury (LactMed; OPSS).
No evidence based dose exists. The number that matters is iodine per serving: adults need about 140 micrograms a day, and 0.5 mg (500 micrograms) or less a day from supplements is unlikely to cause harm (NHS). Most sea moss labels do not state iodine.
Pick a product that lists iodine per serving and has heavy metal testing. Do not combine with kelp, bladderwrack or iodine supplements. Talk to your doctor first if you have a thyroid condition or take thyroid medicine [OPSS].
Sea moss and bladderwrack are seaweeds, and seaweed carries iodine. The amount varies a lot, and it is not something a label can tell you reliably. If you have a thyroid condition, take thyroid medication, or have Hashimoto's, do not take this without talking to your doctor first. Do not take it if you are pregnant or breastfeeding.
Pregnancy: avoid
Breastfeeding: avoid
Active compounds: carrageenan (sulfated polysaccharide), iodine, polyphenols including gallic acid and chlorogenic acid, minerals including calcium, iron, manganese, zinc
Remedies using Sea Moss · Browse by body system · Check it against what you take
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.