← All supplements

Sea moss

Supplement algae general nutritionskin & hair
Aka: Irish moss, Chondrus crispus
Brands seen in Singapore: True Sea Moss, Codeage, Swanson Vitamins, Vitamatic, Nutricost
Third-party tested: Codeage certifies other products with NSF Certified for Sport, but nothing for sea moss.Certification is granted per product, so check the tub you actually own. Not being listed is not the same as failing.
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
A red seaweed eaten as food; its known nutrient is iodine
Pros & cons
Pros
  • 4 g a day of the dried seaweed was judged no risk
  • Supplies iodine, essential for thyroid hormones
  • Not listed in HSA's prohibited/restricted annexes
Cons
  • Iodine content varies between samples
  • A case report links sea-moss to thyrotoxicosis
  • SG caps supplement iodine at 0.15 mg a day
Sources
  1. Environmental Science and Pollution Research International 2020 — Risk assessment of iodine intake from the consumption of red seaweeds (Palmaria palmata and Chondrus crispus), 30 samples · read 2026-08-27
    what it says
    “Irish moss (3.86 ± 1.49 mg/kg dry weight) has the highest average iodine content … The consumption of analyzed seaweeds (4 g/day) does not pose a health risk.”
  2. Journal of the Endocrine Society 2021 — “Fueling the Fire”: Irish Sea-Moss Resulting in Jod-Basedow Phenomenon in a Patient With Grave's Disease (case report) · read 2026-08-27
    what it says
    “Herbal supplements containing sea-moss have high iodine amount which may precipitate thyrotoxicosis in patients with underlying Grave's disease or autonomous thyroid nodules.”
  3. NIH ODS — Iodine, Fact Sheet for Health Professionals (“Updated: April 28, 2022”), Introduction + Table 1 RDAs + Table 3 ULs; read via the web.archive.org capture 20230529002645 because ods.od.nih.gov 403s direct fetches · read 2026-08-27
    what it says
    “Iodine is an essential component of the thyroid hormones thyroxine (T4) and triiodothyronine (T3) … Table 1 lists the current RDAs for iodine … 19+ years 150 mcg … Tolerable Upper Intake Levels (ULs) for Iodine … 1,100 mcg”
  4. NIH ODS — Iodine, Fact Sheet for Health Professionals (“Updated: April 28, 2022”), Iodine and Dietary Supplements / Daily Value footnote / Interactions with Medications; read via the web.archive.org capture 20230529002645 · read 2026-08-27
    what it says
    “Supplements containing kelp, a seaweed that contains iodine, are also available … The DV for iodine is 150 mcg for adults … Taking high doses of iodine with anti-thyroid medications can have an additive effect”
  5. HSA Singapore — Guidelines on Prohibited and Restricted Ingredients in HS and TM (Oct 2025), Annex A row 55 (Iodine); no row for Chondrus crispus, Laminaria, kelp or seaweed · read 2026-08-27
    what it says
    “Iodine … Restricted use in HS and TM … When for oral use by general adult population, the maximum recommended daily dose should not provide more than 0.15mg”
  6. HSA Singapore — Health Supplements Guidelines (Jan 2026), clause 4.8 + Table 5: Minerals Limits · read 2026-08-27
    what it says
    “HS for use by the general adult population should not contain vitamins and minerals exceeding the stipulated limits stated in Tables 4 and 5 … Table 5: Minerals Limits … Iodine 0.15 mg”
  7. HSA Singapore — Guidelines on Prohibited and Restricted Ingredients in HS and TM, GL-CHPB-1-012 Rev. No. 001 (Oct 2025), Annex A (118 rows, Abrus to Zinc) and Annex B — both searched, no row for this ingredient · read 2026-08-27
    what it says
    “A list of specific prohibited and restricted ingredients is provided in Annex A … This list is not exhaustive. Dealers are responsible to ensure that their products are safe and appropriate for the target consumers.”
  8. iHerb Singapore — Sea Moss category, default (best-selling) order · read 2026-08-27
    what it says
    “1 - 48 of 62 results … True Sea Moss, Sea Moss Gel Superfood, Mango and Pineapple … Codeage, Sea Moss, Wildcrafted … Swanson Vitamins, Full Spectrum® Irish Moss, 400 mg … Vitamatic, Vegan Sea Moss Gummies … Nutricost, Organic Irish Sea Moss Powder”
Report a correction View as JSON

Updated 2026-08-30. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.