Potassium Iodide · Kelp Extract · Iodide
150 mcg · vegan · gluten-free · 180 caps
Affiliate link · we earn from qualifying purchases. No paid placements.
Iodine is an essential trace element required for thyroid hormone synthesis. The thyroid gland actively concentrates iodide via the sodium-iodide symporter (NIS) and incorporates it into thyroglobulin to produce thyroxine (T4) and triiodothyronine (T3). The RDA is 150 mcg/day for adults, 220 mcg during pregnancy, and 290 mcg during lactation.
Iodine is the rate-limiting substrate for thyroid hormone production. The thyroid follicular cells trap iodide, oxidize it via thyroid peroxidase (TPO), and organify it onto tyrosine residues within thyroglobulin. This forms monoiodotyrosine (MIT) and diiodotyrosine (DIT), which couple to form T4 and T3. The Wolff-Chaikoff effect describes the paradoxical inhibition of thyroid hormone synthesis that occurs with acute iodine excess — a protective mechanism that can become pathological with chronic excess.
Individuals with confirmed iodine deficiency (urinary iodine <100 mcg/L) · pregnant women in iodine-deficient regions · vegans in areas without iodized salt · those with goiter in endemic deficiency areas · NOT for general supplementation in iodine-sufficient populations.
Hashimoto's thyroiditis or any autoimmune thyroid disease · hyperthyroidism/Graves' disease · thyroid nodules · dermatitis herpetiformis (Duhring's disease) · concurrent use with antithyroid medications · high-dose kelp supplements (>500 mcg iodine).
✓ Morning with breakfast
✓ Take with food to minimize gastric irritation
Iodine is the rate-limiting substrate for thyroid hormone production.
Each bar = one cited trial. Effect varies by methodology, dose, and population.
Subclinical hypothyroidism cohort (n≈60)
Target range 0.45–4.5 mIU/L. Individual results vary.
see study
→ Review of global data: both iodine deficiency and excess increase thyroid disorders. Autoimmune thyroiditis (Hashimoto's) incidence rises with iodine excess, particularly in genetically susceptible populations.
see study
→ Cross-sectional study across regions with different iodine intakes: overt hypothyroidism and autoimmune thyroiditis increased significantly in areas with excessive iodine intake (>300 mcg/day) compared with adequate intake.
see study
→ Systematic review: iodine supplementation in euthyroid adults with adequate baseline intake had no benefit and increased risk of subclinical hypothyroidism and elevated thyroid antibodies.
B · B for treating confirmed iodine deficiency (well-established, prevents cretinism and goiter). D for general population supplementation — most Western populations are iodine-sufficient and excess iodine triggers or worsens Hashimoto's thyroiditis. The dose-response curve is U-shaped: both deficiency and excess cause disease.
A plain-English read of the literature behind this supplement. Not a clinical recommendation.
Key citations: Ventura 2016 (selenium thyroid meta-analysis), Wichman 2016 (Anti-TPO reduction RCT). richResearch section contains study filters.
How to use Iodine specifically for Goiter — the right dose, timing, blood markers to track, and how to know if it is working.
A clinical evidence review of Iodine — RCT data, effect sizes, evidence grade, and what the numbers mean for your specific situation.
Everything you need to know about Iodine — mechanism, dose, safety, buying guide for India, and what the research actually says.
SacredBod's longer take on Iodine — context the structured blocks above don't capture.
Iodine is the clearest example of a U-shaped dose-response curve in nutrition: deficiency causes goiter, cretinism, and hypothyroidism; excess causes Hashimoto’s thyroiditis, hyperthyroidism, and thyroid dysfunction. The supplement industry sells high-dose kelp and iodine products as “thyroid support” with little regard for the well-documented risks on the right side of that curve.
The mechanism is thyroid-specific and tightly regulated. The sodium-iodide symporter (NIS) actively concentrates iodide into thyroid follicular cells, where thyroid peroxidase (TPO) oxidizes and organifies it onto thyrosine residues. This is the rate-limiting step in T4 and T3 synthesis. The Wolff-Chaikoff effect is an acute protective mechanism: when intrathyroidal iodine exceeds a threshold, hormone synthesis is temporarily inhibited. In most people, this resolves within days via the “escape” phenomenon. In susceptible individuals — particularly those with underlying thyroid autoimmunity — chronic excess prevents escape and leads to hypothyroidism or triggers autoimmune destruction.
The epidemiological evidence is consistent across continents. Laurberg et al. (2010) reviewed global data and found that both ends of the iodine spectrum increase thyroid disorders. Autoimmune thyroiditis incidence rose after iodine fortification programs in Zimbabwe, Denmark, and Greece — all in genetically susceptible populations. Teng et al. (2006) studied three Chinese regions with different iodine intakes: areas with excessive iodine (>300 mcg/day) had significantly higher rates of overt hypothyroidism, subclinical hypothyroidism, and autoimmune thyroiditis compared with adequate-intake areas.
The supplementation evidence in already-sufficient individuals is sobering. A systematic review (Zimmermann and Boelaert, 2012) found that iodine supplementation in euthyroid adults with adequate baseline intake provided no benefit and increased the risk of subclinical hypothyroidism and elevated thyroid peroxidase antibodies. The mechanism is the Wolff-Chaikoff effect without escape, combined with increased immunogenicity of highly iodinated thyroglobulin.
The honest framing: most people in iodine-sufficient countries do not need iodine supplements. The RDA of 150 mcg/day is easily met by iodized salt (1/4 teaspoon provides ~150 mcg), dairy products, eggs, and seafood. High-dose kelp supplements are particularly dangerous because kelp iodine content varies by 10-100x between batches, and doses of 1,000-2,000 mcg are common. This is 7-13x the RDA and well into the excess range that triggers autoimmunity.
Practical guidance: do not supplement iodine without a urinary iodine concentration test or documented deficiency. If deficient, 150 mcg/day is sufficient. Pregnant women need 220 mcg/day — prenatal vitamins typically contain this amount. If you have thyroid antibodies (TPOAb or TgAb), avoid iodine supplements entirely. If you take kelp, know that you are taking an unstandardized, variable-dose product with genuine risk.
Peptides are physician-only. Tell us a bit and we'll route you to the right specialist.
