Best Iodine Supplements 2026: Cost per Effective Dose
Top pick for Iodine: Nutricost Kelp Tablets, 325mcg Iodine — 325mcg per 1 tablet, None stated, $0.05/day. Our best-value pick.
Registry check · Iodine
Does anyone independently verify Iodine supplements?
We could not confirm a single one of these 6 products in any registry, and none of them claims otherwise. Not one brand here displays a certification mark, so on independent verification all 6 start level.
6 checked against all 5,317 US NSF, USP and Informed Sport listings, 2026-08-25. Full method and limitations.
What 4 Iodine labels show
Priced per day, these iodine products run $0.04 to $0.11 — a 2.8× gap between the cheapest and dearest iodine here, across 3 brands.
Which row that favours is not obvious: NOW Foods NOW Supplements Kelp, 150mcg Natural Iodine is cheapest per serving at $0.04, but its serving sits below the median here, so part of that price gap is simply a smaller capsule.
All Iodine Supplements Compared
| Product | Brand | Dose / Serving | Cost / Day | Certification (as labelled) | Pick | Buy |
|---|---|---|---|---|---|---|
| NOW Supplements Kelp, 150mcg Natural Iodine | NOW Foods | 150mcg / 1 tablet | $0.04 | None stated | Buy | |
| NOW Supplements Kelp, 325mcg Natural Iodine | NOW Foods | 325mcg / 1 veg capsule | $0.05 | None stated | Buy | |
| Nutricost Kelp Tablets, 325mcg Iodine | Nutricost | 325mcg / 1 tablet | $0.05 | None stated | Best Value | Buy |
| Life Extension Sea-Iodine, 1000mcg | Life Extension | 1000mcg / 1 veg capsule | $0.11 | None stated | Buy |
In-Depth Iodine Guides
Go deeper on iodine — by goal, by form, and what the evidence actually supports:
Our Picks
Best Value: Nutricost Kelp Tablets, 325mcg Iodine
325mcg per 1 tablet. None stated. $0.05/day. 240 servings per container at $11.95.
The shelf · Iodine
These Iodine servings are not comparable to each other
NOW Supplements Kelp, 150mcg Natural Iodine states 150 mcg a serving and Nutricost Potassium Iodide (KI), 65mg states 65,000 mcg — both occupy one row of the same price column. So NOW Supplements Kelp, 150mcg Natural Iodine showing 4¢ a day, the lowest here, may be reporting a smaller serving rather than a better price. Before comparing NOW Supplements Kelp, 150mcg Natural Iodine with Optimox Iodoral 12.5mg, check what each calls a serving.
Method: the 6 Iodine products above, compared on label facts — serving size, servings per container, form, price. Not a dosing recommendation.
The evidence · Iodine
What the published reviews of Iodine concluded
- Chlorhexidine or Povidone-Iodine Solution Irrigation Versus Saline Irrigation for the Prevention of Postoperative Infections in Primary Total Joint Arthroplasty: A Systematic Review and Meta-Analysis. · The Journal of arthroplasty, 2025
“In this meta-analysis, chlorhexidine and povidone-iodine had a significantly reduced risk of PJI as compared with saline irrigation in total joint arthroplasty. There was no significant difference between chlorhexidine and povidone-iodine.”
- The Comparative Efficacy of Chlorhexidine Gluconate and Povidone-iodine Antiseptics for the Prevention of Infection in Clean Surgery: A Systematic Review and Network Meta-analysis. · Annals of surgery, 2021
“Alcoholic formulations of 4%-5% CHG seem to be safe and twice as effective as PVI (alcoholic or aqueous solutions) in preventing infection after clean surgery in adults.”
- Preoperative Antisepsis with Chlorhexidine Versus Povidone-Iodine for the Prevention of Surgical Site Infection: a Systematic Review and Meta-analysis. · World journal of surgery, 2020
“Chlorhexidine was superior to povidone-iodine in preventing postoperative SSI, especially for the clean-contaminated surgery. However, there was no statistically significant difference in the incidence of skin adverse events between CH and PI groups.”
- Chlorhexidine vs Povidone-Iodine and Incidence of Catheter-Related Infections: A Systematic Review and Meta-Analysis. · JAMA network open, 2026
“In this NMA of RCTs, high concentration CHG in isopropyl alcohol was associated with the lowest incidence of CRIs. These results suggest that alcoholic PVI and aqueous formulations should be reserved for situations in which CHG or alcohol cannot be used.”
Method: PubMed searched in humans for systematic reviews and meta-analyses with Iodine in the title; these 4 of the 10 that qualified are shown with the authors’ own conclusion quoted rather than summarised. What it cannot tell you: whether Iodine will work for you — each of these reports an average across trials published 2020–2026, and null findings are shown here as readily as positive ones.
How these 4 Iodine products were ranked
Not one of these 4 iodine products could be confirmed in the NSF, USP or Informed Sport registries, so verification separates none of them and the ranking falls to cost per day at the labelled serving. Commission does not enter it: the rate is the same whichever iodine you buy. Full methodology.