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Head-to-head evidence comparison — which supplement is right for you?
Iodine wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Mixed evidence
4 of 12 studies with measurable effects showed benefit.
Top outcomes
Verdict
Probably helps
2 of 3 studies with measurable effects showed benefit.
Top outcomes
150-300mcg for maintenance; higher only if deficient under supervision
Any time with food
Potassium iodide (most common and studied)
2-3g
With meals, Split into 2-3 doses
Powder or capsules
4-12 weeks
4-8 weeks
4-12 weeks
2-4 weeks
8-12 weeks
Maternal Iodine Status and Birth Outcomes: A Systematic Literature Review and Meta-Analysis
Nutrients (2023) · Meta analysis · n=42269
Birth weight was similar between UIC ≥ 150 μg/L and <150 μg/L (difference = 30 g, 95% CI −22 to 83, p = 0.3, n = 13, I2 = 89%) with no evidence of linear trend (4 g per 50 μg/L, −3 to 10, p = 0.2, n = 12, I2 = 80%).
Iodine fortification of foods and condiments, other than salt, for preventing iodine deficiency disorders
The Cochrane database of systematic reviews (2019) · Meta analysis · n=4317
This is equivalent to an increase of 38.32 µg/L (95% CI 24.03 to 52.61 µg/L).
Systematic review and meta-analysis of iodine nutrition in modern vegan and vegetarian diets
The British journal of nutrition (2023) · Meta analysis · n=4421
Vegan diets had the poorest iodine intake (17·3 µg/d) and were strongly associated with lower iodine intake (P = < 0·001) compared with omnivorous diets.
Effects of dietary supplements on patients with osteoarthritis: A systematic review and network meta-analysis
Journal of integrative medicine (2025) · Meta analysis · n=2455
In the WOMAC pain score, the SUCRA of passion fruit peel extract was 91% (mean difference [MD]: -9.2; 95% confidence interval [CI]: [-16.0, -2.3]), followed by methylsulfonylmethane (89%), undenatured type II collagen (87%), collagen (84%), and Lanconone (82%).
Methylsulfonylmethane Improves Knee Quality of Life in Participants with Mild Knee Pain: A Randomized, Double-Blind, Placebo-Controlled Trial
Nutrients (2023) · Rct · n=88
The total scores at 12 weeks in the MSM and placebo groups as the primary outcome were significantly different (p = 0.046).
The Effect of Daily Methylsulfonylmethane (MSM) Consumption on High-Density Lipoprotein Cholesterol in Healthy Overweight and Obese Adults: A Randomized Controlled Trial
Nutrients (2021) · Rct · n=22
The primary finding of this work shows that high-density lipoprotein cholesterol was elevated at 8 and 16 weeks of daily MSM consumption compared to baseline, (p = 0.008, p = 0.013).
Based on meta-analyses showing urinary iodine concentration increases with supplementation. Effects only meaningful in iodine-deficient populations. Excessive intake (>300mcg) may increase thyroid cancer risk. Most studies used potassium iodide; kelp-derived forms have variable bioavailability.
Based on limited RCT evidence. One 12-week study (n=88) showed significant improvement in knee pain scores. Conservative effectiveness estimate given small study size and limited replication.
AI-estimated from published studies. Interpret as directional guidance.
Iodine has a higher evidence score (8.5/10 vs 6/10) and wins in 2 of 3 categories.
No known interactions between Iodine and MSM have been documented in our database. However, always consult a healthcare provider before combining supplements.