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Head-to-head evidence comparison — which supplement is right for you?
Glucomannan and Iodine are closely matched across evidence, studies, and safety.
Verdict
Likely helps
12 of 13 studies with measurable effects showed benefit.
Top outcomes
Verdict
Mixed evidence
4 of 12 studies with measurable effects showed benefit.
Top outcomes
1g three times daily before meals (3g total)
30-60 minutes before meals, With 1-2 glasses of water, Before largest meals for weight loss
Capsules (safest)
150-300mcg for maintenance; higher only if deficient under supervision
Any time with food
Potassium iodide (most common and studied)
30-60 minutes
4-8 weeks
4-8 weeks
If improperly taken
4-12 weeks
4-8 weeks
Effect of glucomannan on plasma lipid and glucose concentrations, body weight, and blood pressure: systematic review and meta-analysis
The American journal of clinical nutrition (2008) · Meta analysis · n=531
Glucomannan appears to beneficially affect total cholesterol, LDL cholesterol, triglycerides, body weight, and FBG, but not HDL cholesterol or BP.
The Impact of Glucomannan, Inulin, and Psyllium Supplementation (Soloways(TM)) on Weight Loss in Adults with FTO, LEP, LEPR, and MC4R Polymorphisms: A Randomized, Double-Blind, Placebo-Controlled Trial
Nutrients (2024) · Rct · n=112
The experimental group showed significant reductions in body weight (treatment difference: -4.9%; 95% CI: -6.9% to -2.9%; p < 0.01) and BMI (treatment difference: -1.4 kg/m2; 95% CI: -1.7 to -1.2; p < 0.01) compared to placebo.
Comparative effects of nutraceuticals on body weight in adults with overweight or obesity: A systematic review and network meta-analysis of 111 randomized clinical trials
Pharmacological research (2023) · Meta analysis · n=6171
We conducted random-effects network meta-analysis with a Frequentist framework to estimate mean difference [MD] and 95% confidence interval [CI] of the effect of nutraceuticals on weight loss.
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.
Meta-analysis of 6 RCTs (n=225) showed modest but significant weight reduction vs placebo. Effects appear greater in females. Limited long-term data available.
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.
AI-estimated from published studies. Interpret as directional guidance.
Both Glucomannan and Iodine are closely matched — the best choice depends on your specific health goals.
For boost daily energy, Iodine has a higher relevance score (95 vs 80).
No known interactions between Glucomannan and Iodine have been documented in our database. However, always consult a healthcare provider before combining supplements.