Loading…
We use essential cookies (authentication, your saved goals/stack) by default. With your permission we’ll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more about cookies
Head-to-head evidence comparison — which supplement is right for you?
Biotin vs Iodine: Iodine has the stronger overall evidence (8.5 vs 5/10); they're alternatives for prenatal support — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Iodine wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Too few graded studies
1 of 1 studies with measurable effects showed benefit.
Top outcomes
Verdict
Limited support
1 of 4 studies with measurable effects showed benefit.
Top outcomes
2500-5000mcg (2.5-5mg) for hair/nails
Any time of day
Biotin capsules or tablets
150-300mcg for maintenance; higher only if deficient under supervision
Any time with food
Potassium iodide (most common and studied)
and 2 more not shown
3-6 months
3-6 months
4-12 weeks
4-8 weeks
Quantitative comparison of the efficacy of clinical drug treatments for primary progressive multiple sclerosis
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia (2023) · Meta analysis · n=3779
Model-based meta-analysis of 15 studies in 3,779 patients with primary progressive multiple sclerosis, 9 placebo-controlled and 6 single-arm, covering 12 drugs.
Vitamin supplementation in the treatment of optic neuritis: A systematic review and meta-analysis
Multiple sclerosis and related disorders (2025) · Meta analysis
The effect of MD1003 (high-dose biotin), vitamin A, and vitamin D on retinal nerve fiber layer (RNFL) thickness from pooled results showed a mean change of 0.15 (SMD 0.15, 95 % CI, -0.33 to 0.64, I2 = 61 %, τ² = 0.11, p = 0.08), which was not significant.
High-dose biotin for multiple sclerosis: A systematic review and meta-analyses of randomized controlled trials
Multiple sclerosis and related disorders (2021) · Meta analysis · n=889
Pooled data for ITW25 at 12 to 15 months yielded statistical significance (RR 2.06; 95% CI 1.04-4.09; 2 trials; 796 participants; I2 = 0%) [moderate COE] favoring HDB among patients with PMS.
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.
Iodine has a higher evidence score (8.5/10 vs 5/10) and wins in 2 of 3 categories.
For prenatal support, Iodine has a higher relevance score (80 vs 50).
No documented interaction was found in the data searched. This does not establish that this exact combination is safe.
The proven options (minoxidil, finasteride) vs adjuncts and weak naturals — tiered for pattern hair loss.
Selenium helps; iodine can WORSEN Hashimoto’s. The honest take on "thyroid support".
What’s safe while nursing, the truth about milk-supply herbs, and what to avoid (it passes into milk).
Commonly recommended vs ask-your-clinician vs avoid — a general, safety-first overview.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.