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Head-to-head evidence comparison — which supplement is right for you?
Echinacea wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Probably helps
6 of 11 studies with measurable effects showed benefit.
Top outcomes
Verdict
Mixed evidence
4 of 11 studies with measurable effects showed benefit.
Top outcomes
300-500mg extract 3x daily at first symptoms, OR 2.5ml tincture 3x daily
At first sign of symptoms, Multiple times daily during illness
Standardized extract (4% echinacosides or standardized alkylamides)
150-300mcg for maintenance; higher only if deficient under supervision
Any time with food
Potassium iodide (most common and studied)
With continuous use
When taken at onset
4-12 weeks
4-8 weeks
Identifying immunostimulatory herbal supplements that may flare autoimmune skin diseases: a systematic scoping review
Lupus science & medicine (2025) · Systematic review · n=469
We identified 227 herbal supplements with immunostimulatory properties, of which 15 were most strongly supported by the evidence.
Echinacea Supplementation Does Not Impact Aerobic Capacity and Erythropoiesis in Athletes: A Meta-Analysis
Nutrients (2024) · Meta analysis · n=107
There was also no statistically significant change in erythropoietin (effect size -0.29, p = 0.05, 95% CI -0.75-0.17, I2 = 67%) or maximal oxygen uptake (effect size -0.20, p = 0.95, 95% CI -0.60-0.21, I2 = 0%).
Select Dietary Supplement Ingredients for Preserving and Protecting the Immune System in Healthy Individuals: A Systematic Review
Nutrients (2022) · Systematic review
Immune health products represent approximately 10% of all US dietary supplement sales.
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.
Based on meta-analyses showing modest SMD of -0.19. Significant heterogeneity between products tested. Evidence stronger for E. purpurea aerial parts preparations.
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.
Echinacea has a higher evidence score (9/10 vs 9/10) and wins in 2 of 3 categories.
No known interactions between Echinacea and Iodine have been documented in our database. However, always consult a healthcare provider before combining supplements.