About Echinacea
Echinacea is a widely used immune-support herb. ERA-PRIMA 2024 meta-analysis (30 RCTs, n=5652) found 25–32% reduced respiratory infection risk and 40% reduced antibiotic use. Shah 2007 meta-analysis (14 studies) found 58% reduced odds of catching a cold and 1.4 days shorter duration. However, the Cochrane Review 2014 (24 trials, n=4631) found only 'possible weak benefit' and questioned clinical relevance. Heterogeneity in preparations (species, plant part, extraction method) explains inconsistent results. E. purpurea hydroalcoholic extracts standardized to alkylamides or cichoric acid have the strongest evidence. No established RDA/UL.
What Echinacea supports
- May reduce cold incidence by 25–58% (meta-analyses vary)
- May shorten cold duration by ~1 day
How much Echinacea to take
The RDA prevents deficiency. The effective range is what clinical trials used to actually move the outcome.
Effective
300–1500
mg
Prevention: 300–500 mg/day standardized extract. Acute treatment: 900–1500 mg/day at cold onset.
Clinical evidence
Moderate clinical evidence. Meta-analyses of 14-30 trials show 25-58% reduced cold risk, but Cochrane found only 'possible weak benefit'
Examine.com