| Effect | Decrease |
| Values | Percentage reduction in symptoms from complaint index. Mean and 95% CI. Doctor's evaluation: Per protocol. Visit 3: Low dose: 62.7% ± 11% High dose: 64.3 % ± 12% Root only: 44.8%:= 20% Placebo: 29.3% := 18%. ITT. Low dose: 58.7% := 10% High dose: 58.1 %±11 % Root only: 46.1 % ±16% Placebo: 33.6 %:= 17%. Patient's records. Per protocol: Low dose: 50.6% ± 11% High dose: 55.9% ± 9% Root only: 35.2% ±17% Placebo: 37.0% ± 13%. ITT: Low dose: 43.6 % ± 11% High dose: 52.0 %:!: 8% Root only: 35.8%:!: 13% Placebo: 33.2% ± 13% |
| Trial Design | Randomized trial |
| Trial Length | n/a |
| Number of Subjects | 246 |
| Sex | Both Genders |
In a randomized, double-blind, placebo-controlled trial, 246 of 559 recruited participants caught a common cold and took two capsules 3 times daily of 6.78 mg of an echinacea purpurea crude extract based on 95% herb and 5% root, 48.27 mg of that same extract, 29.60 mg based on root only, or placebo.Funding issues for this study:
65 of the 246 participants were excluded from the per-protocol analysis due to dropouts and protocol violations but were included in the intention to treat analysis. The primary outcome was the reduction in cold symptoms according to doctors' records, and participants in each group saw notably greater reductions in average symptoms than placebo, with there not being a notable difference between per protocol and intention to treat. Root + herb extracts were equally effective despite their different dosing, while the root only extra, while more effective than the placebo, was less effective than root + herb. However, there were no differences between the root only extra and placebo from patients' records, while root + herb appeared to be effective.
Funding source not specified.
