aka " Purple Cornflower"

3 species: E. purpurea, E. pallida, E. angustifolia

FOR PREVENTION OF viral upper respiratory infections (URIs):

289 healthy pts treated with echinacea (2 groups for 2 diff. preparations, each from the root of wither E. angustifolio or E. purpurea) vs. placebo BID x 12 wks. No sig. diff. between groups in #, severity, or duration of URI's during the f/u period. The E. angustifolia group had higher rate of adverse f/x, including GI sx,HA, and dizziness (Arch. Fam. Med. 7:541, 1998--JW)

430 children age 1-5yo randomized to a combination of (echicacea extract, propolis, and vitamin C) BID vs. placebo x 12wks during the winter. Active-tx group had RR 0.57 for URI and 55% fewer URI episode overall (Arch. Ped. Adol. Med. 158:217, 2004--JW)

No diff. in URI incidence in a randomized 8wk trial in 109 pts randomized to E. purpurea vs. placebo (Am. J. Med. 106:138, 1999--Med. Lett.)

No difference w. Echinacea vs. placebo in URI incidence in pts receiving an experimental rhinovirus challenge (Antimicrob. Agents. Chemother. 44:1708, 2000--Med. Lett.)

48 adults tx'd with echinacea TID x 7d before and after inoculation with rhinovirus. No sig. diff. in incidence of cold sx (Clin. Inf. Dis. 38:1367, 2004--JW)



Various small trials have shown benefit of Echinacea vs. placebo in decreasing severity and/or sx of URI's but have many methodoligic flaws (Med. Lett. 44:29, 2002)

Echinacea was ass'd with no diff. in duration or severity of sx in a randomized study of 148 college students with recent onset of URI sx (Ann. Int. Med. 137:939, 2002--JW)

Echinacea purpurea, vs. placebo, started at onset of sx for URI's (max 10d) was not ass'd with any sig. diff. in duration or severity of sx in a randomized tiral of 407 kids 2-11yo (JAMA 290:2824, 2003--abst)

Echinacea purpurea (freeze-dried extract of the above-ground parts) 100mg TID vs. placebo, in a randomized trial in 128 adults with cold sx of < 24h duration, continued until sx resolved (up to 14d), was not associated with any sig. diffs in sx scores at any time point (Arch. Int. Med. 164:1237, 2004--AFP)

In a study in 437 healthy young pts randomized to placebo or one of three echinacea angustifolia extracts for 7d prior to and 5d after experimental challenge with rhinovirus type 39, there was no sig. diff. in any clinical or biochemical measure of illness (NEJM 353:341, 2005--JW)