Key studies of efficacy

Systematic reviews Linde K, Ramirez G, Mulrow CD, Pauls A, Weidenhammer W. St John's wort for depression—an overview and meta-analysis of randomised clinical trials. BMJ 1996;313:253-258 Melchart D, Linde K, Fischer P, Kaesmayr J. Echinacea for preventing and treating the common cold. Cochrane Library. Issue 3. Oxford, UK: Update Software, 1999 Wilt TJ, Ishani A, Stark G, MacDonald R, Lau J, Mulrow C. Saw palmetto extracts for treatment of benign prostatic hyperplasia: a systematic review. JAMA 1998;280:1604-1609 Randomized controlled trials Sheehan MP, Rustin MH, Atherton DJ, et al. Efficacy of traditional Chinese herbal therapy in adult atopic dermatitis. Lancet 1992;340:13-17