The placebo effect and randomized trials: analysis of conventional medicine.

Randomized controlled trials are generally regarded as the gold standard of study designs to determine causality. The inclusion of a placebo group in these trials, when appropriate, is critical to access the efficacy of a drug or supplement. The placebo response itself has received some attention in the medical literature over the past fifty years. The recent increasing utilization of dietary supplements and herbal medications by patients makes it imperative to reevaluate the placebo response in conventional and alternative medicine. This article will review a whole series of unique conditions (allergies/asthma, alopecia, BPH, erectile dysfunction, osteoporosis, weight loss...) and the placebo response associated with them from conventional medical randomized trials.