No abstract

Ginger (Zingiber officinale) is often advocated as beneficial for nausea and vomiting. Whether the herb is truly efficacious for this condition is, however, still a matter of debate. We have performed a systematic review of the evidence from randomized controlled trials for or against the efficacy of ginger for nausea and vomiting. Six studies met all inclusion criteria and were reviewed. Three on postoperative nausea and vomiting were identified and two of these suggested that ginger was superior to placebo and equally effective as metoclopramide. The pooled absolute risk reduction for the incidence of postoperative nausea, however, indicated a non-significant difference between the ginger and placebo groups for ginger 1 g taken before operation (absolute risk reduction 0.052 (95% confidence interval -0.082 to 0.186)). One study was found for each of the following conditions: seasickness, morning sickness and chemotherapy-induced nausea. These studies collectively favoured ginger over placebo.

The evidence for most dietary supplements as aids in reducing body weight is not convincing. None of the reviewed dietary supplements can be recommended for over-the-counter use.

Based on these data, it is concluded that the efficacy of ginseng root extract is not established beyond reasonable doubt for any of these indications. The widespread use of ginseng as a herbal remedy warrants more rigorous investigations to assess its efficacy and safety.

The benefit of yohimbine medication for erectile dysfunction seems to outweigh its risks. Therefore, yohimbine is believed to be a reasonable therapeutic option for erectile dysfunction that should be considered as initial pharmacological intervention.