The effectiveness of popular, non-prescription weight loss supplements

Objectives: To review the evidence for the effectiveness of popular, non-pr escription weight loss supplements. Data sources: A detailed literature search including all relevant medical a nd supplementary medicine databases and evidence submitted from manufacture rs. Data synthesis: The theoretical basis and rationale for the use of each sub stance is considered along with available research in the published literat ure on effectiveness and potential risks. We classified the level of eviden ce represented by the main research studies on each substance. Conclusions: There is no good evidence for any weight loss benefits from mo st of the substances reviewed here. There is some support for mild effects of capsaicin, caffeine and fibre, but only in whole foods. In some cases le g, chitosan), there is a plausible theoretical basis for the product, but n o supporting proof of effect in humans in the absence of a calorie-controll ed diet. Possible synergistic effects of different ingredients cannot be di smissed, but cannot be assessed from current data. There is an absence of g ood quality research on many substances, which means that advertising claim s may be misleading.