The first comprehensive review of herbal supplements for weight loss in almost two decades shows insufficient evidence to recommend any as treatments, say Australian researchers.

The University of Sydney investigators included 54 randomised controlled trials comparing the effect of herbal medicines with placebo for weight loss in more than 4000 participants.

Even though many of the herbal medicines showed statistically significant greater weight loss than placebo, this was less than 2.5kg and therefore not of clinical significance, the authors wrote.

“Currently there is insufficient evidence to recommend any of these herbal medicines for weight loss,” said the authors, led by Dr Nick Fuller (PhD) of the university’s Boden Collaboration for Obesity, Nutrition, Exercise and Eating Disorders.