A study that claims to show that a homeopathic treatment can ease pain in rats has caused uproar after it was published in a peer-reviewed journal. Groups that promote homeopathy in Italy, where there is currently a debate about how to label homeopathic remedies, have held the study up as evidence that the practice works. But several researchers have cast doubt on its claims. The authors acknowledge some errors ... but stand by its overall conclusions. This latest claim has attracted attention, in part, because it passed peer review at the journal Scientific Reports. "Either the paper is true, so it's of extraordinary importance, or it's false and should be closely scrutinized," says Enrico Bucci, the researcher who carried out [an] analysis of the paper. Homeopathy is based on the claim that illnesses can be treated using substances that produce similar symptoms. Mostly, these have been heavily diluted in water or alcohol so that none or only a few molecules of the active ingredient are present. Some supporters of the practice say that the water or alcohol 'remembers' the substance, which triggers a healing response. In the ... study, Patil and colleagues report that a homeopathic product - a heavily diluted extract from Toxicodendron pubescens, a plant commonly known as Atlantic poison oak - is as effective as the prescription drug gabapentin in reducing inflammation and pain responses in both cells grown in the lab and in animals.