The evidence for homeopathy

"To conclude that homeopathy lacks clinical effect, more than 90% of the available clinical trials had to be disregarded"       

Prof Robert Hahn, Homeopathy: Meta-Analyses of Pooled Clinical Data, 2013 

Some critics of homeopathy claim that there is a lack of evidence to support its effectiveness. In fact, there is a growing body of scientific research showing that homeopathy has a positive effect. This section of the website looks at some of the ways in which evidence for the positive effects of homeopathy is gathered and measured.

Randomised placebo-controlled trials

Randomised Controllled Trials (RCTs) are widely recognised as one of the most reliable type of clinical trial. During an RCT, volunteer ‘patients’ are placed, at random,  into 2 or more groups. One group takes a standard treatment – this is called the Control Group. A second group  will receive the treatment being tested. When there is no standard treatment available for the Control Group, a dummy or placebo treatment is used. Sometimes neither the researchers or the patients involved in the trial know who is taking which treatment. This is known as a ‘double blind’ trial.

  • By 2014 there were a total of 104 good-quality placebo-controlled RCTs recording the effects of homeopathy and published in peer-reviewed journals.
  • 41% of the RCTs reported a balance of positive evidence, 5% a balance of negative evidence, and 54% have not been conclusively positive or negative.

Systematic Reviews

The most solid evidence for a treatment comes when the results of a number of RCTs are analysed together. This is known as a systematic review. Six out of seven major systematic reviews of RCTs in homeopathy have concluded (with important caveats) that homeopathy has an effect greater than placebo.  Systematic reviews of RCTs in specific medical areas have presented positive conclusions for homeopathy in six: childhood diarrhoea, hay fever, post-operative ileus, respiratory tract infection, rheumatic diseases and vertigo. 

Find more about the kinds of conditions that respond well to homeopathy here. 

Non-randomised studies – the patient’s experience 

Although less established than the RCT method, using clinical data taken from real patients is  an increasingly important part of evidence-based medicine. Information from everyday clinical practice is particularly valuable in the study of homeopathy. Many patients referred for homeopathic treatment have complex or multiple health problems and would not be accepted for a RCT trial. This also applies to children, older people and those who are pregnant – all of whom can respond well to homeopathy. Studies of this kind are neither randomised nor controlled but they can help show where RCT research might be targeted. There are 21 non-randomised studies that have focused on a particular medical condition or set of conditions. References to these studies are listed here


The Homeopathy Research Institute

The Homeopathy Research Institute (HRI) conducts and promotes high-quality scientific research into homeopathy and its website has a free database of the latest trails and studies. The HRI was founded by physicist, Dr Alexander Tournier, who previously worked as an independent researcher for Cancer Research UK. In this video he explains his fascination with homeopathy.