Homoeopathy was founded by the German physician Samuel Hahnemann (1755–1843). It is built on two key principles.
The law of similars or ‘like cures like’ states that a remedy that causes a certain symptom in a healthy person, such as a headache, can be used to treat the symptom.
According to the second principle, homoeopathic remedies become stronger rather than weaker when submitted to ‘potentisation’, or stepwise dilution, combined with ‘sucussion’ (vigorous shaking). Thus remedies are believed to be clinically effective even if they are so dilute that they are likely not to contain a single molecule of the original substance.
Lack of proofs
Presently there is no scientific rationale for understanding how remedies devoid of pharmacologically active molecules produce clinical effects.
Homoeopaths believe their remedies work via energetic mechanisms but there is no acc-eptable proof for such ‘energy’.
Homoeopaths often see patients with benign chronic conditions such as ENT disorders, headaches, musculoskeletal and digestive problems, respiratory and skin complaints, stress and anxiety.
A thorough history is taken but practitioners usually place less emphasis on physical examination than physicians do.
A meta-analysis of all homoeopathic, placebo-controlled or randomised trials suggested that the risk ratio for clinical improvement with homoeopathy was 2.45 times that with placebo. However, six re-analyses of these data failed to demonstrate efficacy.
Similarly, independent systematic reviews of homoeopathy did not convincingly demonstrate efficacy, except in some rheumatic conditions. Recent randomised controlled trials (RCTs) have provided both encouraging and negative findings.
Many primary studies of homoeopathy have serious methodological limitations. A recent comparison of 110 homoeopathic RCTs with 110 similar studies of conventional treatments concluded that the effects of homoeopathy are placebo effects.
Some homoeopaths advise clients against immunisation of children, which may constitute an indirect risk of seeing a homoeopath. In about one quarter of cases homoeopaths expect to observe an aggravation of symptoms. This is seen as a positive sign indicating the correct remedy has been given.
In low dilutions, homeopathic remedies can have adverse effects such as allergic reactions. Some medicines (for example, corticosteroids and antibiotics) are believed to block the actions of homeopathic drugs.
Professor Ernst is director of complementary medicine at the Peninsula Medical School, University of Exeter and Plymouth
Low back pain
Chronic fatigue syndrome
Pain of unwanted lactation
Mild traumatic brain injury
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