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.
Evidence base
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
Trial evidence
Encouraging results:
Fibromyalgia
Low back pain
Chronic fatigue syndrome
Pain of unwanted lactation
Mild traumatic brain injury
Childhood diarrhoea
Glue ear
Negative results:
Rheumatoid arthritis
Ankylosing spondylitis
Otitis media
Generalised anxiety
Asthma
References
Linde K, et al. Are the clinical effects of homoeopathy placebo effects? A meta-analysis. Lancet 1997; 350: 834–43.
Ernst E. A systematic review of systematic reviews of homoeopathy Br J Clin Pharmacol 2002; 54: 577–82.
Vickers A J, Smith C. Homoeopathic Oscillococcinum for preventing and treating influenza and influenza-like syndromes. Cochrane Library. Issue 4. Chichester: Wiley; 2004.
Jonas W B, et al. Homoeopathy and rheumatic disease. Rheum Dis Clin North Am 2000; 26: 117–23.
Jacobs J, et al. Homoeopathy for childhood diarrhoea. Pediatr Infect Dis J 2003; 22: 229–34.
Jonas W B, et al. A systematic review of the quality of homoeopathic clinical trials BMC Complement Altern Med 2001; 1: 12.
Shang A, et al. Are the clinical effects of homoeopathy placebo effects? Comparative study Lancet 2005; 366: 726–32.
Schmidt K, Ernst E. MMR vaccination advice over the internet Vaccine 2003; 21: 1044–7.
Thompson E, et al. A preliminary audit investigating remedy reactions including adverse events in routine homoeopathic practice. Homeopathy 2004; 93: 203–9.
