Written by Karen Pilkington, Edzard Ernst and the CAM-Cancer Consortium.
Updated July 12, 2016


What is it?

Description and name

Homeopathy (or homoeopathy) is a system of medicine based on the similia (‘treating like with like’) principle. It usually entails taking highly diluted remedies by mouth.


Homeopathic remedies are frequently made from natural substances, e.g. plants or minerals, but in principle they can originate from any material (e.g. Berlin Wall remedy) or even non-material sources (e.g. X-ray remedy).

Application and dosage

Homeopathy is defined as “a therapeutic method using preparations of substances whose effects when administered to healthy subjects correspond to the manifestation of the disorder in the individual patient”.1 In other words it is based on the similia principle which states that “substances may be used to treat disorders whose manifestations are similar to those which they will themselves induce in a healthy subject (Similia similibus curentur = ‘let like be cured by like’).1

Homeopathic preparations are produced through a process of serial dilution and succussion/shaking (potentisation) of the “mother tincture”. Preparations are available in a range of dilutions, from low dilutions where concentrations of the original substance are measurable, to extremely high dilutions in which it is unlikely that a single molecule of the original substance remains. Homeopathic potencies are designated by a number and a letter. The number refers to the number of successive serial dilutions to which the starting material has been subjected. The letter refers to the scale used, the decimal (D or X) and centesimal scales (C) being those most widely used. In the decimal method a 1 in 10 dilution is used at each stage while in the centesimal method a 1 in 100 dilution is used in successive stages.1

Homeopathic remedies are usually prescribed on a highly individualized basis; ideally, the totality of the patient’s complaints should match the “drug picture” of the remedy which has been defined in so-called “provings”, i.e. homeopathic pathogenetic trials. These are studies which test a substance at a non-toxic level on healthy volunteers to determine the symptoms it provokes and which, according to the similarity principle, it may be used to treat.2

Today, there are several variations of homeopathy as described above e.g. isopathy (homeopathically diluted remedies derived from the causative agent of the disease itself), or homotoxicology (illness is understood as the body’s inability to effectively cope with its burden of toxins), or complex homeopathy (combination of two or more homeopathic medicines in a standardised mixture), or clinical homeopathy (one or more single remedies for standard clinical situations).1


Homeopathy was developed by the German doctor Samuel Hahnemann (1755-1843) and became popular, first in Europe, then also in a wide variety of countries around the world, especially in the US, India and South America. When more and more effective pharmacological treatments were discovered, the popularity decreased. Recently, it has experienced somewhat of a renaissance in parallel with the growing interest in CAM.

Today homeopathy is practised both by doctors, other health professionals and by lay homeopaths (or “professional homeopaths”). The former two groups are statutorily regulated by their professional bodies, while the latter are often not regulated. In the UK, for example, anyone regardless of background can currently practise as a homeopath. Homeopathic preparations can be prescribed by a homeopath during a consultation but can also be purchased from health food shops, some pharmacies or online suppliers.

Claims of efficacy

Homeopaths believe that homeopathic remedies stimulate the body’s own healing powers (vis medicatrix naturae), i.e. the inherent ability of an organism to overcome disease and disorder and regain its health.1 Therefore, Hahnemann viewed homeopathy as a “cure all”.2 Today it is mostly advocated as a treatment or prevention of chronic conditions and often administered as an adjunctive treatment.3

Mechanism of action

No biologically plausible mechanism of action is known. A 2007 systematic review of in-vitro research on high potency effects found that “no positive result was stable enough to be reproduced by all investigators”; however, it also stated that “even experiments with high methodological standard could demonstrate an effect of high potencies”.4 The fact that homeopathic preparations “may exhibit specific physiochemical properties”5 does not mean that a mechanism of action has been identified. Several recent pre-clinical investigations have suggested direct anti-cancer effects of homeopathic preparations on tumour cells, such as apoptosis and stimulation of natural kille cell activity.6,7 However, these findings require independent replications.

Alleged indications

In oncology, homeopathy is mostly but not exclusively used as palliative and supportive care to improve quality of life, to ease or prevent the adverse effects of treatments, or to alleviate or prevent the symptoms of the cancer.

Prevalence of use

This depends crucially on the country and the setting. For instance, homeopathy is popular in France,8 Italy 9 and Germany.10 Some European centres are specialized and use homeopathy for the majority of cancer patients. Elsewhere, it would not usually be used at all or only very rarely. Data from the Netherlands indicate that 19% of all cancer patients used homeopathy.11 A survey of oncology patients in Italy indicated 6.4% used homeopathy.12  Prevalence appears to vary by type of cancer, for example, surveys across a range of European countries suggested higher rates of use in breast cancer (16-24%) compared with gynaecological cancers (<5%).13, 14

Legal issues

Non-doctor homeopaths are in many countries not regulated by statute. In some countries, they are not officially allowed to practise but usually this regulation is not enforced. In some countries, for example the UK, it is illegal for homeopaths to claim they can cure cancer.

Costs and expenditure

Homeopathic remedies tend to be relatively inexpensive. A first consultation with a homeopath can last one hour or longer and can cost between £30 to £120 per session or €120-€180, follow-up sessions are shorter and therefore less costly. In Germany, some health insurers reimburse consultations with homeopathic physicians.15


Karen Pilkington, Edzard Ernst, CAM-Cancer Consortium. Homeopathy [online document]. http://cam-cancer.org/The-Summaries/Other-CAM/Homeopathy. July 12, 2016.

Document history

Last updated and revised in July 2016 by Karen Pilkington.
Updated in May 2013 by Edzard Ernst.
Updated and revised in November 2011 by Edzard Ernst.
First published in June 2010, authored by Edzard Ernst.


  1. Swayne J. International dictionary of homeopathy. Churchill Livingstone, Edinburgh. 2000.
  2. Ernst E. The heresy of homoeopathy. Br Homeopath J 1998; 87: 28-32.
  3. Spence DS, Thompson EA, Barron SJ. Homeopathic treatment for chronic disease: a 6-year, university-hospital outpatient observational study. J Altern Complement Med 2005; 11: 793-798.
  4. Witt CM, Bluth M, Albreacht H et al. The in vitro evidence for an effect of high homeopathic potencies. A systematic review of the literature. Complement Ther Med 2007; 15(2): 128-138.
  5. Baumgartner S, Wolf M, Skrabal P et al. High-field 1HT1 and T2 NMR relaxation time measurements of H2O in homeopathic preparations of quartz, sulfur, and copper sulfate. Naturwissenschaften 2009; 96: 1079-1089.
  6. Preethi K, Ellanghiyil S, Kuttan G et al. Induction of apoptosis of tumor cells by some potentiated homeopathic drugs: implications on mechanism of action. Integr Cancer Ther 2012; 11: 172-82.
  7. Toliopoulos IK, Simos Y, Bougiouklis D et al. Stimulation of natural killer cells by homoeopathic complexes: An in vitro and in vivo pilot study in advanced cancer patients. Cell Biochem Funct 2013; doi: 10.1002/cbf.2960.
  8. Thomas-Schoemann A, Alexandre J, Mongaret C et al. Use of antioxidant and other complementary medicine by patients treated by antitumor chemotherapy: a prospective study. [in French]. Bull Cancer 2011; 98(6): 645-653.
  9. Clerici CA, Veneroni L, Giacon B et al. Complementary and alternative medical therapies used by children with cancer treated at an Italian pediatric oncology unit. Pediatr Blood Cancer 2009; 53(4): 599-604.
  10. Längler A, Spix C, Edelhauser F et al. Use of homeopathy in pediatric oncology in Germany. Evid Based Complement Alternat Med 2011; 2011: 867151.
  11. Singendonk M, Kaspers GJ, Naafs-Wilstra M et al. High prevalence of complementary and alternative medicine use in the Dutch pediatric oncology population: a multicenter survey. Eur J Pediatr 2013; 172: 31-7.
  12. Bonacchi, A., L. Fazzi, A. Toccafondi, M. Cantore, A. Mambrini, M. G. Muraca, G. Banchelli, M. Panella, F. Focardi, R. Calosi, F. Di Costanzo, M. Rosselli and G. Miccinesi. Use and perceived benefits of complementary therapies by cancer patients receiving conventional treatment in Italy. J Pain Symptom Manage 2014 47(1): 26-34.
  13. Molassiotis A, Scott JA, Kearney N et al. Complementary and alternative medicine use in breast cancer patients in Europe. Support Care Cancer 2006;14:260-7.
  14. Molassiotis A, Browall M, Milovics L et al. Complementary and alternative medicine use in patients with gynecological cancers in Europe. Int J Gynecol Cancer 2006;16 Suppl 1:219-24.
  15. Deutscher Zentralverein Homöopathischer Ärzte. Homöopathie und Kostenerstattung. [online document]. Available at http://www.homoeopathie-online.info/kostenerstattung-einer-aerztlichen-homoeopathischen-behandlung/, accessed 12 July 2016.
  16. Ernst E. A systematic review of systematic reviews of homeopathy. Br J Clin Pharmacol 2002;54:577-582.
  17. Kassab S, Cummings M, Berkovitz S et al. Homeopathic medicines for adverse effects of cancer treatments. Cochrane Database of Syst Rev 2009;2:CD004845.
  18. Pommier P, Gomez F, Sunyach MP et al. Phase III randomized trial of Calendula officinalis compared with trolamine for the prevention of acute dermatitis during irradiation for breast cancer. J Clin Oncol 2004;22:1447-53.
  19. Oberbaum M, Yaniv I, Ben-Gal Y et al. A randomized, controlled clinical trial of the homeopathic medication TRAUMEEL S® in the treatment of chemotherapy-induced stomatitis in children undergoing stem cell transplantation. Cancer 2001;92:684-90
  20. Sencer SF, Zhou T, Freedman LS et al. Traumeel S in preventing and treating mucositis in young patients undergoing SCT: a report of the Children's Oncology Group. Bone Marrow Transplant 2012;47:1409-11.
  21. Steinmann D, Eilers V, Beynenson D et al. Effect of Traumeel S on pain and discomfort in radiation-induced oral mucositis: a preliminary observational study. Altern Ther Health Med 2012;18:12-8.
  22. Pérol D, Provençal J, Hardy-Bessard AC et al. Can treatment with Cocculine improve the control of chemotherapy-induced emesis in early breast cancer patients? A randomized, multi-centered, double-blind, placebo-controlled Phase III trial. BMC Cancer 2012;12:603.
  23. Frass M, Friehs H, Thallinger C et al. Influence of adjunctive classical homeopathy on global health status and subjective wellbeing in cancer patients - A pragmatic randomized controlled trial. Complement Ther Med 2015;23:309-17.
  24. Rostock M, Naumann J, Guethlin C et al. Classical homeopathy in the treatment of cancer patients--a prospective observational study of two independent cohorts. BMC Cancer 2011;11:19.