Homeopathy

File:Samuel Hahnemann.png

Samuel Hahnemann, the father of homeopathy

Homeopathy (also spelled homœopathy or homoeopathy) from the Greek words όμοιος, hómoios (similar) and πάθος, páthos (suffering), is a system of alternative medicine that treats "like with like", using remedies that would, in healthy individuals, produce similar symptoms to those it would treat in an ill patient. Practitioners believe that the potency of a remedy can be increased by systematically diluting the dosage, along with succussion or shaking, to a point where the original ingredient is not present.

Although homeopathy is reported to be rapidly growing in popularity, it is controversial and does not satisfy the scientific standards of evidence-based medicine.

The term "homeopathy" was coined by the Saxon physician Samuel Hahnemann (1755–1843) and first published in 1796.

The 'Law of Similars'

Homeopathy is founded on the 'Law of Similars', first expressed by Hahnemann in the exhortation similia similibus curentur or 'let likes cure likes'. The law of similars is based on Hahnemann's observation that a given constellation of symptoms ellicited by a given homepathic remedy in a group of healthy individuals will cure an ill individual exhibiting the same constellations of symptoms. Symptom patterns associated with various remedies are determined by 'provings', in which healthy volunteers are given remedies in homeopathic form, and the physical, mental and spiritual symptoms they develop are recorded and complied by observers. Homeopathic practitioners rely on two types of reference in prescribing. The Homeopathic Materia Medicae are organized by remedy, and describe symptom patterns associated with individual remedies. The Homeopathic repertory are organized by symptom, and list individual remedies associated with various symptoms.

Homeopathic remedies are prepared by dilution of a substence with succussion, or shaking, between dilutions. The remedies themselves are so dilute that they do not contain the original substance. At first, Hahnemann proved substances known as poisons or as remedies. and recorded his findings in his Materia Medica Pura. Kent's Lectures on Homoeopathic Materia Medica (1905) lists 217 remedies, and new chemicals are being added continually to contemporary versions. Homeopathy uses many animal, plant, mineral, and chemical substances of natural or synthetic origin. Examples include Natrum muriaticum (sodium chloride or table salt), lachesis muta (the venom of the bushmaster snake), Opium, and Thyroidinum (thyroid hormone). Other homeopathic remedies, ('isopathic' remedies) involve dilutions of the agent or the product of the disease. Rabies nosode, for example, is made by potentizing the saliva of a rabid dog. Some modern homeopaths are exploring the use of more esoteric substances, known as imponderables because they do not originate from a material substance but from electromagnetic or electrical energy presumed to have been captured by direct exposure (X-ray, Sol (sunlight), Positronium, and Electricitas (electricity)) or through the use of a telescope (Polaris). Recent ventures by homeopaths into esoteric substances include Tempesta (thunderstorm), and Berlin wall.

Today, about 3000 remedies are used in homeopathy; about 300 are based on comprehensive Materia Medica information, about 1500 on relatively fragmentary knowledge, and the rest are used experimentally in difficult clinical situations based on the law of similars, either without knowledge of their homeopathic properties or through knowledge independent of the law of similars. Examples include: the use of an isopathic (disease causing) agent as a first prescription in a 'stuck' case, when the beginning of disease coincides with a specific event such as vaccination; the use of a chemically related substance when a remedy fails yet seems well-indicated; and more recently, the use of substances based on their natural classification (the periodic table or biological taxonomy). This last approach is considered to be promising by some in the homeopathic community, because it allows for grouping remedies and classifying the ever-burgeoning Materia Medica, but is rejected by many purists because it involves speculation about remedy action without proper provings.

There are many methods for determining the most-similar remedy (the simillimum), and homeopaths often disagree about the diagnosis. This is due in part to the complexity of the idea of 'totality of symptoms'; homeopaths do not use 'all' symptoms, but decide which are the most characteristic; this evaluation is the aspect of diagnosis requiring the most knowledge and experience. Finally, the remedy picture in the Materia Medica is always more comprehensive than the symptomatology that one individual ever exhibits. These factors mean that a homeopathic diagnosis remains presumptive until it is verified by testing the effect of the remedy on the patient.

The law of similars is not a 'scientific' law in the sense that it is not built on a hypothesis that can be falsified scientifically; a failure to cure homeopathically can always be attributed to incorrect selection of a remedy.

See also: List of common homeopathic remedies

The 'Theory of Infinitesimals'

The most characteristic—and controversial—principle of homeopathy is that the potency of a remedy can be enhanced (and the side-effects diminished) by dilution, in a procedure known as dynamization or potentization. Liquids are successively diluted (with water, or alcohol for water-insoluble materials) and shaken by ten hard strikes against an elastic body (succussion). Insoluble solids are diluted by grinding them with lactose (trituration). Higher dilutions are considered to be stronger 'deep-acting' remedies.

The dilution factor at each stage is traditionally 1:10 ('D' or 'X' potencies) or 1:100 ('C' potencies). Hahnemann advocated 30C dilutions for most purposes, i.e. dilution by a factor of 100³⁰ = 10⁶⁰. As Avogadro's number is only 6.022 × 10²³ particles/mole, the chance of any molecule of the original substance being present in a 15C solution is small, and it is extremely unlikely that one molecule would be present in a 30C solution. For perspective on these numbers, there are under 10⁵¹ atoms in the Earth, and on the order of 10³² molecules of water in an Olympic size swimming pool; to expect to get one molecule of a 15C solution, one would need to take 1% of the volume of such a pool, or roughly 25 metric tons of water, comparable to the weight of a fully-loaded 18-wheeler. Thus homeopathic remedies that have a high "potency," with overwhelming probability, contain only water, but this water is believed by practitioners of homeopathy to retain some 'essential property' of the substance once present. A key criticism is that any water will, at some time in its history, have been in contact with many different substances. Thus, any drink may be considered to be an extreme dilution of almost any agent you care to mention. Thus, critics argue that almost everyone is almost always receiving homeopathic treatment for almost every condition. Proponents of homeopathy respond that the methodical dilution of a particular substance, beginning with a 10% solution and working downward, is different; exactly why this is different is not clear. Thus modern medicine rejects the possibility of highly diluted preparations having any medicinal action, but attributes claimed effects to the Placebo Effect and/or the Forer effect.

Later homeopaths advocated very high potencies, which could not be made by traditional methods, but required succussion without dilution (Jenichen), higher dilution factors (LM potencies are diluted by a factor of 50,000), or machines which integrate dilution and succussion into a continuous process (Korsakoff). The practitioner's choice of what potency is appropriate is subjective; it involves his or her opinion of how "deep-seated" the disease is; whether it is primarily physical or more mental/emotional; the patient's sensitivity based on the practitioner's intuitive assessment or previous reactions to remedies; and the desired dosing regimen (e.g. low potency repeated often, vs high potency repeated seldom). Generally, French and German homeopaths use lower potencies than their American counterparts. Most homeopaths believe that the choice of potency is secondary to the choice of remedy: i.e. that a well-chosen remedy will act in a variety of potencies, but an approximately matched remedy might act only in certain potencies.

Miasms

By 1816, Hahnemann was concerned at the failure of his homeopathic remedies to produce lasting cures for chronic diseases. He found that "...the non-venereal chronic diseases, after being time and again removed homoeopathically … always returned in a more or less varied form and with new symptoms." To explain this, Hahnemann introduced the miasmatic theory, that three fundamental "miasms" are behind all the chronic diseases of mankind: syphilis, sycosis, and psora. The miasm of psora, he concluded, was behind most of the chronic diseases known to medicine. Miasma, from the Greek for 'stain', was an old medical concept, used for "pestiferous exhalations". The sense of this is indicated by Hahnemann's Note 2 to §11 of the Organon: "...a child with small-pox or measles communicates to a near, untouched healthy child in an invisible manner (dynamically) the small-pox or measles, … in the same way as the magnet communicated to the near needle the magnetic property..."

According to Hahneman, miasmatic infection causes local symptoms, usually in the skin. If these are suppressed by external medication, the disease goes deeper, and manifests itself as organ pathologies. In §80 of the Organon he asserted psora to be the cause of such diseases as epilepsy, cyphosis, cancer, jaundice, deafness, and cataract.

Even in his own time, many followers of Hahneman, including Hering, made almost no reference to Hahnemann’s concept of chronic diseases. Today, some homeopathic practitioners [1] accept that Hahnemann’s theory does not hold up in light of current knowledge in immunology, genetics, microbiology and pathology, and recognise that Hahnemann neglected to identify genetic, congenital, metabolic, nutritional, and degenerative diseases, and failed to differentiate the multitude of different infectious diseases. However, they believe that some elements of his theory are valid. For instance, they believe that the fundamental cause of disease is constitutional (i.e. the susceptibility to becoming ill), and that it is contrary to good health to suppress symptoms, especially skin eruptions and discharges. They also accept Hahneman's concept of latent psora, the early signs of an organism’s imbalance that indicate that treatment is needed to prevent the development of more advanced disease.

History

Theory of disease

In Hahnemann's day, the conventional theory of disease was based on the four humours. Mainstream medicine focused on restoring the balance in the humours, either by attempting to remove an excess of a humour (by such methods as bloodletting and purging, laxatives, enemas and nauseous substances that made patients vomit) or by suppressing symptoms associated with the humours causing trouble, such as by lowering the body temperature of patients who were feverish. By contrast, Hahnemann promoted a view of 'spiritual factors' as the root cause of all disease. Some later homeopaths, in particular James Tyler Kent, put even more emphasis on spiritual factors.[2]

"...for it goes to the very primitive wrong of the human race, the very first sickness of the human race that is the spiritual sickness... which in turn laid the foundation for other diseases."

Vitalism was a part of mainstream science in the 18th century. In the twentieth century, medicine discarded vitalism in favour of the germ theory of disease, following the work of Louis Pasteur, Alexander Fleming, Joseph Lister and many others. Modern medicine sees bacteria and viruses as the causes of many diseases, but Kent, and some modern homeopaths regard them as effects, not causes, of disease. Others have adapted to the views of modern medicine by referring to disturbances in, and stimulation of, the immune system, rather than the vital force.

Hahnemann developed homeopathy after coming upon the idea that 'like cures like' while translating a work on malaria. On reading that Cinchona bark (which contains quinine) was effective because it was bitter, Hahnemann felt this implausible because other substances were as bitter but had no therapeutic value. To understand the effects of Cinchona bark, he decided to take it himself, and saw that his reactions were similar to the symptoms of the disease it was used to treat. At least one writer has suggested that Hahnemann was hypersensitive to quinine, and that he may have had an allergic reaction[3].

For Hahnemann, the whole body and spirit was the focus of therapy, not just the localised disease. Hahnemann spent a lot of time with his patients, asking them not only about their symptoms or illness, but also about their daily lives. This gentle approach contrasted with the violent forms of heroic medicine common at the time, which included techniques such as bleeding as a matter of course.

Homeopathy came to the USA in 1825 and rapidly gained popularity, partly because the excesses of conventional medicine were extreme there, and partly due to the efforts of Constantine Hering. Homeopathy reached a peak of popularity in 1865–1885 and thereafter declined due to a combination of the recognition by the establishment of the dangers of large doses of drugs and bleeding, and dissent between different schools of homeopathy.

Nearly as important as Hahnemann to the development of homeopathy was James Tyler Kent (1849 – 1921). Kent's influence in the USA was limited, but in the UK, his ideas became the homeopathic orthodoxy by the end of the First World War. His most important contribution may be his repertory, which is still used today. Kent's approach was authoritarian, emphasizing the metaphysical and clinical aspects of Hahnemann's teachings, in particular

• insistence on the doctrines of miasm and vitalism;
• emphasis on psychological symptoms (as opposed to physical pathology) in prescribing; and
• regular use of very high potencies.

Kent believed that illness had spiritual causes:

"You cannot divorce medicine and theology. Man exists all the way down from his innermost spiritual, to his outermost natural." (Kent, 1926)

and in the USA, homeopathy came to be associated closely with Swedenborgianism, (the Christian mystical sect of Emanuel Swedenborg, who founded the New Jerusalem Church)[4]. All prominent American homoeopaths in the nineteenth century, from Hering to Kent, were members of the New Jerusalem Church; and the members of the Church were mostly supporters and followers of homoeopathy. In Russia, homoeopathy was similarly closely connected with the Russian Orthodox Church, and the Missionary School of Medicine, founded in England in 1903, was closely associated with the Faculty of Homoeopathy in London in the early 1900's.

Today, the ease with which large databases can be manipulated has profoundly changed the way homeopathy is practised. Today, many homeopaths use computers to sift through thousands of provings and case studies. Because information about lesser-known remedies is more accessible, it is now more common for homeopaths to prescribe them, which has led to an increase in the number of new provings.

See also: List of important homeopaths

Homeopathy around the world

There are estimated to be more than 100,000 physicians practising homeopathy worldwide, with an estimated 500 million people receiving treatment. More than 12,000 medical doctors and licensed health care practitioners administer homeopathic treatment in the UK, France, and Germany. Since 2001, homeopathy is regulated in the European Union by Directive 2001/83/EC; the latest amendments make it compulsory for member states to implement a simple registration procedure for homeopathic remedies.

In the UK, homeopathic remedies may be sold over the counter. The UK has five homeopathic hospitals where treatment, funded by the National Health Service, is available and many regional clinics. Homeopathy is not practised by most of the medical profession, but there is a core of public support, including from the English royal family.

In India, homeopathy has been practised since the middle of the 19th century, and is officially recognized. India has the largest homeopathic infrastructure in the world, with 300,000 qualified homeopaths, 180 colleges, 7500 government clinics, and 307 hospitals.

In the USA, homeopathic remedies are, like all healthcare products, regulated by the Food and Drug Administration. However, the FDA treats homeopathic remedies very differently to conventional medicines. Homeopathic products do not have to be approved by the FDA before sale, they do not have to be proved to be either safe or effective, they do not have to be labeled with an expiration date, and they do not have to undergo finished product testing to verify contents and strength. Unlike conventional drugs, homeopathic remedies do not have to identify their active ingredients on the grounds that they have few or no active ingredients. In the USA, only homeopathic medicines that claim to treat self-limiting conditions may be sold over the counter; homeopathic medicines that claim to treat a serious disease can be sold only by prescription.

In Germany, about 6,000 physicians specialize in homeopathy. In 1978 homeopathy, anthroposophically extended medicine and herbalism, were recognized as "special forms of therapy", meaning that their medications are freed from the usual requirement of proving efficacy. Since January 1, 2004 homeopathic medications, with some exceptions, are no longer covered by the country's public health insurance. Most private health insurers continue to cover homeopathy.

In Switzerland homeopathic medications were formerly covered by the basic health insurance system, if prescribed by a physician. This ended in June 2005. The Swiss Government, after a 5-year trial, withdrew insurance coverage for homoeopathy and four other complementary treatments because they did not meet efficacy and cost-effectiveness criteria. This applies only to compulsory insurance; homeopathy and other complementary medicine is covered by additional insurance, if the treatment is provided by a medical doctor.

Classical versus non-classical homeopathy

Hahnemann's formulation of homeopathy is often referred to as classical homeopathy. Classical homeopaths use one remedy at a time, and base their prescription also on incidental or constitutional symptoms. However, homeopathic remedies are often used both by professionals and by the public based on formulations marketed for specific medical conditions. Occasionally single remedies are used in this way, but more often, mixtures of several remedies are used in a practice known as complex homeopathy. Some formulations use a 'shotgun' approach of the most commonly indicated single remedies in mixture form, while others, such as those by Heel and Reckeweg, are proprietary mixtures marketed for specific diagnostic critera based on various diagostic systems. Many members of the public are not familiar with classical homeopathy, and equate these practices with homeopathy; others are familiar with the classical approach but regard these as legitimate variants; while others consider it a misuse of the term. Use of non-classical approaches probably exceeds that of classical homeopathy, at least in places where over-the-counter preparations are popular and where many doctors use natural medicines in a conventional clinical setting.

The popularity of homeopathy

In the 1930's the popularity of homeopathy waned, especially in Europe and the USA, partly due to advances in conventional medicine, to the Flexner Report (1910) which led (in the USA) to the closure of virtually all medical schools teaching alternative medicine. Homeopathy had a renaissance in the 1970's, largely because of George Vithoulkas in Europe and the USA, that continues to this day. In the USA, in 1995, retail sales of homeopathic medicines were estimated at US$201 million, and growing at 20% per year, according to the American Homeopathic Pharmaceutical Association, and the number of homeopathic practitioners increased from fewer than 200 in the 1970's to approximately 3,000 in 1996. The increased popularity of homeopathy since the 1970's accompanied a rise in interest in alternative medicine.

Science and homeopathy

Some patients report benefits after conventional treatment has failed [5], although scientists would explain this as placebo or the regression fallacy in analysing results. There is no scientific basis for the actions of homeopathic remedies. The placebo effect can be large, so conventional drugs are tested in large, multi-centre, randomised, placebo-controlled double-blind clinical trials, the object of which is to test whether the drug has an objectively-demonstrable effect that is significantly better than the effect of a placebo. Many clinical trials that partially meet these criteria have investigated homeopathy, and some have indicated some kind of efficacy above placebo[6], while many others have not. However, many of the trials are open to technical criticism or involve samples that are too small to allow firm conclusions to be drawn.

There is scientific agreement that, wherever applicable, an evidence based medicine framework should ideally be used to assess health outcomes and that systematic reviews with strict protocols are essential. Organisations such as the Cochrane Collaboration and Bandolier publish such reviews. The Cochrane Collaboration found insufficient evidence that homeopathy is beneficial for asthma, dementia and induction of labor. They also found no evidence that homeopathic treatment can prevent influenza, but reported that it might shorten the duration of the disease. Bandolier found insufficient evidence that homeopathy is beneficial for osteoarthritis, migraine prophylaxis, flu, delayed-onset muscle soreness,migraine or symptoms of menopause

In August 2005, The Lancet published a meta-analysis of trials of homeopathy, the largest and most rigorous analysis so far, involving 110 placebo-controlled homoeopathy trials and 110 matched conventional-medicine trials . The outcome of this suggested that the clinical effects of homeopathy are likely to be placebo effects. For reactions to this study from homeopaths, see [7] [8]

In 1997, the following statement was adopted as policy of the American Medical Association (AMA) after a report on a number of alternative therapies including homeopathy:[9]

"There is little evidence to confirm the safety or efficacy of most alternative therapies. Much of the information currently known about these therapies makes it clear that many have not been shown to be efficacious. Well-designed, stringently controlled research should be done to evaluate the efficacy of alternative therapies."

Misconceptions about homeopathy

Composition of homeopathic remedies

It is a common misconception that homeopathic remedies use only natural herbal components (akin to herbology). Herbs are used, but homeopathy also uses non-biological substances (such as salts) and components of animal origin, such as duck liver in the remedy oscillococcinum. In herbology, measurable amounts of herbs are used, while in homeopathy the active ingredient is diluted to the point where it is no longer measurable. Homeopathy also uses substances of human origin, called nosodes. Some people have the opposite misconception, that homeopathic remedies are only based on toxic substances like snake venom or mercury.

As the term homeopathy is well known and has good marketing value, the public can be confused by people who have adopted the term for other forms of therapy. For example, some companies combine homeopathic with non-homeopathic substances such as herbs or vitamins, and some preparations marketed as homeopathic contain no homeopathic preparations at all. Classical homeopaths argue that only remedies prepared and prescribed in accordance with the principles of Hahnemann can be called homeopathic. Many producers of homeopathic remedies also produce other types of alternative remedies under the same brand name, which can create confusion for the public.

Homeopathy and vaccination

To some, homeopathy, particularly the use of nosodes, resembles vaccination, in that vaccines contain a small dose of the "disease" against which they are to protect. Hahnemann interpreted the introduction of vaccination by Edward Jenner in 1798 as a confirmation of the law of similars, but the two practices are fundamentally different. A vaccine is usually a bacterium or virus whose ability to produce symptoms has been deliberately weakened, while still providing enough information to the immune system to afford protection. By preparing the immune system of a healthy organism to meet a future attack by the pathogen, vaccination hopes to prevent disease, in contrast to homeopathy's hope, which is to cure it. Another important difference between homeopathic preparations and vaccine, is that vaccine contains measurable amounts of the "disease," whereas homeopathic remedies have been so diluted as to contain no traces at all.

Safety of homeopathic treatment

The FDA considers that there is no real concern over the safety of homeopathic products "because they have little or no pharmacologically active ingredients". There have been a few reports of illness associated with the use of homeopathic products, which may be because some homeopathic remedies are prepared by serial dilution of toxic substances, presenting a risk that by accident they might contain undiluted toxic substances. The medical literature contains several case reports of poisoning by heavy metals such as arsenic and mercury found in homeopathic remedies. However, in cases that they reviewed, the FDA discounted the homeopathic product involved as the cause of the adverse reactions. In one case, arsenic was implicated, although FDA analysis revealed that the concentration of arsenic was too low to cause concern. Perhaps the main concern about the safety of homeopathy arises not from the products themselves, but from the possible withholding of more efficacious treatment, or from misdiagnosis of dangerous conditions by a non-medically qualified homeopath.[10]

Sources

• Magical Thinking in Complementary and Alternative Medicine from the Skeptical Enquirer
• Homeopathy: The Test - programme summary from BBC
• Linde K, Melchart D (1998). "Randomized controlled trials of individualized homeopathy: a state-of-the-art review". J Altern Complement Med. 4 (4): 371–88. PMID 9884175.
• Cucherat M, Haugh MC, Gooch M, Boissel JP (2000). "Evidence of clinical efficacy of homeopathy. A meta-analysis of clinical trials. HMRAG. Homeopathic Medicines Research Advisory Group". Eur J Clin Pharmacol. 56 (1): 27–33. PMID 10853874.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Walach H "Unspezifische Therapie-Effekte. Das Beispiel Homöopathie" [PhD Thesis]. Freiburg, Germany: Psychologische Institut, Albert-Ludwigs-Universität Freiburg, (1997)
• Ernst E. "Classical homeopathy versus conventional treaments: a systematic review" Perfusion, (1999); 12: 13-15
• Almeida RM (2003). "A critical review of the possible benefits associated with homeopathic medicine". Rev Hosp Clin Fac Med Sao Paulo. 58 (6): 324–31. PMID 14762492.
• Linde K, Clausius N, Ramirez G, Melchart D, Eitel F, Hedges LV, Jonas WB (1997). "Are the clinical effects of homeopathy placebo effects? A meta-analysis of placebo-controlled trials". Lancet. 350 (9081): 834–43. PMID 9310601.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Kleijnen J, Knipschild P, ter Riet G (1991). "Trials of homeopathy". BMJ. 302 (6782): 960. PMID 1827743.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Bandolier Homeopathy - dilute information and little knowledge [11]
• Linde K, Scholz M, Ramirez G, Clausius N, Melchart D, Jonas WB (1999). "Impact of study quality on outcome in placebo-controlled trials of homeopathy". J Clin Epidemiol. 52 (7): 631–6. PMID 10391656.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• James Randi Educational Foundation. "The JREF Million Dollar Paranormal Challenge 'FAQ'". [12] Retrieved 13 September, 2005.
• footnote to pp.12-13, Hahnemann's Chronic Diseases, ed. P. Dudley, B. Jain Publishers, 1998 reprint

External links

• Online etext of Hahnemann's Organon der Heilkunst: German original and English translation

Neutral

• A recent article on homeopathy testing from the Annals of Internal Medicine
• BBC's Horizon on homeopathy (transcripts, discussion, etc.)
• Homeopathy In Perspective — critical online book, covering the history and present state of homeopathy
• FDA's view of homeopathy
• Water Structure and Behaviour— balanced and up-to-date references to current scientific understanding of water, with specific entries on "memory effects" and homeopathy

Supportive

• Extensive Homeopathy Information and Discussion Forum
• North American Society of Homeopaths
• The Society of Homeopaths - UK Organisation Representing Professional Homeopaths
• Homeopathy Links from The Holistic Medicine Resource Center
• Introduction and Information on Homeopathy
• Homeo Cure Center - Forum discussing health issues, homeopathic remedies, and veterinary homeopathy.
• Complementary Medicine - Therapies: Homeopathy BBC's "Complementary Medicine" article on Homeopathy
• Referrals to Certified Classical Homeopaths
• Alliance of Registered Homeopaths
• Homéopathe International — The English language version of Homéopathe International
• Homeopathy Timeline with a wealth of historical and biographical information
• Adjuvant homeopathic treatment in Breastcancer, a pilot study [13] (in German)

Critical

• A skeptic's view of homeopathy
• Magical Thinking in Complementary and Alternative Medicine
• Homeopathy: The Ultimate Fake - Stephen Barrett, M.D.
• HomeoWatch (Homeopathy Watch) — A Skeptical Guide to Homeopathic History, Theories, and Current Practices, operated by Stephen Barrett, M.D. (founder of Quackwatch)
• H2G2 entry on homeopathy.
• The Skeptics Dictionary
• "The Scientific Evidence on Homeopathy" - American Council on Science and Health
• A close look at homeopathy
• Dilution or Delusion?
• National Council Against Health Fraud Position Paper on Homeopathy
• Are the clinical effects of homoeopathy placebo effects?.pdf. A 2005 study published in The Lancet.