homeopathic dilution. In this process, the selected substance is repeatedly diluted until the final product is chemically indistinguishable from the diluent. Often not even a single molecule of the original substance can be expected to remain in the product.[4] Between each dilution homeopaths may hit and/or shake the product, claiming this makes the diluent "remember" the original substance after its removal. Practitioners claim that such preparations, upon oral intake, can treat or cure disease.[5]
All relevant scientific knowledge about physics, chemistry, biochemistry and biology contradicts homeopathy.[6] Homeopathic remedies are typically biochemically inert, and have no effect on any known disease.[7][8][9] Its theory of disease, centered around principles Hahnemann termed miasms, is inconsistent with subsequent identification of viruses and bacteria as causes of disease. Clinical trials have been conducted and generally demonstrated no objective effect from homeopathic preparations.[10][11][12]: 206 [13] The fundamental implausibility of homeopathy as well as a lack of demonstrable effectiveness has led to it being characterized within the scientific and medical communities as quackery and fraud.[14][15][16]
Homeopathy achieved its greatest popularity in the 19th century. It was introduced to the United States in 1825, and the first American homeopathic school opened in 1835. Throughout the 19th century, dozens of homeopathic institutions appeared in Europe and the United States. During this period, homeopathy was able to appear relatively successful, as other forms of treatment could be harmful and ineffective. By the end of the century the practice began to wane, with the last exclusively homeopathic medical school in the United States closing in 1920. During the 1970s, homeopathy made a significant comeback, with sales of some homeopathic products increasing tenfold. The trend corresponded with the rise of the
New Age movement, and may be in part due to chemophobia
, an irrational aversion to synthetic chemicals, and the longer consultation times homeopathic practitioners provided.
In the 21st century, a series of meta-analyses have shown that the therapeutic claims of homeopathy lack scientific justification. As a result, national and international bodies have recommended the withdrawal of government funding for homeopathy in healthcare. National bodies from Australia, the United Kingdom, Switzerland and France, as well as the European Academies' Science Advisory Council and the Russian Academy of Sciences have all concluded that homeopathy is ineffective, and recommended against the practice receiving any further funding.[17][18][19][20] The National Health Service in England no longer provides funding for homeopathic remedies and asked the Department of Health to add homeopathic remedies to the list of forbidden prescription items.[21][22][23] France removed funding in 2021,[24][25] while Spain has also announced moves to ban homeopathy and other pseudotherapies from health centers.[26]
History
Homeopathy was created in 1796 by Samuel Hahnemann.[27] Hahnemann rejected the mainstream medicine of the late 18th century as irrational and inadvisable, because it was largely ineffective and often harmful.[28][29] He advocated the use of single drugs at lower doses and promoted an immaterial, vitalistic view of how living organisms function.[30] The term homeopathy was coined by Hahnemann and first appeared in print in 1807.[31] He also coined the expression "allopathic medicine", which was used to pejoratively refer to traditional Western medicine.[32]
Concept
Hahnemann conceived of homeopathy while translating a medical treatise by the Scottish physician and chemist William Cullen into German. Being sceptical of Cullen's theory that cinchona cured malaria because it was bitter, Hahnemann ingested some bark specifically to investigate what would happen. He experienced fever, shivering and joint pain: symptoms similar to those of malaria itself. From this, Hahnemann came to believe that all effective drugs produce symptoms in healthy individuals similar to those of the diseases that they treat.[33] This led to the name "homeopathy", which comes from the Greek: ὅμοιοςhómoios, "-like" and πάθοςpáthos, "suffering".[34]
The doctrine that those drugs are effective which produce symptoms similar to the symptoms caused by the diseases they treat, called "the law of similars", was expressed by Hahnemann with the Latin phrase
similia similibus curentur, or "like cures like".[3] Hahnemann's law of similars is unproven and does not derive from the scientific method.[35] An account of the effects of eating cinchona bark noted by Oliver Wendell Holmes, published in 1861, failed to reproduce the symptoms Hahnemann reported.[36]: 128 Subsequent scientific work showed that cinchona cures malaria because it contains quinine, which kills the Plasmodium falciparum parasite that causes the disease; the mechanism of action is unrelated to Hahnemann's ideas.[37]
Provings
Hahnemann began to test what effects various substances may produce in humans, a procedure later called "homeopathic proving". These tests required subjects to test the effects of ingesting substances by recording all their symptoms as well as the ancillary conditions under which they appeared.[38] He published a collection of provings in 1805, and a second collection of 65 preparations appeared in his book, Materia Medica Pura (1810).[39]
As Hahnemann believed that large doses of drugs that caused similar symptoms would only aggravate illness, he advocated for extreme dilutions. A technique was devised for making dilutions that Hahnemann claimed would preserve the substance's therapeutic properties while removing its harmful effects.[40] Hahnemann believed that this process enhanced "the spirit-like medicinal powers of the crude substances".[41] He gathered and published an overview of his new medical system in his book, The Organon of the Healing Art (1810), with a sixth edition published in 1921 that homeopaths still use today.[42]
Miasms and disease
In the Organon, Hahnemann introduced the concept of "miasms" as the "infectious principles" underlying chronic disease[43] and as "peculiar morbid derangement[s] of vital force".[44] Hahnemann associated each miasm with specific diseases, and thought that initial exposure to miasms causes local symptoms, such as skin or venereal diseases. His assertion was that if these symptoms were suppressed by medication, the cause went deeper and began to manifest itself as diseases of the internal organs.[45] Homeopathy maintains that treating diseases by directly alleviating their symptoms, as is sometimes done in conventional medicine, is ineffective because all "disease can generally be traced to some latent, deep-seated, underlying chronic, or inherited tendency".[46] The underlying imputed miasm still remains, and deep-seated ailments can be corrected only by removing the deeper disturbance of the vital force.[47]
Hahnemann's
cataracts.[49] Since Hahnemann's time, other miasms have been proposed, some replacing illnesses previously attributed to the psora, including tuberculosis and cancer miasms.[45]
Hahnemann's miasm theory remains disputed and controversial within homeopathy even in modern times. The theory of miasms has been criticized as an explanation developed to preserve the system of homeopathy in the face of treatment failures, and for being inadequate to cover the many hundreds of sorts of diseases, as well as for failing to explain disease predispositions, as well as genetics, environmental factors, and the unique disease history of each patient.[12]: 148–9
19th century: rise to popularity and early criticism
Homeopathy achieved its greatest popularity in the 19th century. It was introduced to the United States in 1825 by Hans Birch Gram, a student of Hahnemann.[50] The first homeopathic school in the United States opened in 1835 and the American Institute of Homeopathy was established in 1844. Throughout the 19th century, dozens of homeopathic institutions appeared in Europe and the United States,[51] and by 1900, there were 22 homeopathic colleges and 15,000 practitioners in the United States.[52]
Because medical practice of the time relied on treatments which were often ineffective and harmful, patients of homeopaths often had better outcomes than those being treated by medical practitioners.
science-based medicine.[54] One reason for the growing popularity of homeopathy was its apparent success in treating people suffering from infectious disease epidemics.[55] During 19th-century epidemics of diseases such as cholera, death rates in homeopathic hospitals were often lower than in conventional hospitals, where the treatments used at the time were often harmful and did little or nothing to combat the diseases.[56]
Even during its rise in popularity, homeopathy was criticized by scientists and physicians.
Homœopathy and Its Kindred Delusions (1842).[36] The members of the French Homeopathic Society observed in 1867 that some leading homeopaths of Europe not only were abandoning the practice of administering infinitesimal doses but were also no longer defending it.[59] The last school in the United States exclusively teaching homeopathy closed in 1920.[42]
Revival in the 20th century
According to academics
Nazi regime in Germany was fond of homeopathy, and spent large sums of money on researching its mechanisms, but without gaining a positive result.[60] Unschuld also states that homeopathy never subsequently took root in the United States, but remained more deeply established in European thinking.[61] In the United States, the Food, Drug, and Cosmetic Act of 1938 (sponsored by Royal Copeland, a Senator from New York and homeopathic physician) recognized homeopathic preparations as drugs. In the 1950s, there were only 75 solely homeopathic practitioners in the U.S.[62] By the mid to late 1970s, homeopathy made a significant comeback and the sales of some homeopathic companies increased tenfold.[63]
Some homeopaths credit the revival to Greek homeopath
New Age movement.[29]Bruce Hood has argued that the increased popularity of homeopathy in recent times may be due to the comparatively long consultations practitioners are willing to give their patients, and to a preference for "natural" products, which people think are the basis of homeopathic preparations.[66]
Towards the end of the century opposition to homeopathy began to increase again; with William T. Jarvis, the President of the National Council Against Health Fraud, saying that "Homeopathy is a fraud perpetrated on the public with the government's blessing, thanks to the abuse of political power of Sen. Royal S. Copeland."[67]
21st century: renewed criticism
Since the beginning of the 21st century, a series of
Science and Technology Committee of the United Kingdom House of Commons recommended that homeopathy should no longer receive National Health Service (NHS) funding due its lack of scientific credibility;[68] NHS funding for homeopathy ceased in 2017.[22] They also asked the Department of Health in the UK to add homeopathic remedies to the list of forbidden prescription items.[23]
In 2015, the National Health and Medical Research Council of Australia found that "there are no health conditions for which there is reliable evidence that homeopathy is effective".[69] The federal government only ended up accepting three of the 45 recommendations made by the 2018 review of Pharmacy Remuneration and Regulation.[70] The same year the US Food and Drug Administration (FDA) held a hearing requesting public comment on the regulation of homeopathic drugs.[71] In 2017 the FDA announced it would strengthen regulation of homeopathic products.[72]
The American non-profit Center for Inquiry (CFI) filed a lawsuit in 2018 against the CVS pharmacy for consumer fraud over its sale of homeopathic medicines.[73] It claimed that CVS was selling homeopathic products on an easier-to-obtain basis than standard medication.[74] In 2019, CFI brought a similar lawsuit against Walmart for "committing wide-scale consumer fraud and endangering the health of its customers through its sale and marketing of homeopathic medicines".[75][76] They also conducted a survey in which they found consumers felt ripped off when informed of the lack of evidence for the efficacy of homeopathic remedies, such as those sold by Walmart and CVS.[77][78]
In 2021, the French healthcare minister phased out social security reimbursements for homeopathic drugs.[24][25] France has long had a stronger belief in the virtues of homeopathic drugs than many other countries and the world's biggest manufacturer of alternative medicine drugs, Boiron, is located in that country.[79] Spain has also announced moves to ban homeopathy and other pseudotherapies.[26] In 2016, the University of Barcelona cancelled its master's degree in Homeopathy citing "lack of scientific basis", after advice from the Spanish Ministry of Health.[80] Shortly afterwards the University of Valencia announced the elimination of its Masters in Homeopathy.[81]
Homeopathic preparations are referred to as "homeopathic remedies".[82] Practitioners rely on two types of reference when prescribing: Materia medica and repertories. A homeopathic materia medica is a collection of "drug pictures", organized alphabetically. A homeopathic repertory is a quick reference version of the materia medica that indexes the symptoms and then the associated remedies for each. In both cases different compilers may dispute particular inclusions in the references.[83] The first symptomatic homeopathic materia medica was arranged by Hahnemann. The first homeopathic repertory was Georg Jahr's Symptomenkodex, published in German in 1835, and translated into English as the Repertory to the more Characteristic Symptoms of Materia Medica in 1838. This version was less focused on disease categories and was the forerunner to later works by James Tyler Kent.[84][85] There are over 118 repertories published in English, with Kent's being one of the most used.[86]
Consultation
Homeopaths generally begin with a consultation, which can be a 10–15 minute appointment or last for over an hour, where the patient describes their medical history. The patient describes the "modalities", or if their symptoms change depending on the weather and other external factors.[87] The practitioner also solicits information on mood, likes and dislikes, physical, mental and emotional states, life circumstances, and any physical or emotional illnesses.[88] This information (also called the "symptom picture") is matched to the "drug picture" in the materia medica or repertory and used to determine the appropriate homeopathic remedies. In classical homeopathy, the practitioner attempts to match a single preparation to the totality of symptoms (the simlilum), while "clinical homeopathy" involves combinations of preparations based on the illness's symptoms.[64]
Preparation
thyroid hormone). Homeopaths say this is to ensure accuracy.[90] In the USA the common name must be displayed, although the Latin one can also be present.[89] Homeopathic pills are made from an inert substance (often sugars, typically lactose), upon which a drop of liquid homeopathic preparation is placed and allowed to evaporate.[91][92]
Isopathy is a therapy derived from homeopathy in which the preparations come from diseased or pathological products such as fecal, urinary and respiratory discharges, blood, and tissue.[84] They are called nosodes (from the Greek nosos, disease) with preparations made from "healthy" specimens being termed "sarcodes". Many so-called "homeopathic vaccines" are a form of isopathy.[93] Tautopathy is a form of isopathy where the preparations are composed of drugs or vaccines that a person has consumed in the past, in the belief that this can reverse the supposed lingering damage caused by the initial use.[94] There is no convincing scientific evidence for isopathy as an effective method of treatment.[95]
Some modern homeopaths use preparations they call "imponderables" because they do not originate from a substance but some other phenomenon presumed to have been "captured" by alcohol or lactose. Examples include X-rays[96] and sunlight.[97] Another derivative is electrohomeopathy, where an electric bio-energy of therapeutic value is supposedly extracted from plants. Popular in the late nineteenth century, electrohomeopathy is extremely pseudo-scientific.[98] In 2012, the Allahabad High Court in Uttar Pradesh, India, handed down a decree stating that electrohomeopathy was quackery and no longer recognized it as a system of medicine .[99]
Other minority practices include paper preparations, in which the terms for substances and dilutions are written on pieces of paper and either pinned to the patients' clothing, put in their pockets, or placed under glasses of water that are then given to the patients. Radionics, the use of electromagnetic radiation such as radio waves, can also be used to manufacture preparations. Such practices have been strongly criticized by classical homeopaths as unfounded, speculative, and verging upon magic and superstition.[100][101] Flower preparations are produced by placing flowers in water and exposing them to sunlight. The most famous of these are the Bach flower remedies, which were developed by Edward Bach.[102]
Hahnemann claimed that undiluted doses caused reactions, sometimes dangerous ones, and thus that preparations be given at the lowest possible dose.[103] A solution that is more dilute is described as having a higher "potency", and thus are claimed to be stronger and deeper-acting.[104] The general method of dilution is serial dilution, where solvent is added to part of the previous mixture, but the "Korsakovian" method may also be used. In the Korsakovian method, the vessel in which the preparations are manufactured is emptied, refilled with solvent, with the volume of fluid adhering to the walls of the vessel deemed sufficient for the new batch.[12]: 270 The Korsakovian method is sometimes referred to as K on the label of a homeopathic preparation.[105][106] Another method is Fluxion, which dilutes the substance by continuously passing water through the vial.[107] Insoluble solids, such as granite, diamond, and platinum, are diluted by grinding them with lactose ("trituration").[12]
: 23
Three main logarithmic dilution scales are in regular use in homeopathy. Hahnemann created the "centesimal" or "C scale", diluting a substance by a factor of 100 at each stage. There is also a decimal dilution scale (notated as "X" or "D") in which the preparation is diluted by a factor of 10 at each stage.[108] The centesimal scale was favoured by Hahnemann for most of his life, although in his last ten years Hahnemann developed a quintamillesimal (Q) scale which diluted the drug 1 part in 50,000.[109] A 2C dilution works out to one part of the original substance in 10,000 parts of the solution. In standard chemistry, this produces a substance with a concentration of 0.01% (volume-volume percentage). A 6C dilution ends up with the original substance diluted by a factor of 100−6 (one part in one trillion). The end product is usually so diluted as to be indistinguishable from the diluent (pure water, sugar or alcohol).[40][110] The greatest dilution reasonably likely to contain at least one molecule of the original substance is approximately 12C.[111]
Hahnemann advocated dilutions of 1 part to 1060 or 30C.[112] Hahnemann regularly used dilutions of up to 30C but opined that "there must be a limit to the matter".[38]: 322 To counter the reduced potency at high dilutions he formed the view that vigorous shaking by striking on an elastic surface – a process termed succussion – was necessary.[103] Homeopaths are unable to agree on the number and force of strikes needed, and there is no way that the claimed results of succussion can be tested.[12]: 67–69
Critics of homeopathy commonly emphasize the dilutions involved in homeopathy, using analogies.
drop of some original substance diluted into all the water on earth would produce a preparation with a concentration of about 13C.[113][117][118] A 200C dilution of duck liver, marketed under the name Oscillococcinum, would require 10320 universes worth of molecules to contain just one original molecule in the final substance.[119] The high dilutions characteristically used are often considered to be the most controversial and implausible aspect of homeopathy.[120]
Provings
Homeopaths claim that they can determine the properties of their preparations by following a method which they call "proving".[121] As performed by Hahnemann, provings involved administering various preparations to healthy volunteers. The volunteers were then observed, often for months at a time. They were made to keep extensive journals detailing all of their symptoms at specific times throughout the day. They were forbidden from consuming coffee, tea, spices, or wine for the duration of the experiment; playing chess was also prohibited because Hahnemann considered it to be "too exciting", though they were allowed to drink beer and encouraged to exercise in moderation.[122] At first Hahnemann used undiluted doses for provings, but he later advocated provings with preparations at a 30C dilution,[112] and most modern provings are carried out using ultra-dilute preparations.[123]
Provings are claimed to have been important in the development of the
angina was discovered by looking through homeopathic provings, though homeopaths themselves never used it for that purpose at that time.[125] The first recorded provings were published by Hahnemann in his 1796 Essay on a New Principle.[126] His Fragmenta de Viribus (1805)[127] contained the results of 27 provings, and his 1810 Materia Medica Pura contained 65.[128] For James Tyler Kent's 1905 Lectures on Homoeopathic Materia Medica, 217 preparations underwent provings and newer substances are continually added to contemporary versions.[129][130]
Though the proving process has superficial similarities with clinical trials, it is fundamentally different in that the process is subjective, not
blinded, and modern provings are unlikely to use pharmacologically active levels of the substance under proving.[131] As early as 1842, Oliver Holmes had noted that provings were impossibly vague, and the purported effect was not repeatable among different subjects.[36]
statistical evidence of therapeutic efficacy, which is consistent with the lack of any biologically plausible pharmacological agent or mechanism.[8] Proponents argue that homeopathic medicines must work by some, as yet undefined, biophysical mechanism.[87] No homeopathic preparation has been shown to be different from placebo.[8]
Lack of scientific evidence
The lack of convincing scientific evidence supporting its efficacy
Government Chief Scientific Adviser and head of the Government Office for Science said "homeopathy is nonsense, it is non-science."[143] His predecessor, John Beddington, also said that homeopathy "has no underpinning of scientific basis" and is being "fundamentally ignored" by the Government.[144]
Jack Killen, acting deputy director of the
cherry picked positive results, such as by promoting a particular observational study (one which Goldacre describes as "little more than a customer-satisfaction survey") as if it were more informative than a series of randomized controlled trials.[145]
In an article entitled "Should We Maintain an Open Mind about Homeopathy?"
– writing to other physicians – wrote that "Homeopathy is among the worst examples of faith-based medicine... These axioms [of homeopathy] are not only out of line with scientific facts but also directly opposed to them. If homeopathy is correct, much of physics, chemistry, and pharmacology must be incorrect...".
Plausibility of dilutions
The exceedingly low concentration of homeopathic preparations, which often lack even a single
10:23 campaign groups have highlighted the lack of active ingredients by taking large 'overdoses'.[150] None of the hundreds of demonstrators in the UK, Australia, New Zealand, Canada and the US were injured and "no one was cured of anything, either".[150]
Modern advocates of homeopathy have proposed a concept of "
dose-response relationships characteristic of therapeutic drugs.[153] Homeopaths contend that their methods produce a therapeutically active preparation, selectively including only the intended substance, though in reality any water will have been in contact with millions of different substances throughout its history, and homeopaths cannot account for the selected homeopathic substance being isolated as a special case in their process.[154]
Practitioners also hold that higher dilutions produce stronger medicinal effects. This idea is also inconsistent with observed dose-response relationships, where effects are dependent on the concentration of the active ingredient in the body.[153] Some contend that the phenomenon of hormesis may support the idea of dilution increasing potency,[155][156] but the dose-response relationship outside the zone of hormesis declines with dilution as normal, and nonlinear pharmacological effects do not provide any credible support for homeopathy.[154]
Efficacy
Explanations for efficacy of homeopathic preparations:[12]: 155–167 [157]
The
placebo effect
The intensive consultation process and expectations for the homeopathic preparations may cause the effect
Therapeutic effect of the consultation
The care, concern, and reassurance a patient experiences when opening up to a compassionate caregiver can have a positive effect on the patient's well-being.
Since many diseases or conditions are cyclical, symptoms vary over time and patients tend to seek care when discomfort is greatest; they may feel better anyway but because of the timing of the visit to the homeopath they attribute improvement to the preparation taken.
Non-homeopathic treatment
Patients may also receive standard medical care at the same time as homeopathic treatment, and the former is responsible for improvement.
Cessation of unpleasant treatment
Often homeopaths recommend patients stop getting medical treatment such as surgery or drugs, which can cause unpleasant side-effects; improvements are attributed to homeopathy when the actual cause is the cessation of the treatment causing side-effects in the first place, but the underlying disease remains untreated and still dangerous to the patient.
No individual homeopathic preparation has been unambiguously shown by research to be different from placebo.
Cochrane Collaboration concluded that "the most reliable evidence – that produced by Cochrane reviews – fails to demonstrate that homeopathic medicines have effects beyond placebo."[13]
In 2009, the United Kingdom's
Swiss Federal Office of Public Health later released a statement saying the book was published without the consent of the Swiss government.[165]
Meta-analyses, essential tools to summarize evidence of therapeutic efficacy,[166] and systematic reviews have found that the methodological quality in the majority of randomized trials in homeopathy have shortcomings and that such trials were generally of lower quality than trials of conventional medicine.[167][168] A major issue has been publication bias, where positive results are more likely to be published in journals.[169][unreliable source?][170][171] This has been particularly marked in alternative medicine journals, where few of the published articles (just 5% during the year 2000) tend to report null results.[145] A systematic review of the available systematic reviews confirmed in 2002 that higher-quality trials tended to have less positive results, and found no convincing evidence that any homeopathic preparation exerts clinical effects different from placebo.[8] The same conclusion was also reached in 2005 in a meta-analysis published in The Lancet. A 2017 systematic review and meta-analysis found that the most reliable evidence did not support the effectiveness of non-individualized homeopathy.[172]
Health organizations, including the UK's
FASEB,[175] and the National Health and Medical Research Council of Australia,[161] have issued statements saying that there is no good-quality evidence that homeopathy is effective as a treatment for any health condition.[173] In 2009, World Health Organization official Mario Raviglione criticized the use of homeopathy to treat tuberculosis; similarly, another WHO spokesperson argued there was no evidence homeopathy would be an effective treatment for diarrhoea.[176] They warned against the use of homeopathy for serious conditions such as depression, HIV and malaria.[177] The American College of Medical Toxicology and the American Academy of Clinical Toxicology recommend that no one use homeopathic treatment for disease or as a preventive health measure.[178] These organizations report that no evidence exists that homeopathic treatment is effective, but that there is evidence that using these treatments produces harm and can bring indirect health risks by delaying conventional treatment.[178]
Purported effects in other biological systems
While some articles have suggested that homeopathic solutions of high dilution can have statistically significant effects on organic processes including the growth of
Horizon aired a programme in which British scientists attempted to replicate Ennis' results; they were unable to do so.[188] A 2007 systematic review of high-dilution experiments found that none of the experiments with positive results could be reproduced by all investigators.[189]
In 1988, French immunologist
INSERM.[190] The paper purported to have discovered that basophils released histamine when exposed to a homeopathic dilution of anti-immunoglobulin E antibody. Skeptical of the findings, Nature assembled an independent investigative team to determine the accuracy of the research. After investigation the team found that the experiments were "statistically ill-controlled", "interpretation has been clouded by the exclusion of measurements in conflict with the claim", and concluded, "We believe that experimental data have been uncritically assessed and their imperfections inadequately reported."[191][192][193]
Ethics and safety
External links
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