The low concentration of homeopathic remedies, which often lack even a single molecule of the diluted substance,* has been the basis of questions about the effects of the remedies since the 19th century. Modern advocates of homeopathy have suggested that "water memory|water has a memory"that during mixing and succussion, the substance leaves an enduring effect on the water, perhaps a "vibration", and this produces an effect on the patient. This notion has no scientific support.* Pharmacological research has found instead that stronger effects of an active ingredient come from dose-response relationship|higher, not lower doses.
Homeopathic remedies have been the subject of numerous clinical trials. Taken together, these trials showed at best no effect beyond placebo, at worst that homeopathy could be actively harmful.* Although some trials produced positive results,* systematic reviews revealed that this was because of chance, flawed research methods, and reporting bias.* The proposed mechanisms for homeopathy are precluded by the laws of physics from having any effect.* Patients who choose to use homeopathy rather than evidence-based medicine risk missing timely diagnosis and effective treatment of serious conditions such as cancer.* The regulation and prevalence of homeopathy vary greatly from country to country.*
Historical contextHippocrates, in about 400 BC, perhaps originated homeopathy when he prescribed a small dose of Mandrake (plant)|mandrake root – which in larger doses produced mania – to treat mania itself;* in the 16th century the pioneer of pharmacology Paracelsus declared that small doses of "what makes a man ill also cures him."* Samuel Hahnemann (1755–1843) gave homeopathy its name and expanded its principles in the late 18th century. At that time, mainstream medicine used methods like bloodletting and purging, and administered complex mixtures, such as Venice treacle, which was made from 64 substances including opium, myrrh, and viper's flesh.* These treatments often worsened symptoms and sometimes proved fatal.* Hahnemann rejected these practices – which had been extolled for centuries* – as irrational and inadvisable;* instead, he advocated the use of single drugs at lower doses and promoted an immaterial, vitalism|vitalistic view of how living organisms function, believing that diseases have Spirituality|spiritual, as well as physical causes.*
Hahnemann's conceptThe term "homeopathy" was coined by Hahnemann and first appeared in print in 1807.*Hahnemann conceived of homeopathy while translating a medical treatise by the Scottish physician and chemist William Cullen into German. Being skeptical of Cullen's theory concerning cinchona's use for curing malaria, Hahnemann ingested some of the bark specifically to investigate what would happen. He experienced fever, shivering and arthralgia|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, in accord with the "law of similars" that had been proposed by ancient physicians.* An account of the effects of eating cinchona bark noted by Oliver Wendell Holmes, Sr.|Oliver Wendell Holmes, and published in 1861, failed to reproduce the symptoms Hahnemann reported.*
Hahnemann's law of similars is an ipse dixit axiom,* in other words an unproven assertion made by Hahnemann, and not a true natural law|law of nature.*
ProvingHahnemann began to test what effects substances produced in humans, a procedure that would later become known as "homeopathic proving". These tests required subjects to test the effects of ingesting substances by clearly recording all of their symptoms as well as the ancillary conditions under which they appeared.* A collection of provings was published in 1805, and a second collection of 65 remedies appeared in his book, Materia Medica Pura, in 1810.*Since Hahnemann believed that large doses of drugs that caused similar symptoms would only aggravate illness, he advocated extreme dilutions of the substances; he devised a technique for making dilutions that he believed would preserve a substance's therapeutic properties while removing its harmful effects.* Hahnemann believed that this process aroused and enhanced "the spirit-like medicinal powers of the crude substances".* He gathered and published a complete overview of his new medical system in his 1810 book, The Organon of the Healing Art, whose 6th edition, published in 1921, is still used by homeopaths today.*
Miasms and diseaseIn The Organon of the Healing Art, Hahnemann introduced the concept of "miasms" as "infectious principles" underlying chronic disease.* Hahnemann associated each miasm with specific diseases, and thought that initial exposure to miasms causes local symptoms, such as skin or venereal diseases; if however these symptoms were suppressed by medication, the cause went deeper and began to manifest itself as diseases of the internal organs.* Homeopathy maintains that treating diseases by directly opposing 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".* The underlying imputed miasm still remains, and deep-seated ailments can be corrected only by removing the deeper disturbance of the vital force.*Hahnemann originally presented only three miasms, of which the most important was psora (Greek for "itch"), described as being related to any itching diseases of the skin, supposed to be derived from suppressed scabies, and claimed to be the foundation of many further disease conditions. Hahnemann believed psora to be the cause of such diseases as epilepsy, cancer, jaundice, deafness, and cataracts.* Since Hahnemann's time, other miasms have been proposed, some replacing one or more of psora's proposed functions, including tuberculosis and cancer miasms.*The law of susceptibility implies that a negative state of mind can attract hypothetical disease entities called "miasms" to invade the body and produce symptoms of diseases.* Hahnemann rejected the notion of a disease as a separate thing or invading entity, and insisted it was always part of the "living whole".* Hahnemann coined the expression "allopathic medicine", which was used to pejoratively refer to traditional Western medicine.*Hahnemann's miasm theory remains disputed and controversial within homeopathy even in modern times. In 1978, Anthony Campbell (physician)|Anthony Campbell, then a consultant physician at the Royal London Homeopathic Hospital, criticised statements by George Vithoulkas claiming that syphilis, when treated with antibiotics, would develop into secondary and tertiary syphilis with involvement of the central nervous system. This conflicts with scientific studies, which indicated penicillin treatment produces a complete cure of syphilis in more than 90% of cases.* Campbell described this as "a thoroughly irresponsible statement that could mislead an unfortunate layman into refusing orthodox treatment".
The theory of miasms has been criticized as an explanation developed by Hahnemann 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.*
19th century: rise to popularity and early criticismHomeopathy achieved its greatest popularity in the 19th century. Dr. John Franklin Gray (1804–1882) was the first practitioner of homeopathy in the United States, beginning in 1828 in New York City. The first homeopathic schools opened in 1830, and throughout the 19th century dozens of homeopathic institutions appeared in Europe and the United States.* By 1900, there were 22 homeopathic colleges and 15,000 practitioners in the United States.* Because medical practice of the time relied on ineffective and often dangerous treatments, patients of homeopaths often had better outcomes than those of the doctors of the time.* Homeopathic remedies, even if ineffective, would almost surely cause no harm, making the users of homeopathic remedies less likely to be killed by the treatment that was supposed to be helping them.* The relative success of homeopathy in the 19th century may have led to the abandonment of the ineffective and harmful treatments of bloodletting and purging and to have begun the move towards more effective, science-based medicine.* One reason for the growing popularity of homeopathy was its apparent success in treating people suffering from infectious disease epidemics.* 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.*From its inception, however, homeopathy was criticized by mainstream science. John Forbes (physician)|Sir John Forbes, physician to Victoria of the United Kingdom|Queen Victoria, said in 1843 that the extremely small doses of homeopathy were regularly derided as useless, "an outrage to human reason".* James Young Simpson said in 1853 of the highly diluted drugs: "No poison, however strong or powerful, the billionth or decillionth of which would in the least degree affect a man or harm a fly."* 19th-century American physician and author Oliver Wendell Holmes, Sr. was also a vocal critic of homeopathy and published an essay in 1842 entitled Homœopathy, and its kindred delusions.* The members of the French Homeopathic Society observed in 1867 that some of the leading homeopathists of Europe not only were abandoning the practice of administering infinitesimal doses but were also no longer defending it.* The last school in the U.S. exclusively teaching homeopathy closed in 1920.*
Revival in the late 20th centuryIn the United States the Food, Drug, and Cosmetic Act of 1938 (sponsored by Royal S. Copeland|Royal Copeland, a United States Senate|Senator from New York and homeopathic physician) recognized homeopathic remedies as drugs. In the 1950s, there were only 75 pure homeopaths practicing in the U.S.* However, by the mid to late 1970s, homeopathy made a significant comeback and sales of some homeopathic companies increased tenfold.* Greek homeopath George Vithoulkas performed a "great deal of research to update the scenarios and refine the theories and practice of homeopathy" beginning in the 1970s, and it was revived worldwide;* in Brazil during the 1970s and in Germany during the 1980s.* The medical profession started to integrate such ideas in the 1990s* and mainstream pharmacy chains recognized the business potential of selling homeopathic remedies.*
Remedies and treatmentHomeopathic practitioners rely on two types of reference when prescribing remedies: materia medica and repertories. A homeopathic materia medica is a collection of "drug pictures", organised alphabetically by "remedy," that describes the symptom patterns associated with individual remedies. A homeopathic repertory is an index of disease symptoms that lists remedies associated with specific symptoms.*Homeopathy uses many animal, plant, mineral, and synthetic substances in its remedies. Examples include arsenicum album (arsenic oxide), natrum muriaticum (sodium chloride or table salt), Lachesis muta (the venom of the Lachesis (genus)|bushmaster snake), opium, and thyroidinum (thyroid hormone). Homeopaths also use treatments called "nosodes" (from the Greek nosos, disease) made from diseased or pathological products suchas fecal, urinary, and respiratory discharges, blood, and tissue.* Homeopathic remedies prepared from healthy specimens are called "sarcodes".
Some modern homeopaths have considered more esoteric bases for remedies, known as "imponderables" because they do not originate from a substance, but from electromagnetic energy presumed to have been "captured" by alcohol or lactose. Examples include X-rays* and sunlight.* Today, about 3,000 different remedies are commonly used in homeopathy. Some homeopaths also use techniques that are regarded by other practitioners as controversial. These include "paper remedies", where the substance and dilution 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, as well as the use of radionics to prepare remedies. Such practices have been strongly criticised by classical homeopaths as unfounded, speculative, and verging upon magic and superstition.*
PreparationIn producing remedies for diseases, homeopaths use a process called "dynamisation" or "potentisation", whereby a substance is diluted with alcohol or distilled water and then vigorously shaken by 10 hard strikes against an elastic body in a process homeopaths call "succussion".* Hahnemann advocated using substances that produce symptoms like those of the disease being treated, but found that undiluted doses intensified the symptoms and exacerbated the condition, sometimes causing dangerous toxic reactions. He therefore specified that the substances be diluted, due to his belief that succussion activated the "vital energy" of the diluted substance* and made it stronger. To facilitate succussion, Hahnemann had a saddle-maker construct a special wooden striking board covered in leather on one side and stuffed with horsehair.* Insoluble solids, such as quartz and oyster shell, are diluted by grinding them with lactose ("trituration").
DilutionsThree logarithmic potency 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. The centesimal scale was favored by Hahnemann for most of his life. A 2C dilution requires a substance to be diluted to one part in 100, and then some of that diluted solution diluted by a further factor of 100. This works out to one part of the original substance in 10,000 parts of the solution.* A 6C dilution repeats this process six times, ending up with the original substance diluted by a factor of 100-6=10-12 (one part in one trillion or 1/1,000,000,000,000). Higher dilutions follow the same pattern. In homeopathy, a solution that is more dilute is described as having a higher potency, and more dilute substances are considered by homeopaths to be stronger and deeper-acting remedies.* The end product is often so diluted as to be indistinguishable from the dilutant (pure water, sugar or alcohol).* There is also a decimal potency scale (notated as "X" or "D") in which the remedy is diluted by a factor of 10 at each stage.*Hahnemann advocated 30C dilutions for most purposes (that is, dilution by a factor of 1060).* In Hahnemann's time, it was reasonable to assume the remedies could be diluted indefinitely, as the concept of the atom or molecule as the Avogadro constant|smallest possible unit of a chemical substance was just beginning to be recognized. The greatest dilution reasonably likely to contain even one molecule of the original substance is 12C.
Critics and advocates of homeopathy alike commonly attempt to illustrate the dilutions involved in homeopathy with analogies.* Hahnemann is reported to have joked that a suitable procedure to deal with an epidemic would be to empty a bottle of poison into Lake Geneva, if it could be succussed 60 times.* Another example given by a critic of homeopathy states that a 12C solution is equivalent to a "pinch of salt in both the North and South Atlantic Oceans",* which is approximately correct.* One-third of a Drop (volume)|drop of some original substance diluted into all the water on earth would produce a remedy with a concentration of about 13C.* A popular homeopathic treatment for the influenza|flu is a 200C dilution of duck liver, marketed under the name oscillococcinum. As there are only about 1080 atoms in the entire observable universe, a dilution of one molecule in the observable universe would be about 40C. Oscillococcinum would thus require 10320 more universes to simply have one molecule in the final substance.* The high dilutions characteristically used are often considered to be the most controversial and implausible aspect of homeopathy.*
Dilution debateNot all homeopaths advocate extremely high dilutions. Remedies at potencies below 4X are considered an important part of homeopathic heritage.*Many of the early homeopaths were originally doctors and generally used lower dilutions such as "3X" or "6X", rarely going beyond "12X". The split between lower and higher dilutions followed ideological lines. Those favoring low dilutions stressed pathology and a strong link to conventional medicine, while those favoring high dilutions emphasised vital force, miasms and a spirituality|spiritual interpretation of disease.* Some products with such relatively lower dilutions continue to be sold, but like their counterparts, they have not been conclusively demonstrated to have any effect beyond that of a placebo effect|placebo.*
ProvingsA homeopathic proving is the method by which the profile of a homeopathic remedy is determined.*At first Hahnemann used undiluted doses for provings, but he later advocated provings with remedies at a 30C dilution,* and most modern provings are carried out using ultradilute remedies in which it is highly unlikely that any of the original molecules remain.* During the proving process, Hahnemann administered remedies to healthy volunteers, and the resulting symptoms were compiled by observers into a "drug picture". The volunteers were observed for months at a time and 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. After the experiments were over, Hahnemann made the volunteers take an oath swearing that what they reported in their journals was the truth, at which time he would interrogate them extensively concerning their symptoms.
Provings have been described as important in the development of the clinical trial, due to their early use of simple control groups, systematic and quantitative procedures, and some of the first application of statistics in medicine.* The lengthy records of self-experimentation by homeopaths have occasionally proven useful in the development of modern drugs: For example, evidence that nitroglycerin might be useful as a treatment for angina pectoris|angina was discovered by looking through homeopathic provings, though homeopaths themselves never used it for that purpose at that time.* The first recorded provings were published by Hahnemann in his 1796 Essay on a New Principle.* His Fragmenta de Viribus (1805)* contained the results of 27 provings, and his 1810 Materia Medica Pura contained 65.* For James Tyler Kent's 1905 Lectures on Homoeopathic Materia Medica, 217 remedies underwent provings and newer substances are continually added to contemporary versions.
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.* As early as 1842, Holmes noted the provings were impossibly vague, and the purported effect was not repeatable among different subjects.*
Physical, mental, and emotional state examination; repertoriesHomeopaths generally begin with detailed examinations of their patients' histories, including questions regarding their physical, mental and emotional states, their life circumstances and any physical or emotional illnesses. "since the least amount of a substance in a solution is one molecule, a 30C solution would have to have at least one molecule of the original substance dissolved in a minimum of 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 [or 1060] molecules of water. This would require a container more than 30,000,000,000 times the size of the Earth."*
Park is also quoted as saying that, "to expect to get even one molecule of the 'medicinal' substance allegedly present in 30X pills, it would be necessary to take some two billion of them, which would total about a thousand tons of lactose plus whatever impurities the lactose contained".*
The laws of chemistry state that there is a limit to the dilution that can be made without losing the original substance altogether.* This limit, which is related to Avogadro constant|Avogadro's number, is roughly equal to homeopathic potencies of 12C or 24X (1 part in 1024).*Scientific tests run by both the BBC's Horizon (BBC TV series)|Horizon and American Broadcasting Company|ABC's 20/20 (US television show)|20/20 programs were unable to differentiate homeopathic dilutions from water, even when using tests suggested by homeopaths themselves.*
EfficacyThe efficacy of homeopathy has been in dispute since its inception. One of the earliest double blind studies concerning homeopathy was sponsored by the British government during World War II in which volunteers tested the efficacy of homeopathic remedies against diluted mustard gas burns.*No individual preparation has been unambiguously shown by research to be different from placebo.* The Methodology|methodological quality of the primary research was generally low, with such problems as weaknesses in study design and reporting, small sample size, and selection bias. Since better quality trials have become available, the evidence for efficacy of homeopathy preparations has diminished; the highest-quality trials indicate that the remedies themselves exert no intrinsic effect.* A review conducted in 2010 of all the pertinent studies of "best evidence" produced by the Cochrane Collaboration concluded that "the most reliable evidence – that produced by Cochrane reviews – fails to demonstrate that homeopathic medicines have effects beyond placebo."*
Publication bias and other methodological issuesThe fact that individual randomized controlled trials have given positive results is not in contradiction with an overall lack of statistical evidence of efficacy. A small proportion of randomized controlled trials inevitably provide false-positive outcomes due to the play of chance: a statistical significance|"statistically significant" positive outcome is commonly adjudicated when the probability of it being due to chance rather than a real effect is no more than 5%—a level at which about 1 in 20 tests can be expected to show a positive result in the absence of any therapeutic effect.* Furthermore, trials of low methodological quality (i.e. ones which have been inappropriately designed, conducted or reported) are prone to give misleading results. In a systematic review of the methodological quality of randomized trials in three branches of alternative medicine, Linde et al. highlighted major weaknesses in the homeopathy sector, including poor randomization.*A related issue is publication bias: researchers are more likely to submit trials that report a positive finding for publication, and journals prefer to publish positive results.* Publication bias has been particularly marked in Alternative medicine|complementary and alternative medicine journals, where few of the published articles (just 5% during the year 2000) tend to report null results.* Regarding the way in which homeopathy is represented in the medical literature, a systematic review found signs of bias in the publications of clinical trials (towards negative representation in mainstream medical journals, and vice-versa in complementary and alternative medicine journals), but not in reviews.*
Systematic reviews and meta-analyses of efficacyBoth meta-analysis|meta-analyses, which statistically combine the results of several randomized controlled trials, and other systematic reviews of the literature are essential tools to summarize evidence of therapeutic efficacy.* Early systematic reviews and meta-analyses of trials evaluating the efficacy of homeopathic remedies in comparison with placebo more often tended to generate positive results, but appeared unconvincing overall.* In particular, reports of three large meta-analyses warned readers that firm conclusions could not be reached, largely due to methodological flaws in the primary studies and the difficulty in controlling for publication bias.* The positive finding of one of the most prominent of the early meta-analyses, published in The Lancet in 1997 by Linde et al.,* was later reframed by the same research team, who wrote:
The evidence of bias [in the primary studies] weakens the findings of our original meta-analysis. Since we completed our literature search in 1995, a considerable number of new homeopathy trials have been published. The fact that a number of the new high-quality trials ... have negative results, and a recent update of our review for the most "original" subtype of homeopathy (classical or individualized homeopathy), seem to confirm the finding that more rigorous trials have less-promising results. It seems, therefore, likely that our meta-analysis at least overestimated the effects of homeopathic treatments.*In 2002, a systematic review of the available systematic reviews confirmed that higher-quality trials tended to have less positive results, and found no convincing evidence that any homeopathic remedy exerts clinical effects different from placebo.*
In 2005, The Lancet medical journal published a meta-analysis of 110 placebo-controlled homeopathy trials and 110 matched medical trials based upon the Swiss Federal Council|Swiss government's Program for Evaluating Complementary Medicine, or PEK. The study concluded that its findings were compatible with the notion that the clinical effects of homeopathy are placebo effects.*
A 2006 meta-analysis of six trials evaluating homeopathic treatments to reduce Oncology|cancer therapy side-effects following radiotherapy and chemotherapy found that there was "insufficient evidence to support clinical efficacy of homeopathic therapy in cancer care".*A 2007 systematic review of homeopathy for children and adolescents found that the evidence for attention-deficit hyperactivity disorder and childhood diarrhea was mixed. No difference from placebo was found for adenoid vegetation, asthma, or upper respiratory tract infection. Evidence was not sufficient to recommend any therapeutic or preventative intervention, and the delay in medical treatment may be harmful to the patient.*
In 2012, a systematic review evaluating evidence of homeopathy's possible adverse effects concluded that "homeopathy has the potential to harm patients and consumers in both direct and indirect ways".* One of the reviewers, Edzard Ernst, supplemented the article on his blog, writing: "I have said it often and I say it again: if used as an alternative to an effective cure, even the most 'harmless' treatment can become life-threatening."*The Cochrane Library found insufficient clinical evidence to evaluate the efficacy of homeopathic treatments for asthma* dementia,* or for the use of homeopathy in induction of labor.* Other researchers found no evidence that homeopathy is beneficial for osteoarthritis,* migraines * or Delayed onset muscle soreness|delayed-onset muscle soreness.*
Health organisations such as the UK's National Health Service,* the American Medical Association,* and the FASEB* have issued statements of their conclusion that there is "no good-quality evidence that homeopathy is effective as a treatment for any health condition."*
Clinical studies of the medical efficacy of homeopathy have been criticised by some homeopaths as being irrelevant because they do not test "classical homeopathy".* There have, however, been a number of clinical trials that have tested individualized homeopathy. A 1998 review* found 32 trials that met their inclusion criteria, 19 of which were placebo-controlled and provided enough data for meta-analysis. These 19 studies showed a pooled odds ratio of 1.17 to 2.23 in favor of individualized homeopathy over the placebo, but no difference was seen when the analysis was restricted to the methodologically best trials. The authors concluded "that the results of the available randomized trials suggest that individualized homeopathy has an effect over placebo. The evidence, however, is not convincing because of methodological shortcomings and inconsistencies." Jay Shelton, author of a book on homeopathy, has stated that the claim assumes without evidence that classical, individualized homeopathy works better than nonclassical variations.*
In a 2012 article published in the Skeptical Inquirer,* Edzard Ernst reviewed the publications of the research group that has published most of the clinical studies of homeopathic treatment from 2005 to 2010. A total of 11 articles, published in both conventional and alternative medical journals, describe three randomized clinical trials (one article), prospective cohort studies without controls (seven articles) and comparative cohort studies with controls (three articles). The diseases include a wide range of conditions from knee surgery, eczema, migraine, insomnia to "any condition of elderly patients". Ernst's evaluation found numerous flaws in the design, conduct and reporting of the clinical studies. Examples include: little detail of the actual homeopathic treatment administered, misleading presentation of controls (comparison of homeopathic plus conventional treatment with conventional treatment, but presented as homeopathic versus conventional treatment); and similar data in multiple articles. He concluded that the misinterpreted weak data made the homeopathy appear to have clinical effects which can be attributed to bias or confounding, and that the "casual reader can be seriously misled".*
Explanations of perceived effectsScience offers a variety of explanations for how homeopathy may appear to cure diseases or alleviate symptoms even though the remedies themselves are inert:*
Effects in other biological systemsWhile some articles have suggested that homeopathic solutions of high dilution can have statistically significant effects on organic processes including the growth of grain,* histamine release by leukocytes,* and enzyme|enzyme reactions, such evidence is disputed since attempts to replicate them have failed.*In 1987, French immunologist Jacques Benveniste submitted a paper to the journal Nature (journal)|Nature while working at INSERM. The paper purported to have discovered that basophils, a type of white blood cell, released histamine when exposed to a homeopathic dilution of anti-immunoglobulin E antibody. The journal editors, sceptical of the results, requested that the study be replicated in a separate laboratory. Upon replication in four separate laboratories the study was published. Still sceptical of the findings, Nature assembled an independent investigative team to determine the accuracy of the research, consisting of Nature editor and physicist Sir John Maddox, American scientific fraud investigator and chemist Walter Stewart, and sceptic James Randi. After investigating the findings and methodology of the experiment, 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."* James Randi stated that he doubted that there had been any conscious fraud, but that the researchers had allowed "wishful thinking" to influence their interpretation of the data.*
Ethics and safetyThe provision of homeopathic remedies has been described as unethical.*
Adverse reactionsSome homeopathic remedies involve poisons such as Belladonna, arsenic, and poison ivy which are highly diluted in the homeopathic remedy, only in rare cases are the original ingredients present at detectable levels. This may be due to improper preparation or intentional low dilution.Serious adverse effects such as seizures and death have been reported or associated with some homeopathic remedies.* Instances of arsenic poisoning have occurred after use of arsenic-containing homeopathic preparations.* Zicam Cold remedy Nasal Gel, which contains 2X (1:100) Zinc gluconate#Safety concerns|zinc gluconate, reportedly caused a small percentage of users to lose their sense of smell;* 340 cases were settled out of court in 2006 for .* In 2009, the FDA advised consumers to stop using three discontinued cold remedy products manufactured by Zicam because it could cause permanent damage to users' sense of smell.* Zicam was launched without a New Drug Application (NDA) under a provision in the FDA's Compliance Policy Guide called "Conditions Under Which Homeopathic Drugs May be Marketed" (CPG 7132.15), but the FDA warned Zicam via a FDA Warning Letter|Warning Letter that this policy does not apply when there is a health risk to consumers.*
Lack of efficacyThe lack of convincing scientific evidence supporting its efficacy* and its use of remedies without active ingredients have led to characterizations as pseudoscience and quackery,* or, in the words of a 1998 medical review, "placebo therapy at best and quackery at worst."* The Chief Medical Officer for England, Sally Davies (doctor)|Dame Sally Davies, has stated that homeopathic remedies are "rubbish" and do not serve as anything more than placebos.* Jack Killen, acting deputy director of the National Center for Complementary and Alternative Medicine, says homeopathy "goes beyond current understanding of chemistry and physics." He adds: "There is, to my knowledge, no condition for which homeopathy has been proven to be an effective treatment."* Ben Goldacre says that homeopaths who misrepresent scientific evidence to a scientific literacy|scientifically illiterate public, have "...walled themselves off from academic medicine, and critique has been all too often met with avoidance rather than argument."* Homeopaths often prefer to ignore meta-analysis|meta-analyses in favour of Cherry picking (fallacy)|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.*
Referring specifically to homeopathy, the House of Commons of the United Kingdom|British House of Commons Science and Technology Committee has stated:
The National Center for Complementary and Alternative Medicine of the United States' National Institutes of Health states:
In lieu of standard medical treatmentOn clinical grounds, patients who choose to use homeopathy in preference to normal medicine risk missing timely diagnosis and effective treatment, thereby worsening the outcomes of serious conditions.* Critics of homeopathy have cited individual cases of patients of homeopathy failing to receive proper treatment for diseases that could have been easily diagnosed and managed with conventional medicine and who have died as a result* and the "marketing practice" of criticizing and downplaying the effectiveness of mainstream medicine.* Homeopaths claim that use of conventional medicines will "push the disease deeper" and cause more serious conditions, a process referred to as "suppression".* Some homeopaths (particularly those who are non-physicians) advise their patients against vaccine|immunisation.* Some homeopaths suggest that vaccines be replaced with homeopathic "nosodes", created from biological materials such as pus, diseased tissue, bacilli from sputum or (in the case of "bowel nosodes") feces.* While Hahnemann was opposed to such preparations, modern homeopaths often use them although there is no evidence to indicate they have any beneficial effects.* Cases of homeopaths advising against the use of anti-malarial drugs have been identified.* This puts visitors to the tropics who take this advice in severe danger, since homeopathic remedies are completely ineffective against the malaria parasite.* Also, in one case in 2004, a homeopath instructed one of her patients to stop taking conventional medication for a heart condition, advising her on 22 June 2004 to "Stop ALL medications including homeopathic", advising her on or around 20 August that she no longer needed to take her heart medication, and adding on 23 August, "She just cannot take ANY drugs – I have suggested some homeopathic remedies ... I feel confident that if she follows theadvice she will regain her health." The patient was admitted to hospital the next day, and died eight days later, the final diagnosis being "acute heart failure due to treatment discontinuation".*In 1978, Anthony Campbell (physician)|Anthony Campbell, then a consultant physician at The Royal London Homeopathic Hospital, criticised statements made by George Vithoulkas to promote his homeopathic treatments. Vithoulkas stated that syphilis, when treated with antibiotics, would develop into secondary and tertiary syphilis with involvement of the central nervous system. Campbell described this as a thoroughly irresponsible statement that could mislead an unfortunate layperson into refusing conventional medical treatment. This claim echoes the idea that treating a disease with external medication used to treat the symptoms would only drive it deeper into the body and conflicts with scientific studies, which indicate that penicillin treatment produces a complete cure of syphilis in more than 90% of cases.*
A 2006 review by W. Steven Pray of the College of Pharmacy at Southwestern Oklahoma State University recommends that pharmacy colleges include a required course in unproven medications and therapies, that ethical dilemmas inherent in recommending products lacking proven safety and efficacy data be discussed, and that students should be taught where unproven systems such as homeopathy depart from evidence-based medicine.*Edzard Ernst, the first Professor of alternative medicine|Complementary Medicine in the United Kingdom and a former homeopathic practitioner,* has expressed his concerns about pharmacists who violate their ethical code by failing to provide customers with "necessary and relevant information" about the true nature of the homeopathic products they advertise and sell:
"My plea is simply for honesty. Let people buy what they want, but tell them the truth about what they are buying. These treatments are biologically implausible and the clinical tests have shown they don't do anything at all in human beings. The argument that this information is not relevant or important for customers is quite simply ridiculous."*Michael Baum, Professor Emeritus of Surgery and visiting Professor of Medical Humanities at University College London (UCL), has described homoeopathy as a "cruel deception".*In an article entitled "Should We Maintain an Open Mind about Homeopathy?"* published in the American Journal of Medicine, Michael Baum and Edzard Ernstwriting to other physicianswrote 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...".
In 2013, Sir Mark Walport, the new UK Government Chief Scientific Adviser and head of the Government Office for Science, had this to say about homeopathy: "My view scientifically is absolutely clear: homoeopathy is nonsense, it is non-science. My advice to ministers is clear: that there is no science in homoeopathy. The most it can have is a placebo effect – it is then a political decision whether they spend money on it or not."* His predecessor, Professor Sir John Beddington, referring to his views on homeopathy being "fundamentally ignored" by the Government, said: "The only one [view being ignored] I could think of was homoeopathy, which is mad. It has no underpinning of scientific basis. In fact all of the science points to the fact that it is not at all sensible. The clear evidence is saying this is wrong, but homoeopathy is still used on the NHS."*
Regulation and prevalenceHomeopathy is fairly common in some countries while being uncommon in others; is highly regulated in some countries and mostly unregulated in others. It is practised worldwide and professional qualifications and licences are needed in most countries.* Regulations vary in Europe depending on the country. In some countries, there are no specific legal regulations concerning the use of homeopathy, while in others, licences or degrees in conventional medicine from accredited universities are required. In Germany, to become a homeopathic physician, one must attend a three-year training program, while France, Austria and Denmark mandate licences to diagnose any illness or dispense of any product whose purpose is to treat any illness.* Some homeopathic treatment is covered by the public health service of several European countries, including France, the United Kingdom, Denmark, and Luxembourg. In other countries, such as Belgium, homeopathy is not covered. In Austria, the public health service requires scientific proof of effectiveness in order to reimburse medical treatments and homeopathy is listed as not reimbursable,* but exceptions can be made;* private health insurance policies sometimes include homeopathic treatment.* The Swiss government, after a 5-year trial, withdrew homeopathy and four other complementary treatments in 2005, stating that they did not meet efficacy and cost-effectiveness criteria,* but following a referendum in 2009 the five therapies are to be reinstated for a further 6-year trial period from 2012.* A December 2012 letter to the Swiss Medical Weekly by Felix Gurtner of the Federal Office of Public Health (FOPH) reiterates these points, noting that the FOPH has concluded that homeopathy is not supported by good evidence and the current temporary reimbursement is on political, not medical, grounds.* The Indian government recognises homeopathy as one of its national systems of medicine,* it has established AYUSH or the Department of Ayurveda, Yoga and Naturopathy, Unani, Siddha and Homoeopathy under the Ministry of Health and Family Welfare (India)|Ministry of Health & Family Welfare.* The Central Council of Homoeopathy was established in 1973 to monitor higher education in Homeopathy, and National Institute of Homoeopathy in 1975.* A minimum of a recognised diploma in homeopathy and registration on a state register or the Central Register of Homoeopathy is required to practice homeopathy in India.*In the United Kingdom, MPs inquired into homeopathy to assess the Government's policy on the issue, including funding of homeopathy under the National Health Service and government policy for licensing homeopathic products. The decision by the House of Commons of the United Kingdom|House of Commons Science and Technology Committee follows a written explanation from the Government in which it told the select committee that the licensing regime was not formulated on the basis of scientific evidence. "The three elements of the licensing regime (for homeopathic products) probably lie outside the scope of the ... select committee inquiry, because government consideration of scientific evidence was not the basis for their establishment," the Committee said. The inquiry sought written evidence and submissions from concerned parties.*In February 2010 the House of Commons Science and Technology Committee concluded that:
The Committee also stated:
In July 2010 the newly appointed UK Secretary of State for Health deferred to local NHS on funding homeopathy. A nineteen-page document details the Government´s response, and it states that "our continued position on the use of homeopathy within the NHS is that the local NHS and clinicians, rather than Whitehall, are best placed to make decisions on what treatment is appropriate for their patients - including complementary or alternative treatments such as homeopathy - and provide accordingly for those treatments." The response also stated that "the overriding reason for NHS provision is that homeopathy is available to provide patient choice".* by February 2011 only one third of PCTs still funded homeopathy.*In 2012 in the United Kingdom, Derby University dropped its homeopathy program, and the University of Westminster ceased enrolling new homeopathy students. Salford University had dropped its homeopathy program the previous year.* In 2013 the Advertising Standards Authority (United Kingdom)|UK Advertising Standards Authority concluded that the Society of Homeopaths were targeting vulnerable ill people and discouraging the use of essential medical treatment while making misleading claims of efficacy for homeopathic products.*