Homeopathy/Draft

Homeopathy or homoeopathy&mdash;from the Greek hómoios (similar) and páthos (suffering)&mdash;is a system of alternative medicine based on the idea that substances known to cause particular combinations of symptoms in healthy people can also, in low and specially prepared doses, help to cure people whose disease has similar symptoms.

Homeopathy is used by some medical doctors and other licensed health practitioners who use it as an alternative or a complement to conventional treatment for both acute and chronic ailments, by a relatively small number of licensed homeopaths, and by consumers who use it to treat common non-life-threatening acute conditions. Homeopathic medicines (referred to in this article as "remedies" to avoid confusion with conventional medicines) are widely available without the need for a doctor's prescription. Many health insurers cover homeopathic treatment if it is provided by a licensed medical doctor, but many others refuse to do so.

The consensus of medical and scientific judgment is that homeopathy is unfounded. Although many studies have reported that remedies might be effective in particular conditions, these have mostly been small and poorly controlled. The main homeopathic principles make no sense to scientists. The "principle of similars" appears to be an appeal to sympathetic magic, or an over-generalisation of a principle that applies in only a few cases. The "principle of infinitisimals" contradicts both common sense and scientific results; there is no proven mechanism by which remedies might work, given that many of them are so dilute that they contain not a single molecule of the active ingredient. Homeopaths reject these arguments and consider them to be evidence of medical arrogance.

Principles, and historical origins
According to homeopaths, their remedies stimulate the body's "natural healing processes" and invoke the "wisdom of the body". Remedies are derived from substances which, when given in overdose to healthy people, cause symptoms similar to those of the patient being treated; homeopaths claim that these augment the body's own defenses. Hygiene, diet, and other natural therapies are also often used in conjunction with remedies.

Two basic principles are the principle of similars ("like cures like"), and the principle of infinitisimals - the idea that remedies become more potent if they undergo a process called potentization, which consists of repeated dilutions with vigorous shaking (succusion) between each dilution. Individualization of treatment is essential in classical homeopathy, whereby a remedy is chosen based on the person's overall 'syndrome of symptoms', not just a generic disease diagnosis.

History
Hippocrates of Cos (c. 450–380 BCE), who is considered to be the "father of medicine", is also claimed by homeopaths as a pioneer in their own tradition because he taught that "Natural forces within us are the true healers of disease," and that some diseases could be cured by the same things that caused them. The principles of homeopathy were first methodically set out by a German physician, Samuel Hahnemann (1755–1843). In homeopathic theory, every person has a "vital force", with the power to promote healing and/or maintain good health, and the symptoms of a disease reflect efforts of the body to defend itself against infection, environmental assault, or stresses. Homeopathy attempts to strengthen this "vital force" with remedies chosen for their ability (in large doses) to provoke the similar symptoms that the remedy is intended to heal. Many famous people over the past 200 years have been users and advocates of homeopathy, and it is an important thread in the history of medicine.

Hahnemann
In the early 18th century, the conventional medicine was what is now called heroic medicine; its physicians often used large doses of toxic compounds as medicines, and used procedures such as bloodletting and purgingindiscriminately. In 1783, disillusioned with heroic medicine, Hahnemann gave up his medical practice and turned to translating medical books. Among them was the Treatise on Materia Medica by William Cullen. Cullen had written that cinchona bark (which contains quinine) was effective in treating malaria because of its bitter and astringent properties. Hahnemann questioned this, because other substances were as bitter but had no therapeutic value.

Hahnemann saw that the effects of ingesting cinchona were like the symptoms of malaria. He observed similar results with other substances, and so conceived of the law of similars (Latin: similia similibus curentur, "let like be cured by like" )&mdash; the assertion that a disease can be cured by remedies that (in milligram doses) produce the same symptoms as those of the disease. He believed that, by inducing symptoms similar to the disease, the natural healing processes of the body would be stimulated. From these ideas, he developed a new system of health care, which he named "homoeopathy" (meaning "like disease"), and coined the term "allopathy" ("different than disease") for the heroic medicine of the day.

At first, Hahnemann used "crude" doses of substances (doses that still contained some original ingredient). He strove to find the lowest doses that would still be effective, and he concluded that remedies worked better the more he diluted them as long as he “potentized” them, i.e. by serial dilution followed by succussion. Homeopathy thus became inextricably linked with ultradilution. Hahnemann had no explanation as to how or why these potentized remedies might work; he distrusted theoretical explanations and argued that all that mattered was whether a treatment was effective. . Hahnemann coupled his theory with a method of "provings" to determine what symptoms a substance causes and thence what a particular remedy might cure (see below).

Homeopathy in the U.S.A.
The first homeopathic school in the U.S.A. opened in 1835, and in 1844 the first U.S. national medical association, the American Institute of Homeopathy, was established. By the end of the 19th century, 8% of American medical practitioners were homeopaths, with 20 homeopathic colleges and more than 100 homeopathic hospitals. One reason for the popularity of homeopathy was its relative success in combatting the epidemics of the time. Cholera, scarlet fever, typhoid fever, and yellow fever killed many, but death rates in hospitals that used heroic medicine were two- to eight-fold higher than in homeopathic hospitals.

In the early 20th century, the "Flexner Report" triggered major changes in American medical education. Many medical schools, including those teaching homeopathy, were closed, while others turned to a new vision of a biochemical understanding of medicine to replace heroic medicine. The popularity of homeopathy revived after the 1960's, and a 1999 survey reported that over 6 million Americans had used homeopathy in the previous 12 months. The number of homeopathic practitioners in the U.S.A. increased from fewer than 200 in the 1970's to about 3,000 in 1996.

Conflict with conventional medicine
The theory underlying homeopathy is not considered plausible by most scientists, and the treatment advice offered by homeopaths is in disagreement with conventional medicine. The academic view is that homeopathy exploits the placebo effect — i.e. that the only benefits are those induced by suggestion, by arousing hope and alleviating anxiety.

Homeopaths believe that the fundamental causes of disease are internal and constitutional and that infectious disease is not just the result of infection but also of susceptibility. This respect for the body's own defense systems leads them to avoid conventional treatments that suppress symptoms. Physicians consider that most diseases are caused by a combination of external causes (such as viruses, bacteria, toxins, dietary deficiency, physical injury) and physiological dysfunction (including genetic defects and mutations such as those which trigger cancers). Conventional medicine aims to eliminate these causes, although physicians often also use drugs to suppress the discomfort of a disease (e.g., painkillers) or to supplement host resistance based on specific mechanisms, such as immunization.

Homeoprophylaxis
Some homeopaths believe that their remedies can prevent disease, a notion known as "'homeoprophylaxis". A 2006 survey in the U.K. revealed that homeopathic vendors were advising travelers against taking conventional antimalarial drugs, instead recommending a homeopathic remedy. Even the director of the the Royal London Homeopathic Hospital condemned this: "I'm very angry about it because people are going to get malaria—there is absolutely no reason to think that homeopathy works to prevent malaria and you won't find that in any textbook or journal of homeopathy so people will get malaria, people may even die of malaria if they follow this advice"

"Provings"
In homeopathic  drug provings, volunteers are given repeated doses of substances (usually in single-blind or double-blind protocols), and keep a diary of symptoms. These are later recorded in textbooks, called Materia Medica or nowadays in expert system software. These 'provings' provide, for homeopaths, evidence of what a substance causes in overdose and thence what it might cure. The symptom complexes from provings are compared with a patient's symptoms in order to select, for the appropriate remedy, the substance whose effects are closest to the patient's symptoms — the "simillimum". Homeopaths prescribe a remedy (in potentized doses) when a sick person has a syndrome of symptoms that resembles the symptoms that crude doses of the remedy cause in a proving.

In 2006, the U.K. Medicine and Healthcare Products Regulatory Agency altered their regulations to allow evidence from provings to support advertising claims for remedies (justifying phrasing such as “For the relief of...”). Scientists protested, calling this a departure from the principle that claims should be justified by evidence of efficacy.

"Remedies"
In the U.S.A., the federal Food, Drug, and Cosmetic Act (1938) sponsored by Senator Royal Copeland (a former homeopathic medical school dean) gave the Food and Drug Administration (FDA) the power to regulate drugs, and gave legal recognition to the Homœopathic Pharmacopœia of the United States This describes how remedies (defined as "homeopathic drugs") are manufactured. They are subject to less stringent regulation than conventional drugs, which must demonstrate adequate evidence of safety and efficacy; by contrast any substance can become a homeopathic remedy. Remedies are also exempt from good manufacturing practice requirements related to expiration dating, and from finished product testing for identity and strength.

Homeopaths use about 3,000 remedies, made from plants, trees, and fungi and from many mineral and animal sources. Some unusual substances, called imponderables, are also used, including electricity, X-ray, and magnetic poles. By convention, the first letter of the Latin-derived name of a remedy is capitalized, and the traditional name is preferred to the chemical or biological name - Natrum muriaticum rather than sodium chloride. Remedies for internal consumption come either as pills or as liquid, and most do not need a doctor's prescription, unless (in the U.S.A.) they are claimed to be for a serious disease such as cancer. Remedies for self-limiting conditions (minor health problems that are expected to go away on their own) can be sold without a prescription.

A characteristic principle of homeopathy is that the efficacy of a remedy can be enhanced by "dynamization" or "potentization". Liquids are diluted (with water or ethanol) and shaken by ten hard strikes against an elastic body ("succussion"), to get the next, higher, potency. Insoluble solids such as oyster shell are diluted by grinding with lactose ("trituration"). Hahnemann used dilutions of 1 part in 100 (centesimal; C potencies), or 1 in 50,000 (quintamillesimal; LM or L potencies); Constantine Hering later introduced Decimal (D or X) potencies, 1 part in 10. Hahnemann advocated 30C dilutions for most purposes (i.e. dilution by a factor of 10030 = 1060). Liquid remedies of such high "potency"' contain just water (but according to homeopaths, the structure of the water has been altered; see memory of water); remedies in pill form contain just sugar.

In many countries, remedies are sold over-the-counter (OTC) in pharmacies and other retail outlets; many of these are "low potencies", i.e. 3X, 3C, 6X, 6C, 12X, and 12C, all of which, except the last, contain some of the original substance. OTC sales of remedies account for 0.3% of a global self-medication market estimated at 48.2 billion dollars. The American Homeopathic Pharmaceutical Association estimated the 1995 retail sales of remedies in the U.S.A. at $201 million and growing at 20% per year. Almost 70% of all OTC remedies are sold in Europe; France is the largest market, worth over 300 million euros in 2003, followed by Germany (200 million euros). In 2007, the U.K market was around £40 million.

In Europe, remedies are occasionally prescribed by MDs, including by 30-40% of French and 20% of German doctors. In France, 35% of the costs of remedies prescribed by an MD are reimbursed from health insurance. The European Union allows remedies to be sold OTC if they are prepared according to the European Pharmacopoeia or the pharmacopoeias used in the Member States, and if they are at least 3X. ; no specific therapeutic indication may be given on the product label.

A typical homeopathic visit
Patients often consult homeopaths with chronic problems that have not responded to conventional treatment; these include common ailments such as eczema, asthma, migraine, irritable bowel syndrome, arthritis, anxiety and depression, but homeopaths also accept patients with serious diseases, including cancer. and AIDS Homeopaths view illness as a disturbance in the 'overall homeostasis of the total being', so they believe that almost any sick person can benefit from homeopathic treatment. Most homeopaths are not medically qualified; those who are, after diagnosing a chronic condition that does not indicate the need for medical urgency, might prescribe a remedy rather than a conventional medicine which they feel may be ineffective and/or likely to have side effects. Homeopaths recognize that trauma might require conventional medical attention, but may complement that with homeopathy.
 * "Homeopathy is designed to treat the whole person and can therefore be considered in almost any situation where a person's health is depleted" (British Homeopathic Association)
 * "The physician must remember that he is treating a patient who has some disorder; he is not prescribing for a disease entity" (American Institute of Homeopathy "Standards of Practice")

In "Classical ("Hahnemannian") homeopathy, a single remedy is chosen according to the physical, emotional, and mental symptoms that the sick individual is experiencing, rather than the diagnosis of a disease ("commercial" homeopathy uses a mixture of remedies in a formula containing individual ingredients chosen by the manufacturer for treating specific ailments). Classical homeopaths place emphasis on the patient's unique symptoms and their psychological state; they gather this information from an interview, typically lasting from 15 minutes to two hours, with one or more follow-up consultations of 15 to 45 minutes. They assess how the patient experiences their disease—i.e. they give priority to the overall syndrome of symptoms and the unique symptoms, unlike the conventional medical approach of trying to identify the causes of the disease. Their goal is to determine factors that might predispose the patient to disease, and find a treatment that will strengthen that patient's "overall constitution". After the interview, the homeopath consults the references described on the right. Some homeopaths make quick prescriptions based on "keynotes" — the best known characteristics of a remedy. The real challenge of homeopathic practice is to find the remedy that best matches the patient's "syndrome of symptoms" — the "similimum".

The homeopathic treatment of acute problems does not need the same depth or breadth of interview as chronic conditions. According to homeopaths, because the symptoms of a common cold or a headache or an allergy vary from person to person, each may need a different remedy. However, they believe that people who experience an injury generally have similar symptoms, so they think that some remedies might be routinely useful in such cases. For some disease conditions, such as asthma or acute bronchitis, remedies are often prescribed not only to treat chronic symptoms, but also to treat acute attacks. Remedies might also be used after an asthmatic episode with the intent to prevent recurrences.

"Classical" homeopaths prescribe one remedy at a time — one that best fits the overall syndrome of the patient. The same remedy might thus be prescribed for patients with very different diseases; conversely, patients suffering from the same disease may be prescribed different remedies. For example, hay fever might be treated with any of several remedies, based either on the specific symptoms or on the etiology of the allergy. Some common remedies are: Allium cepa (onion, which causes tears to flow and a clear burning nasal discharge that irritates the nostrils), Euphrasia (eyebright, which causes a clear and bland nasal discharge along with tears that burn and irritate), Ambrosia (ragweed) and Solidago (goldenrod); ragweed and goldenrod are herbs whose pollen is aggravating to some hay fever sufferers. These are commonly given during the acute symptoms of hay fever. At other times, a homeopath might prescribe a constitutional remedy based on the patient’s family history, health history and overall physical and/or psychological state.

Scientific foundations?
In brief, for homeopathy to receive serious scientific consideration, there must be plausible explanations for:
 * how an ultradiluted solution can have any specific biological activity
 * by what biological mechanism could the specific nature of a remedy be recognised

These demands are often summarised by the maxim "Extraordinary claims require extraordinary proof".

Homeopathy arose when important concepts of modern chemistry and biology, such as molecules and germs, were understood poorly, if at all. In Hahnemann's day, many chemists believed that matter was infinitely divisible, so that it was meaningful to talk about dilution to any degree. The size of atoms was calculated in 1865 (by Josef Loschmidt); we now know that a 12C dilution will have only about one molecule of that drug per litre. Thus, a remedy diluted to more than 12C is virtually certain to contain not a single molecule of the original substance. This is recognized by homeopaths, who assert that the healing power is not in the action of molecules, but in some change in the structure of the water — the presumed "memory of water".

Widely different explanations are proposed. For instance, water contains isotopologues (molecules with different isotopic compositions). Mass spectroscopy can detect these, but the concentration ratios can only be changed by nuclear reactions &mdash; they are not affected by homeopathic treatment. The molecules H2O appear in two proton-spin forms (ortho and para) in a ratio 3:1; these are chemically indistinguishable and very difficult to interconvert. Even if a treatment could give rise to different ortho:para ratios, it requires a massive leap of imagination to envisage how this might result in specific healing qualities. Some homeopaths believe that succussive shaking might lead to "clustering" of water molecules, but motions in liquid water are on the picosecond (10&minus;12 s) timescale and such clusters could not live longer than a few picoseconds. Another suggestion is that double-distilled water contains trace amounts of contaminating ions: water, after vigorous shaking, might include dissolved atmospheric gases as nanobubbles, ions produced from reactions with airborne contaminants, and silicates&mdash;tiny glass "chips"; such contamination is very likely, but it is hard to see how it could have therapeutic value

Homeopaths contend that the "principle of similars" is analagous to the concept of hormesis and is the basis for vaccination and allergy desensitation. Scientists do not think that this 'principle' is generally true or useful, and they explain vaccination without it. Although remedies and vaccinations both use low doses, the doses in remedies are very much lower than those in vaccines. Vaccines produce a measurable immune response (e.g., immunoglobulin production); remedies do not. Thus conventional treatments involve measurable doses of substances, at levels known to activate a cellular response.

Homeopaths assert that they are up against a 'double standard'. Many conventional treatments were used before any knowledge of their mechanism of action; only recently, for instance, has it been understood how aspirin works. Aspirin was introduced at the turn of the 20th century, and medical standards have become very much more rigorous since then. If aspirin was a new drug, it would require clinical trials; Institutional Review Boards demand that the mechanism of action be known before authorizing these.

Efficacy
Homeopaths assert that trials of efficacy, basic sciences research, historical use of remedies in infectious disease epidemics, and cost-effectiveness studies provide good evidence for the benefits of homeopathy. They favour the evidence of their experience in treating patients; they also (correctly) state that most published trials have reported evidence for some benefits, including for postoperative ileus, allergic rhinitis , and childhood diarrhoea Homeopathy also scores more highly in "patient satisfaction" surveys than conventional primary care; this is attributed to the greater empathy shown by homeopaths towards their patients, and to the existence of "effectiveness gaps", chronic conditions where conventional therapies are not available or not effective, and which are then overrepresented among patients of homeopaths.

According to academic critics, trials of homeopathy have mostly been small and flawed (lacking adequate controls and objective outcome measures). A 1991 meta-analysis in the British Medical Journal of 105 homeopathic trials recognised that most showed positive results, but warned that "most trials are of low methodological quality." A 1997 meta-analysis in the Lancet also noted the preponderance of positive trial results, stating that the results were "not compatible with the hypothesis that the effects of homoeopathy are completely due to placebo." However, the same authors went on to show that larger high-quality trials tend to show little or no significant effects The most recent meta-analyses, which take study quality into account, suggest that remedies are no different to placebos.

Why small trials tend to report positive outcomes while large trials are more likely to report small or no effects is generally attributed to "publication bias"; small trials with negative or inconclusive outcomes are less likely to be written up for publication, and if submitted are less likely to be accepted for publication, because they are thought to be uninteresting. In 1999, the Swiss Government, for 5 years, allowed costs for treatment with homeopathy and four other CAM modalities to be reimbursed by the country’s health insurance scheme, and set out to evaluate their cost-effectiveness. A team of scientists and practitioners, including a homeopath, conducted a meta-analysis that aroused a storm of protest from homeopaths. The study, published in the Lancet took a novel approach; while traditional meta-analyses combine studies of a single condition, this analysis tested the hypothesis that all effects of homeopathy are placebo effects. If so, the authors reasoned, then the predominance of positive reports reflects publication bias, and hence the magnitude of effects should diminish with sample size and study quality. They analyzed 110 placebo-controlled homoeopathy trials and 110 matched conventional trials. In both, effect size declined with improved study quality; however, some effect was still present in the largest and best conventional trials, but not in the largest and best homeopathy trials. The authors concluded that homeopathy was no better than placebo, and that no further research on homeopathy was necessary. The article was accompanied by two editorials, one titled “The end of homeopathy”. .

Homeopathic response
The Lancet published critical correspondence, and received an open letter from the 'Swiss Association of Homoeopathic Physicians' :

"'The meta-analysis may be statistically correct. But its validity and practical significance can be seen at a glance: not one single qualified homoeopath would ever treat one single patient in clinical practice as presented in any of the 110 analysed trials! The study cannot give the slightest evidence against homoeopathy because it does not measure real individual (classical) homoeopathy. It confounds real homoeopathic practice with distorted study forms violating even basic homeopathic rules.'"

Several studies that had been defined as "high quality" by Linde et al. (1997) were not defined by high quality in the Lancet paper by Shang et al., and most of these showed an effect of homeopathic treatment. Shang et al. also excluded a relatively large study of chronic polyarthritis (N=176) because no matching trial could be found. An article in the Journal of Clinical Epidemiology stated "This result can be interpreted differently. Following Shang's perspective it can be explained by small study bias (which includes publication bias). In contrast, one may hypothesize that Shang's result is falsely negative." The authors noted that four of the 21 'best' trials dealt with muscle soreness; these found no benefits to homeopathy, but the other 17 trials show an overall significant effect, mainly determined by two trials on influenza-like diseases. Thus, they argue, homeopathy might be effective for some conditions but not others.

Homeopaths believe that, because homeopathy does not lend itself to controlled trials, those with a negative outcome may be false negatives. They also claim that many studies in which homeopathy appears ineffective are methodologically flawed &mdash; they either did not follow proper homeopathic procedure in the selection of remedies or they did not adequately repeat the remedy.

Government and institutional assessments
In 2010, the U.K. House of Commons 'Science and Technology Committee' published a report on homeopathy. It concluded that the principle of "like-cures-like" is theoretically weak, and "fails to provide a credible physiological mode of action for homeopathic products. We note that this is the settled view of medical science." It described the use of ultra-dilution as scientifically implausible, and on the effectiveness of homeopathy said:

"'In our view, the systematic reviews and meta-analyses conclusively demonstrate that homeopathic products perform no better than placebos'"

The report rejected evidence presented by the British Homeopathic Association on systematic reviews and accepted Professor Edzard Ernst's account of the weaknesses of that evidence. It stated that advocates of homeopathy had chosen "to rely on, and promulgate selective approaches to the evidence base". It rejected calls for further research:

"'There has been enough testing of homeopathy and plenty of evidence showing that it is not efficacious. Competition for research funding is fierce and we cannot see how further research on the efficacy of homeopathy is justified'"

It recommended against the use of homeopathy on the NHS even as a placebo treatment: for a placebo to be effective, the patient must not know it is a placebo, but medical ethics requires that a patient must make an informed choice. It also advised that, if the NHS appears to endorse homeopathy, there is a danger that patients might neglect conventional medicine, with serious health consequences. The report concludes that NHS funding of homeopathic hospitals should stop, and that NHS doctors should not refer patients to homeopaths.

The report is endorsed by the British Medical Association, which voted in favour of stopping any use of any NHS funds for homeopathy, and proposed that pharmacists should remove homeopathic remedies from their shelves to prevent them from being confused with medicines.

The Royal Pharmaceutical Society of Great Britain suggested that patients ought to be made aware that there is no scientific basis for the use of homeopathy, and that unless homeopathy can be shown to be efficacious "using appropriate methodology (as for conventional medicines)" any claims of efficacy should be removed from the label. It also concluded that "homeopathic remedies should be reviewed by the National Institute for Clinical Excellence (NICE) if they are to be used within the NHS" – historically, homeopathy has not been subject to review by NICE. The U.K. Government, for now, continues to allow doctors to prescribe homeopathic treatment on the NHS in linewith the principle that they should be free to decide whatever treatment they think appropriate in individual cases.

Medical organizations' attitudes
The American Medical Association (AMA) was founded in 1847 and from the 1860s to the early 20th century it forbade its members to consult with MDs who practiced homeopathy. Today it is not openly antagonistic to homeopathy; their policy states: "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." The National Center for Complementary and Alternative Medicine (NCCAM) funds research into alternative medicine in the U.S.A. . Their views on homeopathy are detailed here; in 2008, their acting deputy director said "There is, to my knowledge, no condition for which homeopathy has been proven to be an effective treatment."

In the U.K., the NHS recognizes that there have been about 200 randomised controlled trials evaluating homeopathy, and concludes "it has proven difficult to produce clear clinical evidence that homeopathy works". Its doctors are free to decide what treatment is best for each patient, and a few do sometimes prescribe homeopathic remedies. The NHS supports five homeopathic hospitals, and in Scotland about 600 doctors treat about 55,000 patients per year at homeopathic clinics. In 2007, doctors in the U.K. issued 49,300 prescriptions for homeopathic remedies out of a total of 796 million prescriptions (down from 83,000 in 2005). In 2008, it was reported that the NHS was progressively withdrawing funding for homeopathic treatments because of doubts about efficacy.

Safety
"'The highest ideal of cure is the speedy, gentle, and enduring restoration of health by the most trustworthy and least harmful way' (Samuel Hahnemann)"

In the U.S.A., the FDA determines what drugs are safe for OTC sale; its view is that there is no real concern about the safety of homeopathic remedies because of the extremely small dosages, and the vast majority do not need a doctor's prescription. However, some physicians maintain that homeopathic treatment is unsafe, because it might delay other treatment/s. The concern is greatest when patients forego conventional treatment for serious illness (such as anti-inflammatories and bronchodilators for asthma), or do not receive established preventive treatments (such as vaccines or anti-malarial drugs).

Most drugs of the 19th century were at best ineffective and often dangerous; even in 1860 Oliver Wendell Holmes declared that, (with a few exceptions) "if the whole materia medica, as now used, could be sunk to the bottom of the sea, it would be better for mankind-and all the worse for the fishes." However, some homeopaths question whether modern medicines are safe and effective, and remind patients and physicians of the Hippocratic aphorism "First, do no harm".

Many homeopaths think that vaccination for diseases such as measles is unnecessary, and that vaccines can be damaging, because of the mercury and aluminum in them, because the bacterium or virus in the vaccine may neither be dead nor weak enough, and/or because some childhood infections may strengthen immune responsiveness. Such advice is considered irresponsible by public health professionals, who assess the benefits of vaccination as vastly outweighing the risks. For example, measles is not a major killer in the western world, where most children are vaccinated, but in 1999 it caused 875,000 deaths worldwide, mostly in Africa. In 2001, a "Measles Initiative" was begun by the American Red Cross, UNICEF and the World Health Organization; by 2005 more than 360 million children had been vaccinated, and the death toll had dropped to 345,000.

Regulation
There are no universal standards for homeopathic education. Some countries allow homeopaths to describe themselves in equivalent ways to doctors, with a system of qualification and oversight; in others (including France, Spain and Argentina) most professionals that prescribe remedies are MDs Some countries (including India and Pakistan) have exclusively homeopathic medical schools, some (including Germany) have naturopathic colleges homeopathy is part of the curriculum, and some certify "professional homeopaths" who have attended homeopathic schools and then pass examinations that grant "certification" as homeopaths. In the U.S.A., there is also a separate certification process available only to MDs and DOs, and naturopathic physicians also have a homeopathic certifying agency. To join the American Institute of Homeopathy today, a mainstream medical license (MD, DO, DDS) is required as well as homeopathic training.

In India, homeopathy has more than 200,000 registered practitioners and is one of the Indian "National Systems of Medicine" under the Department of AYUSH (Ayurveda, Yoga and Naturopathy, Unani, Siddha and Homeopathy); it is illegal to practice as a homeopath without a license and professional qualifications. Every Indian primary health care centre has one or more conventional doctors and a doctor from the Department of AYUSH. About 10% of the population, over 100 million people, depend solely on homeopathy for their health care needs.

In the UK, anyone can declare themselves to be a homeopath and practice without any qualification Most homeopaths are not medically-trained, and many of these belong to the Society of Homeopaths, a European-wide organisation. The Society keeps a register of professionally trained and insured homeopaths who agree to abide by the Society's Code of Ethics and Practice. However, unlike other major CAM professions, homeopathy still has no statutory regulation process. Some laws apply: for example, the 1939 Cancer Act makes it illegal to claim to have an effective treatment for cancer if it isn't actually an effective treatment, and this is enforced by the Trading Standards Office. Beyond that, the same regulations apply to homeopaths as to any commercial operation - such as the Sale of Goods Act, and the Advertising Standards Authority. Advertisments for homeopathy must include the instruction to "to consult a doctor if symptoms persist".

In the UK, the Faculty of Homeopathy regulates medical professionals who practice homeopathy. It publishes the journal Homeopathy, and is a founding member of the 'European Committee for Homeopathy' which has developed a code of professional conduct. Of 248,000 registered practitioners of medicine in the U.K., only about 400 are members of the Faculty. Homeopaths with medical qualifications have, on occasion, been disciplined by the General Medical Council for using homepathic remedies inappropriately but not by the Faculty, which has no means of enforcing its code.