Homeopathy ("home-ee-AH-pah-thy") is a form of health care that
developed in Germany and has been practiced in the United States
since the early 19th
Homeopathic practitioners are commonly called homeopaths. This fact
sheet answers some frequently asked questions on homeopathy and
reviews scientific research on its use and effectiveness.
The term homeopathy comes from the Greek words homeo,
meaning similar, and pathos, meaning suffering or disease.
Homeopathy is an alternative medical system. Alternative medical
systems are built upon complete systems of theory and practice, and
often have evolved apart from and earlier than the conventional
medical approach used in the United States. Homeopathy takes a different
approach from conventional medicine in diagnosing, classifying, and
treating medical problems.
Key concepts of homeopathy include:
- Homeopathy seeks to stimulate the body's defense
mechanisms and processes so as to prevent or treat
- Treatment involves giving very small doses of
substances called remedies that, according to homeopathy, would
produce the same or similar symptoms of illness in healthy people
if they were given in larger doses.
- Treatment in homeopathy is individualized (tailored
to each person). Homeopathic practitioners select remedies
according to a total picture of the patient, including not only
symptoms but lifestyle, emotional and mental states, and other
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In the late 1700s, Samuel Hahnemann, a physician, chemist, and
linguist in Germany, proposed a new approach to treating illness.
This was at a time when the most common medical treatments were
harsh, such as bloodletting,c
purging, blistering, and the use of sulfur and mercury. At the time,
there were few effective medications for treating patients, and
knowledge about their effects was limited.
Hahnemann was interested in developing a less-threatening
approach to medicine. The first major step reportedly was when he
was translating an herbal text and read about a treatment (cinchona
bark) used to cure malaria. He took some cinchona bark and observed
that, as a healthy person, he developed symptoms that were very
similar to malaria symptoms. This led Hahnemann to consider that
a substance may create symptoms that it can also relieve. This
is called the "similia principle" or "like cures like." The similia
principle had a prior history in medicine, from Hippocrates in
Ancient Greece--who noted, for example, that recurrent vomiting
could be treated with an emetic (such as ipecacuanha) that would
be expected to make it worse--to folk medicine. Another way to view "like
cures like" is that symptoms are part of
the body's attempt to heal itself--for example, a fever can develop
as a result of an immune response to an infection, and a cough may
help to eliminate mucus--and medication may be given to support this
Hahnemann tested single, pure substances on himself and, in more
dilute forms, on healthy volunteers. He kept meticulous records of
his experiments and participants' responses, and he combined these
observations with information from clinical practice, the known uses
of herbs and other medicinal substances, and toxicology,
eventually treating the sick and developing homeopathic clinical
Hahnemann added two additional elements to homeopathy:
- A concept that became "potentization," which holds that
systematically diluting a substance, with vigorous shaking at each
step of dilution, makes the remedy more, not less, effective by
extracting the vital essence of the substance. If dilution
continues to a point where the substance's molecules are gone,
homeopathy holds that the "memory" of them--that is, the effects
they exerted on the surrounding water molecules--may still be
- A concept that treatment should be selected based upon a total
picture of an individual and his symptoms, not solely upon
symptoms of a disease. Homeopaths evaluate not only a person's
physical symptoms but her emotions, mental states, lifestyle,
nutrition, and other aspects. In homeopathy, different people with
the same symptoms may receive different homeopathic remedies.
Hans Burch Gram, a Boston-born doctor, studied homeopathy in
Europe and introduced it into the United States in 1825. European
immigrants trained in homeopathy also made the treatment
increasingly available in America. In 1835, the first homeopathic
medical college was established in Allentown, Pennsylvania. By the
turn of the 20th century, 8 percent of all American medical
practitioners were homeopaths, and there were 20 homeopathic medical
colleges and more than 100 homeopathic hospitals in the United
In the late 19th and early 20th centuries, numerous medical
advances were made, such as the recognition of the mechanisms
disease; Pasteur's germ theory; the development of antiseptic
techniques; and the discovery of ether anesthesia. In addition, a
report (the so-called "Flexner Report") was released that triggered
major changes in American medical education. Homeopathy was among
the disciplines negatively affected by these developments. Most
homeopathic medical schools closed down, and by the 1930s others
converted to conventional medical schools.
In the 1960s, homeopathy's popularity began to revive in the
United States. According to a 1999 survey of Americans and their
health, over 6 million Americans had used homeopathy in the
preceding 12 months.
The World Health Organization noted in 1994 that homeopathy had been
integrated into the national health care systems of numerous
countries, including Germany, the United Kingdom, India, Pakistan,
Sri Lanka, and Mexico.
Several schools of practice exist within homeopathy.
Persons using homeopathy do so to address a range of health
concerns, from wellness and prevention to treatment of injuries,
diseases, and conditions. Studies have found that many people who
seek homeopathic care seek it for help with a chronic medical
Many users of homeopathy treat themselves with homeopathic products
and do not consult a professional.
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In European countries, training in homeopathy is usually pursued
either as a primary professional degree completed over 3 to 6 years
or as postgraduate training for doctors.
In the United States, training in homeopathy is offered through
diploma programs, certificate programs, short courses, and
correspondence courses. Also, homeopathic training is part of
medical education in naturopathy. Most homeopathy in the United States
is practiced along with another health care practice for which
the practitioner is licensed, such as
conventional medicine, naturopathy, chiropractic, dentistry,
acupuncture, or veterinary medicine (homeopathy is used to treat
Laws about what is required to practice homeopathy vary among
states. Three states (Connecticut, Arizona, and Nevada) license
medical doctors specifically for homeopathy.
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Typically, in homeopathy, patients have a lengthy first visit,
during which the provider takes an in-depth assessment of the
patient. This is used to guide the selection of one or more
homeopathic remedies. During followup visits, patients report how
they are responding to the remedy or remedies, which helps the
practitioner make decisions about further treatment.
Most homeopathic remedies are derived from natural substances
that come from plants, minerals, or animals.. Homeopathy asserts
that this process can maintain a
substance's healing properties regardless of how many times it has
been diluted. Many homeopathic remedies are so highly diluted that
not one molecule of the original natural substance remains.
Remedies are sold in liquid, pellet, and tablet forms.
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Because of their long use in the United States, the U.S. Congress
passed a law in 1938 declaring that homeopathic remedies are to be
regulated by the FDA in the same manner as nonprescription,
over-the-counter (OTC) drugs, which means that they can be purchased
without a physician's prescription. Today, although conventional
prescription drugs and new OTC drugs must undergo thorough testing
and review by the FDA for safety and effectiveness before they can
be sold, this requirement does not apply to homeopathic remedies.
Remedies are required to meet certain legal standards for
strength, quality, purity, and packaging. In 1988, the FDA required
that all homeopathic remedies list the indications for their
(i.e., the medical problems to be treated) on the label.The FDA also
requires the label to list ingredients, dilutions, and instructions
for safe use.
The guidelines for homeopathic remedies are found in an official
guide, the Homeopathic Pharmacopoeia of the United States,
which is authored by a nongovernmental, nonprofit organization of
industry representatives and homeopathic experts.
The Pharmacopoeia also includes provisions for testing new
remedies and verifying their clinical effectiveness. Remedies on the
market before 1962 have been accepted into the Homeopathic
Pharmacopoeia of the United States based on historical use,
rather than scientific evidence from clinical trials.
The FDA has learned of a few reports of illness associated with
the use of homeopathic remedies. However, the FDA reviewed these
reports and decided that the remedies were not likely to be the
cause, because of the high dilutions.
Here is some general information that has been reported about
risks and side effects in homeopathy:
- Homeopathic medicines in high dilutions, taken under the
supervision of trained professionals, are considered safe and
unlikely to cause severe adverse reactions.
- Some patients report feeling worse for a brief period of time
after starting homeopathic remedies. Homeopaths interpret this as
the body temporarily stimulating symptoms while it makes an effort
to restore health.
- Liquid homeopathic remedies can contain alcohol and are
permitted to have higher levels of alcohol than conventional drugs
for adults. This may be of concern to some consumers. However, no
adverse effects from the alcohol levels have been reported either
to the FDA or in the scientific literature.
- Homeopathic remedies are not known to interfere with
conventional drugs; however, if you are considering using
homeopathic remedies, you should discuss this with your health
care provider. If you have more than one provider, discuss it with
As with all medicinal products, a person taking a homeopathic
remedy is best advised to:
- Contact his health care provider if his symptoms continue
unimproved for more than 5 days.
- Keep the remedy out of the reach of children.
- Consult a health care provider before using the product if the
user is a woman who is pregnant or nursing a baby.
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This section summarizes results from (1) individual clinical
trials (research studies in people) and (2) broad analyses of groups
of clinical trials.
The results of individual, controlled clinical trials of
homeopathy have been contradictory. In some trials, homeopathy
appeared to be no more helpful than a placebo; in other studies,
some benefits were seen that the researchers believed were greater
than one would expect from a placebo.
Systematic reviews and meta-analyses take a broader look at
collections of a set of results from clinical trials. In sum, systematic
reviews have not found homeopathy to be a definitively proven treatment
for any medical condition. Two groups
of authors found some positive evidence in the groups of studies
they examined, and they did not find this evidence to be explainable
completely as placebo effects (a third group found 1 out of 16
trials to have some added effect relative to placebo). Each author
or group of authors criticized the quality of evidence in the
studies. Examples of problems they noted include weaknesses in
design and/or reporting, choice of measuring techniques, small
numbers of participants, and difficulties in replicating results.
A common theme in the reviews of homeopathy trials is that because
these problems and others, it is difficult or impossible to draw
firm conclusions about whether homeopathy is effective for any
single clinical condition.
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Yes. Homeopathy is an area of complementary and alternative
medicine (CAM) that has seen high levels of controversy and debate,
largely because a number of its key concepts do not follow the laws
of science (particularly chemistry and physics).
- It is debated how something that causes illness might also
- It has been questioned whether a remedy with a very tiny
amount (perhaps not even one molecule) of active ingredient could
have a biological effect, beneficial or otherwise.There
have been some research studies published on the use of ultra-high
dilutions (UHDs) of substances, diluted to levels compatible with
those in homeopathy and shaken hard at each step of dilution.
The results are claimed to involve phenomena at the molecular
level and beyond, such as the structure of water, and waves and
fields. Both laboratory research and clinical trials have been
published. There have been mixed results in attempts to replicate
them. Reviews have not found UHD results to be definitive or
There have been some studies that found effects of UHDs on
isolated organs, plants, and animals.
There have been controversy and debate about these findings as
- Effects in homeopathy might be due to the placebo or other
- There are key questions about homeopathy that are yet to be
subjected to studies that are well-designed--such as whether it
actually works for some of the diseases or medical conditions for
which it is used, and if so, how it might work.
- There is a point of view that homeopathy does work, but that
modern scientific methods have not yet explained why. The failure
of science to provide full explanations for all treatments is not
unique to homeopathy.
- Some people feel that if homeopathy appears to be helpful and
safe, then scientifically valid explanations or proofs of this
alternative system of medicine are not
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CAM on PubMed
U.S. Food and Drug Administration (FDA)
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