The history
From a German doctor's dose of bark in 1790 to one of India's official systems of medicine, tested along the way by chemistry and clinical trials.
Around 1800, medicine often meant bleeding and harsh purges. A German doctor, Samuel Hahnemann, proposed a gentler system built on "like cures like" and tiny doses. It spread across Europe and the Americas, and above all to India, where it became an official, regulated system with its own colleges and research council. Meanwhile chemistry showed that high dilutions contain no molecules of the starting substance, and large reviews of fair tests found no reliable evidence that it works better than placebo. Homeopaths dispute those reviews, and the debate continues.
1790
Cinchona self-experiment
Samuel Hahnemann, Germany
1796
Founding essay on the "new principle"
Samuel Hahnemann, Germany
1810
The Organon
Samuel Hahnemann, Germany
1829–1839
Homeopathy reaches the Indian subcontinent
J. M. Honigberger, Lahore
1844
First national medical society in the US
American Institute of Homeopathy
1881
Major homeopathy college in India
Calcutta Homoeopathic Medical College
1978
Government research council for homeopathy
CCRH, India
400 BCE – 1789
The idea that "like" might cure "like" appears here and there, while mainstream medicine relies on bleeding, purging and blistering.
400 BCE
c. 400 BCE
Some texts in the Hippocratic collection are said to note that certain illnesses can be eased by things that cause similar symptoms. The Swiss physician Paracelsus voiced a similar idea in the 1500s. It was one idea among many, not a system.
Why it mattered. Hahnemann would later turn this old hint into the centre of a whole system of medicine.
1755
10 April 1755
Hahnemann was born into a family of porcelain painters. He studied medicine in Leipzig, Vienna and Erlangen, and spoke many languages, which later let him earn a living as a translator.
Why it mattered. His skill as a translator put him in front of the book that started homeopathy.
1784
c. 1784
Hahnemann gave up medical practice, writing that the treatments of the day could make a doctor a danger to his patients. He supported his family by translating medical and chemistry books.
Why it mattered. His dislike of harsh treatment explains much of homeopathy's gentle approach.
1799
December 1799
As George Washington lay ill with a throat infection, his doctors drained an estimated 2.4 litres of his blood in about 12 hours, around 40% of the total. He died that night. Estimates vary.
Why it mattered. Next to "heroic" treatments like this, gentle remedies that did no harm looked very attractive.
1790 – 1843
Hahnemann tests cinchona bark on himself, writes the Organon and builds homeopathy: similars, provings, single remedies and ever-higher dilutions.
1790
Translating William Cullen's Materia Medica, Hahnemann doubted Cullen's explanation of why cinchona bark treats malaria fever. He took the bark himself while healthy and reported fever-like symptoms. Later repeats did not reliably produce the same effect.
Why it mattered. This self-test gave him the idea that "like cures like".
1796
Hahnemann published his "Essay on a New Principle for Ascertaining the Curative Powers of Drugs" in a leading German medical journal, arguing that drugs should be tested on healthy people and used for similar symptoms.
Why it mattered. This is usually counted as homeopathy's founding paper.
1807
Hahnemann first used the term, from the Greek for "similar" and "suffering", in an essay in Hufeland's Journal. He also coined "allopathy" for ordinary medicine.
Why it mattered. The name stuck, and so did the split between the two words.
1810
Hahnemann set out his full system in "Organon der rationellen Heilkunde": like cures like, provings on healthy people, one remedy at a time and the smallest dose. He revised it five times.
Why it mattered. The Organon is still the core text taught in homeopathy colleges, including India's BHMS course.
1820
Two French chemists extracted quinine, the substance in cinchona bark that kills the malaria parasite. Quinine became a standard malaria drug.
Why it mattered. It showed that the bark works through a real chemical, not by causing similar symptoms.
1829 – 1947
Homeopathy spreads across Europe and the Americas and reaches India through Lahore and Bengal, while science begins counting molecules.
1829
1829–1839
Honigberger, a doctor from Transylvania, reached Lahore in 1829 and later returned at Maharaja Ranjit Singh's request. Accounts say he treated the Maharaja with a homeopathic remedy around 1839. Details come mostly from his own memoir.
Why it mattered. He is usually named as the person who brought homeopathy to the Indian subcontinent.
1831
1831–1832
When cholera swept Europe, homeopathic hospitals reported fewer deaths than hospitals using bleeding and purges. Historians note the records are hard to compare, and avoiding harmful treatment may explain much of the difference.
Why it mattered. The reports helped homeopathy spread fast across Europe and to India.
1844
Homeopaths founded the American Institute of Homeopathy, three years before the American Medical Association. Homeopathy became popular in the US in the 1800s.
Why it mattered. Homeopathy was once part of mainstream medicine in several countries.
1865
Loschmidt made the first estimate of the size of molecules and how many there are in a given amount of gas. This led to Avogadro's number, 6.022 × 10²³.
Why it mattered. It made it possible to show that high dilutions like 30C hold no molecule of the starting substance, something Hahnemann could not have known.
1867
c. 1867
Mahendralal Sircar, one of the first MD graduates of Calcutta University, publicly declared his support for homeopathy after being introduced to it by Rajendralal Dutta. He later founded the Indian Association for the Cultivation of Science (1876).
Why it mattered. His support gave homeopathy standing among educated Bengalis.
1897
Kent published a huge index of symptoms, each listing remedies graded by type. It became the most used repertory in classical homeopathy, including in India.
Why it mattered. It is still the model for how homeopaths look up a remedy, now often in software.
1921
The 6th edition of the Organon, which Hahnemann finished in 1842, was published at last. It describes the LM (1 in 50,000) potencies.
Why it mattered. Indian colleges teach this final edition.
1947 – today
India builds laws, colleges, a research council and a ministry for homeopathy alongside its other systems of medicine.
1978
30 March 1978
The Central Council for Research in Homoeopathy was set up to run research on homeopathy, including drug provings, drug standards and clinical studies. It now has institutes across India.
Why it mattered. Few countries have a government research council devoted to homeopathy.
2014
9 November 2014
The department for Indian systems of medicine and homeopathy became a full ministry: AYUSH, for Ayurveda, Yoga and Naturopathy, Unani, Siddha, Sowa-Rigpa and Homoeopathy.
Why it mattered. Homeopathy sits beside Ayurveda, Unani and Siddha as an official system in India.
2020
September 2020
A new law replaced the Central Council with the National Commission for Homoeopathy, which came into force on 5 July 2021. It regulates homeopathy colleges and the register of practitioners.
Why it mattered. India now has more than 3.45 lakh registered homeopathy practitioners.
1988 – today
Blinded experiments, large reviews and health services test homeopathy's claims. Most find no effect beyond placebo; homeopaths dispute them.
1988
30 June 1988
Benveniste's team reported that antibody solutions diluted far past 12C still affected blood cells. Nature published it with a warning, then sent a team that watched the tests repeated blind: the effect vanished. Later labs could not repeat it either.
Why it mattered. It remains the best-known attempt to show how a remedy with no molecules could act.
2005
27 August 2005
The analysis compared 110 homeopathy trials with 110 matched trials of ordinary medicine. In the larger, better-run trials, homeopathy's effects were compatible with placebo, while ordinary medicine's were not. Homeopaths criticised how trials were chosen.
Why it mattered. It was one of the most cited studies in the debate about homeopathy.
2009
August 2009
Answering young scientists, WHO officials said they do not recommend homeopathy for HIV, TB, malaria, influenza or infant diarrhoea.
Why it mattered. Delaying proven treatment for these diseases can be deadly.
2010
Researchers at IIT Bombay reported tiny particles of the starting metal in some commercial high-potency metal remedies. The idea has not been independently confirmed as a way remedies act, and it does not cover plant remedies.
Why it mattered. It is one of the Indian research lines homeopaths cite, still debated.
2015
March 2015
After looking at 176 studies across 61 conditions, the NHMRC concluded there were no health conditions with reliable evidence that homeopathy was effective. Homeopathy groups disputed its methods; the NHMRC stood by its findings.
Why it mattered. It is the most-cited government review of homeopathy.
2017
November 2017
After a public consultation, NHS England told local health bodies to stop routinely prescribing homeopathy, citing a lack of robust evidence. The High Court rejected a challenge in 2018.
Why it mattered. One of the health services where homeopathy had the longest history stepped back from it.
Did you know?
Hahnemann died in 1843, 22 years before anyone first estimated how many molecules a substance holds.
A 30C remedy is diluted 1 in 10⁶⁰. To expect one molecule you would need about 10¹⁵ Earth oceans of it.
India has more than 3.45 lakh registered homeopathy practitioners, one of the largest numbers in the world.
The American Institute of Homeopathy, founded in 1844, is older than the American Medical Association.
The people
1755 – 1843 · Physician and translator · Germany
Founded homeopathy and wrote the Organon.
1800 – 1878 · Painter and homeopath · France
Hahnemann's second wife; practised homeopathy in Paris and kept his last Organon.
1795 – 1869 · Physician · Transylvania (Romania)
Brought homeopathy to the court of Maharaja Ranjit Singh in Lahore.
1833 – 1904 · Physician and science builder · India
Leading Calcutta doctor who backed homeopathy and founded the IACS.
1851 – 1922 · Homeopath and teacher · India
Co-founded the Calcutta Homoeopathic Medical College in 1881.
1849 – 1916 · Homeopath · United States
Wrote the repertory still used by homeopaths.
1821 – 1895 · Physicist and chemist · Austria
First estimated how many molecules a substance contains.
1935 – 2004 · Immunologist · France
Reported "water memory" in 1988; the result could not be repeated blind.
Where it happened
Sources
Dates marked “c.” are approximate, and historians sometimes disagree about who was first. If you spot a mistake, tell us.
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