The Human Truth Foundation

Does Homeopathy Work? What are the Risks and Dangers?

By Vexen Crabtree 2015

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#acupuncture #alternative_therapies #chiropractic #color_therapy #herbalism #homeopathy #phrenology #placebo_effect #pseudoscience #quantum_physics

Homeopathy is one of the biggest alternative-medicine industries, and as a result of its infamy it has been heavily studied. The conclusions of these studies is that homeopathy itself does not work1,2,3,4 and only poorly controlled experiments are more likely to show that it works5. It is founded on confused and nonsensical ideas that have been proven to be false, and products can have unexpected side-effects6. Homeopathic solutions are prepared through a series of dilutions that are so pronounced (30C) that not a single molecule of any active ingredient is found in the resultant water - the full dilution rate for a standard preparation of 30 dilutions of 1 drop in 100 is one in 1,000,​000,000,​000,000,​000,000,​000,000,​000,000,​000,000,​000,000,​000,000,​000,000,​0007,4. The theory is that the water has "memory", that diluting the chemical makes the cure stronger, and that this memory is somehow what cures disease. The original solution is sometimes based on a "like cures like" principal, whereby a chemical that causes similar symptoms is used, and other potions are based on the same type of basic thinking as found in herbalism. It works only by psychological side-effects8, and is akin to confidence-trickery, and as such Homeopathy works best on illnesses that have a strong psychological component, and on illnesses that come and go naturally no matter what interventions you make, like the common cold. Dr Ben Goldacre notes that "Homeopaths [... talk] about 'aggravations', explaining that sometimes the correct remedy can make symptoms get worse before they get better, and claiming that this is part of the treatment process. [...] Literally anything that happens to you after a treatment is proof of the therapist's clinical acumen and prescribing skill"9. Because people do not understand concepts such as statistical regression (most illnesses get worse then get better, all on their own) nor the placebo effect (the power of positive thinking on the body), many people are tricked into thinking that homeopathy works.1,2,5. Also, as most people don't understand what homeopathy is, many products are sold simply without the customer realizing that they're not buying medicine and that the products have not been tested to the same standards as medical products8.

1. An Introduction to Alternative Therapies in General

#alternative_therapies #pseudoscience #USA

In the USA up to 4 in ten adults use 'some form' of alternative therapy10. In Britain there are about 150 000 alternative therapists, and the public spend about £4.5 billion on them (as of year 2009)11. In nearly all practices, they work due to the psychology surrounding 'treatment' (the placebo effect and statistical regression) rather than the actual result of the treatment. This is why drugs companies spend more on branding and advertising than they do on research and development12. Nearly all alternative therapies are psychological trickery rather than real medicine13. All such practices are called quackery by skeptics. The danger is that many people seek help from 'alternative' providers before they seek proper medical help, which can result in delayed treatment and in the worst cases, death from ailments that are otherwise perfectly curable if only the sufferer had gone to a normal doctor sooner10. "Some homeopathic remedies may contain substances that are not safe, or that interfere with the action of other medicines" and a real doctor should be consulted before using alternative therapies14 (including those that say they are 'natural' - so are many poisons).

"Pseudoscience and Health: The World of Alternatives (to Truth)" by Vexen Crabtree (2014)

2. Homeopathy's Dubious and Misguided Beginnings 15

#history #homeopathy #medicine

Just beginning a career in medicine in 1781, Samuel Hahnemann, an idealistic young German physician, quickly became disillusioned with the medicine of his day [for example] the treatment of malaria with cinchona bark, or quinine. Curious, he experimented with it on himself, and experienced symptoms similar to those of malaria. It was a turning point in his life. On the basis of this single personal anecdote, he declared the Law of Similars: "Like cures like," or similia, similabus, curantor. A substance that causes certain symptoms in a healthy person, he concluded, could be used to treat illnesses that have the same symptoms. [...]

[He] began experimenting with all kinds of natural substances, attempting to match up the symptoms they induced in healthy people with the symptoms of various illnesses. Unfortunately, some of the side effects associated with the use of these substances were serious [so] in an effort to reduce the severity of the side effects, he took the rather obvious step of diluting the medicine. As you would expect, dilution reduced the side effects, but to his astonishment Hahnemann also observed that patients given the dilute medication recovered more quickly from their illness. At that point, you and I might have concluded that the medicine was preventing them from getting better. [...]

Hahnemann attributes healing to a spiritual "medicinal energy," which he says is most powerful "when it communicates nothing material." He wrote, for example, that smallpox and measles can be transmitted from one child to another without anything material being passed, comparing it to the force a magnet exerts on a needle it does not touch. This is "vitalism," the belief that life involves some spiritual essence beyond chemistry or physics. It was the prevailing medical superstition of the time. [...]

Fortunately for Hahnemann´s patients, the Law of Infinitesimals cancelled the Law of Similars. Your baby has diaper rash? Dr. Hahnemann´s prescription, based on the Law of Similars, would be to treat baby with something that causes a rash. He prescribed the herb Rhus toxicodendrum, more commonly known as poison ivy. Fortunately for baby, the Law of Infinitesimals calls for a 30C dilution of rhus toxicodendrum, more than enough to ensure that not a single molecule of the toxin could remain in the medication. If the affected area is kept clean and dry for a few days, the diaper rash will disappear - and homeopathy will be credited with another success. [...]

Hahnemann´s Organon of the medical Art even specified exactly how many times the solution was to be shaken between subsequent dilutions (four). Homeopathy today is still practiced straight out of Hahnemann´s two-hundred-year-old Organon.

"Superstition: Belief in the Age of Science" by Robert L. Park (2008)8

Medicine has come on a long, long way since the 18th century.

Since it was written, the assumptions on which homeopathy is based have been totally refuted. [...] Scientific discoveries in Europe and Britain were about to alter the landscape. [...] The germ theory of disease, emerging from the work of Pasteur and Koch after the death of Darwin, would prove to be the death of such superstitious nonsense as vitalism and such appalling treatments as bleeding and purgatives. [... Now, ] Avogadro´s number has been measured to five significant figures, and most diseases have been found to be caused by germs. And yet Hahnemann´s procedures for preparation of homeopathic medications are still rigorously adhered to by his many thousands of followers. Meanwhile, science has shown homeopathy to be nothing more than a quaint superstition.

"Superstition: Belief in the Age of Science" by Robert L. Park (2008)8

After a national review of medical practices stemming from the Flexner Report in 1910, homeopathy's flagship institution, the Samuel Hahnemann Hospital, stopped practicing homeopathy8.

3. Anti-Science, Anti-vaccination, Anti-Medicine: The Side-Effects of Homeopathy 15

#alternative_therapies #anti-science #botswana #MMR #UK #USA #vaccines

Homeopaths who are not medically qualified can miss fatal diagnoses, or actively disregard them, telling their patients grandly to stop using their inhalers, and to throw away their heart pills. There are plenty of examples, but I have too much style to document them here.

"Bad Science" by Ben Goldacre (2008)6

There is no legal regulation of homeopathic practitioners in the UK. This means that anyone can practise as a homeopath, even if they have no qualifications or experience. [...] Some homeopathic remedies may contain substances that are not safe, or that interfere with the action of other medicines. You should talk to your GP before stopping any treatment prescribed by a doctor or avoiding procedures such as vaccination in favour of homeopathy.


Homeopathy has continued to operate in not only a non-scientific manner, but often in an anti-scientific one - "it's routine marketing practice for homeopaths to denigrate mainstream medicine" notes one researcher6. In the West life is relatively peaceful, diseases are under control, and populations are mostly vaccinated. The worst that homepathy can do is occasionally manifest side-effects and impair real medicine, very occasionally cause death, and increase ignorance of real cause-and-effect in certain communities. But elsewhere, homeopathy has much worse effects.

4. What Would it Mean if Water Had Memory? And If Diluting Things Made Them Stronger?


The very statement that "water has memory" should be enough to put most educated people off of homeopathy straight away and it is one of the most widely ridiculed aspects of homeopathy. This is because water does not have memory, and it requires some pretty "special" thinking to even think that this is a possibility - let alone a possibility that happens to result in water's memories being able to cure Human diseases. How does the water know what to remember? Water molecules are so small and get mixed around so much, that a glass of water has collectively been through millions of toxins, poisons, sewers, countless other living bodies, and has been excreted in urine and faeces far more times than it has ever been near drugs that, when digested in the correct way, might help alleviate symptoms of a particular illness. The practitioner of homeopathy never mentions all of that! Even one of the great defenders, Benveniste, fails to explain this facet2. In addition, as a result of its simplicity, ubiquity and usefulness, the water molecule has been studied a lot by scientists. There is not a shred of evidence anywhere that water has memory. To put it in the same mild manner as Dr Goldacre, who has studied homeopathy, the very idea that water could have "memory" has "large conceptual holes"5.

The other absurdity, which clearly hasn't been thought out in much detail beyond "that's an interesting idea" is that if you dilute something, it makes it stronger. It can be easy to forget what a daft idea this is when reading homeopathic literature, and a good solution (no pun intended) is to instead talk about a well-known drug and see how the homeopathic theory sounds in that case, also remembering the idea that if a drug causes symptoms in a healthy person, it will have the opposite (curing) effect in an ill person:

If coffee keeps you awake, according to homeopathy dilute coffee will put you to sleep. The more dilute, the stronger the effect. If you keep diluting it until there isn´t a single molecule of coffee left, it will be even stronger. The water will somehow remember the coffee. If you drip that water onto a sugar pill and let the water evaporate, the water´s memory will somehow be transferred to the sugar pill, and that memory of coffee will somehow enable it to function as a sleeping pill.

Dr Harriet Hall (2014)4

5. What is the Evidence For and Against Homeopathy?

#science #UK

Repeated peer-reviewed scientific studies into homeopathy have found that it has no effect beyond the indirect placebo effect (which occurs when any treatment is given due to the client's positive perception). I emphasized peer-reviewed articles because there are many poor "scientific" studies that have concluded that homeopathic water is effective, but reviews of all tests that take into account the quality of the test have revealed that "there is an almost linear relationship between the methodological quality of a homeopathy trial and the result it gives. The worse the study - which is to say, the less it is a 'fair test' - the more likely it is to find that homeopathy is better than placebo" (Dr Goldacre 2008)5. "There are single studies that have found statistically significant differences between control groups and groups treated with [Homeopathy], but none of these have been replicated or they have been marred by methodological faults. An evaluation of five reviews of homeopathic studies has been done by Terence Hines who found that more than one hundred studies have failed to come to any definitive positive conclusions about homeopathic potions. There have been at least twelve scientific reviews of homeopathy published since the mid-1980s. Guess what? Homeopathic remedies are not more effective than placebos or no intervention1"2. A landmark meta-analysis of all studies into Homeopathy was published in the most prestigious medical journal, Lancet, in 2005, taking into account a huge number of trials3. This "was only the latest in a long string of meta-analyses to show that homeopathy performs no better than placebo"5.

To simply advise consumers that homeopathy is used to treat many health problems or that craniosacral therapy may prevent migraine attacks (Pinder et al. 2005) may look like a tempting shortcut to some, but it is hardly good enough evidence. Without evidence, we have no means of knowing whether such advice is helpful, irrelevant, or perhaps even detrimental. [...] An emphasis on prevention and self-care based on wishful thinking distracts from the few evidence-based preventative strategies currently available and is therefore counterproductive.

Dr Edzard Ernst (2007)

David Colquhoun, a professor of pharmacology at University College London, says that ignoring evidence (large-scale studies have shown homeopathy, for example, to be no more effective than a placebo) is ridiculous. "What can the idea of proper training in homeopathy actually mean?" he asks.

The Economist (2008)16

So what do homeopaths themselves make of the evidence? Obviously, because their product relies on psychological self-trickery, nearly all homeopathic commentary is based around testimonials ("It worked for me!", "These happy customers can't all be wrong!), and therefore places it amongst the crazy fads of history that are an embarrassment to humankind's heritage. Some other arguments are also used:

Homeopaths sometimes argue that because homeopathy is individualized, it can´t be tested in randomized controlled trials or judged by the same standards as conventional medicines. They are wrong: it can. Homeopaths could individualize their prescriptions as usual, the remedies could be randomized and coded by a second party, and they could be dispensed by a blinded third party who didn´t know whether what he was handing out was what the homeopath ordered or a substitute. Homeopaths involved in designing homeopathy studies have conspicuously chosen not to design them this way. [...]

Homeopaths love to cite statistics from nineteenth-century cholera and typhoid epidemics where patients treated with homeopathy were more likely to survive than patients treated with conventional medicine. Those historical successes are easily explained. [...] In 1800, conventional medicine was a disaster. Doctors weakened patients with bloodletting and purging, they poisoned them with mercury and other harmful substances, and they often killed more patients than they cured. [...] Doctors of the time were using remedies that often actively caused harm, but homeopathic remedies did nothing so of course the results were better. Homeopathy was just a way of avoiding iatrogenic harm.

Dr Harriet Hall (2014)4

It is highly recommended that you seek out the Skeptical Inquirer article by Dr Hall, and read the other sources I've been using as references on this page, for a wealth of information on some of the evidences for/against homeopathy.

The UK government executed one of the biggest investigations, involving proponents and opponents, and the resultant House of Commons report (2010 Feb 22) was completely clear that not only was the evidence completely against homeopathy14, but that so much research had already been done that there was no point in anyone doing any further studies - all questions have already been answered. Some bullet points from the document and Dr Ernst's reporting of it:

Some UK institutions had taken to supporting homeopathy and to studying its traditions. But the scientific reaction has been steadily increasing in outrage and effectiveness, and the UK's National Health Service reports on homeopathy thusly:

The National Institute of Health and Care Excellence (NICE) advises the NHS on proper use of treatments. NICE currently does not recommend that homeopathy should be used in the treatment of any health condition.

National Health Service online introduction to Homeopathy (accessed 2015 Sep 30).

"David Colquhoun, a pharmacology professor at University College London, has shamed some universities into ending alternative courses. The number of homeopathic hospitals in Britain is dwindling"10. There is a chance that with continued pressure, such rubbish can be kept far at bay from any institution, and its practitioners can be pressurized into ceasing to make the pseudoscientific medical and health claims that they are too often caught making.

6. So What is This 'Placebo Effect' Which Makes Homeopathy Seem Effective?


The following is an extract from The Placebo Effect and the Positive Power of the Mind on Health.

The placebo effect is a positive effect on an illness or medical condition, or on a health-related outcome, that results from suggestion and expectation17. This subtle psychological effect occurs whether or not the underlying treatment actually works and it is strong enough to continually distort medical studies into the effectiveness of health products and can make products seems effective when they are not - it can even do the same for surgical practices.18,19. Such unexpected effects have been studied in greater and greater detail by medical researchers, and it has emerged that placebo effects come in various forms20. The placebo effect is particularly significant in areas such as pain relief and stress, and is therefore best at overcoming aches and pains, headaches, stress-related conditions including recovery from stomach ulcers17 and skin rashes. Most complementary and alternative medicines (CAM) and alternative therapies work through indirect psychological effects, and by the turn of 20th century many New Age related remedies and practices were based on cures by suggestion21. The placebo effect is the reason why these remedies appear to work for so many people, when in reality they don't have any medical effect22,23,24,25,26,19,27,28 and its effects can often support erroneous ideas as to how disease works, and how healing works.

How does it work? (1) There is a link between mood and mental states of mind, and between mood and our immune system, meaning, that our overall impressions of a treatment can affect our outlook, which can boost our immune system29,30,31. (2) When it comes to pain, the prefrontal cortex of the brain can suppress pain messages from the insula32 and other places, meaning that if we prime ourselves to feel less pain (such as when expecting a pill to work) then it really does dull pain. Many experiments have confirmed the ability of people to mentally control pain. (3) Classical conditioning means that many elements of merely receiving a treatment cause our brain to release neurotransmitters and other learned responses in anticipation of feeling better, which improves how we feel18,27. (4) The Hawthorne Effect - people tend to live healthier and perform better simply because they are being studied23,27. (5) Receiving treatment can boost confidence and reduce stress, both of which can improve healing and feelings of wellbeing18,27,33.

"The Placebo Effect and the Positive Power of the Mind on Health" by Vexen Crabtree (2016)

7. Case Study: The USA 15


People... probably do not even notice the word "homeopathic" printed in small letters on the box. Many would have no idea what it means if they did. Most people believe any medicine sold in America must have been proven to be safe and effective. Unfortunately, that´s not the case. [...] Congress has seen fit to enact certain exemptions to... food and drug laws. In particular, Senator Royal Copeland of New York, who was a homeopathic physician before entering the Senate, was the chief sponsor of the 1938 Food, Drug and Cosmetics Act. It included a provision explicitly exempting all homeopathic medications listed in the Homeopathic Pharmacopoeia from FDA oversight. That exemption is still on the books today. Copeland's justification for the exemption was quite simple: there is no way to confirm that a homeopathic preparation is what it claims to be. The effect of the exemption was to give homeopathy an edge over all the other snake oil on the market.

"Superstition: Belief in the Age of Science" by Robert L. Park (2008)34

Current edition: 2015 Sep 30
Parent page: Human Health and Self Development

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References: (What's this?)

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Skeptical Inquirer. Magazine. Published by Committee for Skeptical Inquiry, NY, USA. Pro-science magazine published bimonthly.

The Economist. Published by The Economist Group, Ltd. A weekly newspaper in magazine format, famed for its accuracy, wide scope and intelligent content. See for some commentary on this source..

Carroll, Robert Todd. (1945-2016). Taught philosophy at Sacramento City College from 1977 until retirement in 2007. Created The Skeptic's Dictionary in 1994.
(2011) Unnatural Acts: Critical Thinking, Skepticism, and Science Exposed!. E-book. Amazon Kindle digital edition. Published by the James Randi Educational Foundation.

Davison & Neale
(1997) Abnormal Psychology. Hardback book. 7th edition. Published by John Wiley & Sons, Inc. Amazon link points to a newer edition than the one I've used here.

Gardner, Martin. Died 2010 May 22 aged 95.
(1957) Fads & Fallacies in the Name of Science. Paperback book. Originally published 1952 by G. P. Putnam's Sons as "In the Name of Science". Current version published by Dover Publications, Inc., New York, USA.

Goddard, Henry H. Dr
(1899) article "The Effects of Mind on Body as Evidenced by Faith Cures" published in The American Journal of Psychology (1899 Apr) vol. 10, No. 3, pp. 431-502. In James (1902) p112.

Goldacre, Ben. MD.
(2008) Bad Science. Published by Fourth Estate, an imprint of HarperCollins Publishers, London, UK.

Gross, Richard
(1996) Psychology: The Science of Mind and Behaviour. Paperback book. 3rd edition. Published by Hodder & Stoughton, London UK.

James, William. (1842-1910)
(1902) The Varieties of Religious Experience. Paperback book. Subtitled: "A Study in Human Nature". 5th (1971 fifth edition) edition. Originally published 1960. From the Gifford Lectures delivered at Edinburgh 1901-1902. Quotes also obtained from Amazon digital Kindle 2015 Xist Publishing edition. Book Review.

Lehrer, Jonah
(2009) The Decisive Moment: How the Brain Makes Up Its Mind. Hardback book. Published by Canongate Books, Edinburgh.

Myers, David
(1999) Social Psychology. Paperback book. 6th ('international') edition. Originally published 1983. Current version published by McGraw Hill.

National Health Service. (UK)

Novella, Steven Dr
(2010) "The Poor, Misunderstood Placebo". Published in Skeptical Inquirer (2010 Nov/Dec) p33-34. Novella is assistant professor of neurology at Yale School of Medicine and President of the New England Skeptical Society.

Park, Robert L.
(2008) Superstition: Belief in the Age of Science. E-book. Amazon Kindle digital edition. Published by Princeton University Press, New Jersey, USA.

Toates, Romero & Datta
(2004) From Cells to Consciousness. Paperback book. Published by The Open University, Milton Keynes, UK. A neurology textbook by Frederick Toates, Ignacio Romero and Saroj Datta.


  1. Ramey, David W. (2000) "The Scientific Evidence on Homeopathy". In Health Priorities, volume 12, number 1. In Carroll (2011) Appendix C Acupuncture, CAM (complementary and alternative medicine), and Faith p234-248.^^
  2. Carroll (2011) Appendix C Acupuncture, CAM (complementary and alternative medicine), and Faith p234-248.^^^
  3. Lancet (2005) "The end of homeopathy", 366:690.^^
  4. Skeptical Inquirer (2014 Sep/Oct), Harriet Hall, MD, article "An Introduction to Homeopathy". Available at^^^
  5. Goldacre (2008) chapter 4, "Homeopathy".^^^
  6. Goldacre (2008) chapter 5 "The Placebo Effect" digital location 1210-1253.^^
  7. Ben Goldacre (2008) (chapter 4) informs us that "In the 'What is homeopathy?' section on the Society of Homeopaths' website, the single largest organisation for homeopaths in the UK will tell you that '30C contains less than one part per million of the original substance.' 'Less than one part per million' is, I would say, something of an understatement"!^
  8. Park (2008) chapter 9 "The Barbary Duck, In which the body heals itself".^^^
  9. Goldacre (2008) chapter 4 "Homeopathy".^
  10. The Economist (2012 Apr 14) article "Medicine and its Rivals".^^
  11. The Economist (2009 Jan 24) article "Regulating alternative medicine" p35.^
  12. Goldacre (2008) chapter 5 "The Placebo Effect" digital location 1010.^
  13. Goldacre (2008) chapter 5 "The Placebo Effect" digital location 1060.^
  14. NHS web page "Homeopathy". Date last accessed 2017 Jan 30.^^^
  15. Added to this page on 2017 Jan 30.^^^
  16. The Economist (2008 Apr 19) article "Alternative medicine" p40-41.^
  17. NHS article The placebo effect and complementary and alternative medicine" (not dated, but "last reviewed" on 2016 Feb 03). Accessed 2016 Apr 16.^
  18. Goldacre (2008) chapter 5 "The Placebo Effect".^
  19. Toates, Romero & Datta (2004) p6-7,38-39.^
  20. Goldacre (2008) chapter 4 "Homeopathy" digital location 594.^
  21. Goddard (1899).^
  22. "Pseudoscience and Health: The World of Alternatives (to Truth)" by Vexen Crabtree (2014)^
  23. Goldacre (2008) chapter 8 "Pill Solves Complex Social Problem", digital location 1994-2009.^
  24. Carroll (2011) p154,251.^
  25. Gardner (1957) p187.^
  26. The Economist (2012 Apr 14) article "Medicine and its Rivals".^
  27. Novella (2010).^
  28. James (1902) p108 footnote.^
  29. Gross (1996) p145.^
  30. Davison & Neale (1997) p202.^
  31. Scientific American Mind (2009 Sep/Oct) article "Inflammation Brings on the Blues" p16.^
  32. Lehrer (2009) p143.^
  33. Myers (1999) p583.^
  34. Park (2008) chapter 9 "The Barbary Duck, In which the body heals itself" digital location 2121-2144.^

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