Whenever I give a public lecture about homeopathy, I explain what it is, briefly go in to its history, explain what its assumptions are, and what the evidence tells us about its efficacy and safety. When I am finished, there usually is a discussion with the audience. This is the part I like best; in fact, it is the main reason why I made the effort to do the lecture in the first place.

The questions vary, of course, but you can bet your last shirt that someone asks: “We know it works for animals; animals cannot experience a placebo-response, and therefore your claim that homeopathy relies on nothing but the placebo-effect must be wrong!” At this stage I often despair a little, I must admit. Not because the question is too daft, but because I did address it during my lecture. Thus I feel that I have failed to get the right message across – I despair with my obviously poor skills of giving an informative lecture!

Yet I need to answer the above question, of course. So I reiterate that the perceived effectiveness of homeopathy relies not just on the placebo-effect but also on phenomena such as regression towards the mean, natural history of the condition etc. I also usually mention that it is erroneous to assume that animals cannot benefit from placebo-effects; they can be conditioned, and pets can react to the expectations of their owners.

Finally, I need to mention the veterinary clinical evidence which – just like in the case of human patients – fails to show that homeopathic remedies are better than placebos for treating animals. Until recently, this was not an easy task because no systematic review of randomised placebo-controlled trials (RCTs) of veterinary homeopathy was available. Now, I am happy to announce, this situation has changed.

Using Cochrane methods, a brand-new review aimed to assess risk of bias and to quantify the effect size of homeopathic interventions compared with placebo for each eligible peer-reviewed trial. Judgement in 7 assessment domains enabled a trial’s risk of bias to be designated as low, unclear or high. A trial was judged to comprise reliable evidence, if its risk of bias was low or was unclear in specified domains. A trial was considered to be free of vested interest, if it was not funded by a homeopathic pharmacy.

The 18 RCTs found by the researchers were disparate in nature, representing 4 species and 11 different medical conditions. Reliable evidence, free from vested interest, was identified in only two trials:

  1. homeopathic Coli had a prophylactic effect on porcine diarrhoea (odds ratio 3.89, 95 per cent confidence interval [CI], 1.19 to 12.68, P=0.02);
  2. individualised homeopathic treatment did not have a more beneficial effect on bovine mastitis than placebo intervention (standardised mean difference -0.31, 95 per cent CI, -0.97 to 0.34, P=0.35).

The authors conclusions are clear: Mixed findings from the only two placebo-controlled RCTs that had suitably reliable evidence precluded generalisable conclusions about the efficacy of any particular homeopathic medicine or the impact of individualised homeopathic intervention on any given medical condition in animals.

My task when lecturing about homeopathy has thus become a great deal easier. But homeopathy-fans are not best pleased with this new article, I guess. They will try to claim that it was a biased piece of research conducted, most likely, by notorious anti-homeopaths who cannot be trusted. So who are the authors of this new publication?

They are RT Mathie from the British Homeopathic Association and J Clausen from one of Germany’s most pro-homeopathic institution, the ‘Karl und Veronica Carstens-Stiftung’.


29 Responses to Homeopathy works for animals – so it can’t be a placebo!

  • “We know it works for animals; animals cannot experience a placebo-response”

    I wonder why someone would think that way. I mean, there is still cartesian-enough people to think that animal don’t feel stress or comfort ? And this would not affect their capacity to heal or live ? It’s a 400 or 500 years ago point of view !
    Why are we following tons of ethic about animal experimentation ? Even cephalopode are included as sensible animal in Europe today.

    • What they also don’t seem to realise is that while animals can’t understand that they are being given something that is intended to make them better, for exactly the same reason they also can’t tell their owners that they feel better. Any assessment of the animal’s condition will be made by the owner, who knows they have been treated and hopes it has worked.

      • Yes indeed the major bias would be in the vet expectation. However, in positive “blinded” homeopathic studies, only the reviewer are blind to the poor design.

    • I do love the “Homeopathy works for animals – so it can’t be a placebo!” argument. Very few of its proponents have ever been able to respond sensibly to my observation that you can see placebo effect when all you’re doing is trying two different paints for a wall.

  • I don’t have access to the full text of the review, but I guess that the first of the two ‘good’ RCTs mentioned is the one I discuss in it’s a pretty bad study.
    I complained about it at Wageningen University, because the statistician involved acknowledged to me that they had known for quite some time that they made some errors. But they refused to publicly address those when requested by me (write a correction or something like that), just because homeopaths are using it in their propaganda as proof for homeopathy. The university declined in the end to look at my complaints, because they had not yet institutionalized the procedures for complaints from, which Dutch universities had agreed upon several years before.

    • Can you show another paper in a conventional study in animals ( conventional drugs ) in which they use a proper design and proper statistics ? So we can compare. Thanks .

      • Oh look, it’s the tu quoque fallacy. How about responding to the specific criticisms of the paper, George?

        • Not at all.

          Research typically follows a protocol which is common and accepted as a requirement for publication.

          This is the meaning of the objective markers in research and/ or in medicine.

          The study followed this protocol hence it complied with the requirements and it is considered reliable enough to be published whatever the results are.

          If the protocol and the typical process are wrong by design then there is no research that can be accepted as valid in the field.

          I m asking him to show an example of a study which follows the process and the design he considers “correct. If he cannot find one then he has to re examine his conclusions.

          • ..but I am not looking for one – I prefer to remain within my area of expertise.

          • George, it wouldn’t matter if there was not a single properly conducted study out there – the criticisms of this one would still stand. And you appear totally unable to address them.

  • My goldfish swims daily in a homeopathic environment. If it shows signs I interpret as getting sick, I change the water. So far, this has worked every time. What more proof of homeopathic efficacy could you possibly require?

  • @Edzard

    I did not initially mean your article and conclusions.

    I meant to respond on Pepijn van Erp comment on his blog. You see on his mind the review on homeopathy is positive and he was trying to ..debunk it. He essentially said that the design and the statistics were almost wrong.

    Does this make you think about your own conclusions regarding the paper?

    So i asked – and m still asking someone — to show how the application of the principles of a review or paper in this study departs from the typical study which is accepted for publication and there are no objections about its design and statistics; of course in the animals medication field.

    Or all medical research in this field is useless according to Pepijn van Erp criteria?

    Anyone? I m really curious.

  • There is a good paper which I can’t reference at the moment as I’m on holiday but I’m sure you can search easily in pubmed, on the caregiver placebo effect in animals. Effectively, both vets and owners perceived an improvement in dogs’ lameness when treated with placebo, when objective analysis with force plates showed there was no improvement. This is important because it shows we can all fool ourselves on the efficacy of a treatment, while the animal continues to suffer. Another paper on the placebo effect in animals looks at the placebo arm of three anticonvulsant drugs and found an improvement. Though the authors called this a placebo effect, this is likely regression to the mean given the nature of epilepsy.

  • I have just found what must be the most meaningless abstract ever [], and, of course, it is about homeopathy:
    Diluted above Avogadro’s number, homeopathic medicines allegedly do not contain any molecule of their starting-materials. As Western science is historically based on the notion of matter, alternative epistemological models are needed to account for the biological actions of homeopathic high dilutions. One such model is provided by biosemiotics, an interdisciplinary field devoted to the integration of biology and semiotics based on the fundamental belief that sign production and interpretation is one of the immanent and intrinsic features of life. Several experimental studies show that the information carried by high dilutions might be evidenced by means of measurable biological effects ranging from intranuclear epigenetic phenomena to inheritable adaptive processes, and regulatory physiological and behavioral phenomena. Therefore, when the action of homeopathic medicines is considered from the semiotic point of view, they become an endless source for studies aiming not only at therapeutic applications, but also to achieve a more refined understanding of living beings and their relationships with the environment.

    • Dr. Ernst –

      I saw that abstract as well and thought it laughably bad. At first I thought it must certainly be a parody or satire or other type of medical humour, but when there was no punch line, I realised that the ENTIRE ABSTRACT is the joke. Not surprisingly, this tripe is being held up by naturopaths and homeopaths as more “proof”. Proof of what…I’m not so sure.

    • Impressive. I wonder if they have already set up homoeopathic death registers that show that the people considered death by our vile classical medecine are actually alive when seen through this revolutionary view of reality.

  • Sir,
    Thanks for the article!
    When there are sufficient contradictions within the modern science itself yet Homeopathic remedies are marked placebo on the very plea of Avogadro’s number.We have shown in our following publication /blog how Avogadro’s number does not limit efficacy of homeopathic remedies ;
    1) “Avogadro’s number does not limit the efficacy of homeopathic remedies” published in Hpathy Feb2015 (
    2) “How and why Homeopathy is Scientific” (
    I would request all the viewers to spare some time for the said publication/blog and help us by posting their valuable suggestions therein.
    Biplab Chakraborty

    • With due respect Mr. Chakraborty, I will post a valuable suggestion.
      You will not like the following but as someone said in some humourous film scene: “You asked for it”.
      Before I offer my valuable suggestion I beg to first give my impressions of and reflections upon the references you provide. Or rather, only the first reference. The fact that it is past bedtime does not permit the added perusal of the second reference at present.
      The first reference, the “publication” as you call it and the site it is exhibited on, absolutely suffice to form a strong opinion and to construct a suggestion.

      To evaluate the quality of the repository on which the “publication” is presented, I had a look at some of the other material on the hpathy-dot-com site.
      Respectfully but honestly, I have to say I have never before seen an equally farcical collection of super-pseudo-sciency gibberish collected in one place. Believe me, I have taken part of many a collection of homeopathic writings but this one definitely takes home a prize for a catalog of gobbledygook.
      I was expecially awed at, and will use as an examle, the protracted “analysis” by a Mrs. Scharfstein who seems to be describing how she derived by observation of peculiar, almost psychotic-like ramblings, the conclusion that the patient was in need of a remedy made from the earthly remnants of an earthworm[sic] thinned to oblivion at 200C. The pompous use of the latin name for the particular, unfortunate invertebrate deserves honorable mention as an hilarious example of homeopathic grandiosity.
      I did not however particularly like the case history of the poor woman who had a recurring, difficult skin problem and a concurrent marijuana addiction. At length, the homeopath and apparently the patient also, fooled themselves royally into believing that her improvement over time was due to the magic of shaken-water-infused sugar pilules and not due to her pot-temperance, which very probably resulted in a generally improved lifestyle and her being taken properly care of by a genuine dermatologist. Just another example of the rampant post-hoc fallaciousness so ubiquitous in homeopathic self-endorsement.
      As to your opus, “Avogadro’s number does not limit the efficacy of homeopathic remedies”, that you want us to review and use as basis for valuable suggestions.
      I found this attempt at a learned article so abstract and confused that I was unable to follow any clear reasoning or rational deduction. I soon gave up concentrating on finding any comprehensible thread in the text so I speed-read to the the last couple of pages and the conclusion, or “inference” as you so scholarly call it.
      I am an avid amateur of chemistry and physics so I have a rather good understanding of the workings of molecules and matter in various states and of electromagnetic forces and other phenomena affecting their behaviour.
      The sheer absurdity of the whole paper convinced me that either the authors wrote this work under a marked influence of psychoactive substances or they have no bleeding idea or grasp of what they are talking about. If one or both of them were ever schooled in physics, the scholarship was definitely wasted as it seems to have left only a fair vocabulary of scientific words and terms but no understanding.
      The last paragraph of the article and the “inference”:

      Thus for the reasons cited above we suggest homeopathic dilution to be independent of Avogadro’s number in regards to presence of active medicinal molecules and instead dependent on electrical strain of water molecules induced by the medicinal molecules.
      Inference: Homeopathy has no relation to Avogadro’s number, in regards to molecules, but to the electrical strain in water molecules induced by the medicinal molecules through molecular orientations of water.

      As I said before… if this fantastic explanation of water “memory” happened to be true, how on earth would it survive the cataclysm of evaporation from the sugar pilules?
      Such demonstrations of homeopathic self gratification and delusions of grandeur, as this “publication” exemplifies and the Hogwart-esque collection of magic and mysticism on the hpathy-dot-com site make me extremely sad.
      Not because of the sadness induced by human beings managing to be so totally blind to their own folly but because of the realisation that P.T. Barnum was right.
      Now let us address the matter of a valuable suggestion.
      It is actually not intended for you Mr. Chakraborty. I do not think any words I write here will be able to release you from the confines of your cognitive dissonance and delusional mind. You will most likely take offence at my honesty. So be it.
      My suggestion is intended for anyone being remotely tempted to believe that an earthworm, macerated in a mortar and thinned to oblivion in liquid, will leave a hint (“memory” if you like) of something even minutely capable of affecting the physical or mental condition of a human being. Especially after being serially thinned to the super-ultra-way-above-Avogadro-astronomical order of one in ten to the power of 400. Even if the vial was shaken vigorously at every one of the 200 dilution-events the possibility of such haphazard manipulation inducing something necessarily specific should be astronomically remote. If by power of some hitherto undetectable phenomenon, the homeopaths were right, and the water molecules arranged themselves to retain even a hint of memory of the earthworms innards – or were somehow induced with a specific electromagnetic potential from the invertebrate, as seems to be the gist of the said “publication” y, falsely attributing the late Mr. Benveniste with having demonstrated something to that effect, then how do Mr’s Chakraborty and Amin explain how this structural or electromagnetic or whatever… memory is retained after said H2O-molecules leave the sugar pilules one by one in the demonstrably chaotic event called ‘evaporation’???
      I digress. The matter of a (hopefully) valuable suggestion awaits.
      My suggestion is directed as I said, not to the resident or visiting homeopaths. They are generally uneducable.
      No, my suggestion is to the paying (with their patience 😉 ) audience who come here to Professor Ernst’s repository of reason and rationality, for enlightenment and information as to the nature and utility of homeopathy.
      My humble suggestion is as follows:
      Whenever you partake of a description of how common homeopathic remedies are prepared, and start having doubts about the arithmetic reality involved in the process in relation to the resulting remedies’ purported powers. Then try doing a simple test of reality. Try adding together two and two using your fingers. If the result is four, then go and make yourself useful in something rational and reality based and be assured that reality is the one we can see and detect and describe.
      If the result is in any way unequal to four, then go and study homeopathy because your reality is alternate.
      If you do follow the second path instead of seeking expert help, then be prepared to receive the occasional derisive and subjectively hurtful late night piece of satirical critique from a tired, middle-aged surgeon who has had enough of the stupidity of make-believe medicine and does not think the discipline and practice of homeopathy deserves any more of his respect. But be assured, that this surgeon is despite this, in his heart truly respectful for the individual fellow human beings notwithstanding the absurdity of their beliefs or the blindness of their faith.
      PS. I suspect it will be appropriate to declare here and now, that this entire comment was written in a state of absolute sobriety but under the influence of mild sleep-deprivation 🙂

      • Respected Sir,
        Thanks for the comment. While appreciating your valuable comment we earnestly request you kindly to provide scientific explanations to the contradictions shown by us regarding Generation, Conduction and retention of electrical energy by distilled water as detailed below.
        A) Generation :How distilled water generates emf with different metals/non-metal electrodes without chemical reactions or having concentration difference of electrode /electrolyte as shown in table below
        Sl No. Electrode pairs Observed emf (in mV) In Distilled water

        1 Gr – Zn 1150
        2 Gr – Pb 778
        3 Gr – Cu 240

        Ref: “Untold Facts of Science –The Science Behind Homeopathy” (
        Ref:“ Generation of Electrode Potential of an Electrode” (

        B) Conduction: Here, please find this simple experiment with four graphite electrodes (GrA, GrB, GrC&Gr D) placed in a glass bowl containing 30 ml of distilled water at a distance of about 3.5 cm as shown in fig 3. The graphite electrodes GrC & GrD are placed just at the opposite side of GrA & GrB respectively. Now an LED is connected to GrC & GrD while a 9 volt battery is connected to GrA & GrB with positive end of the battery connected to GrA and negative end to GrB(connections shown in Figure3) (As the related figure could not be posted Please see Fig 3 of “How and why Homeopathy is Scientific” (
        Our observations: The emf shown at the GrC- Gr D pair is about 1.46 volts. The LED glows when its negative lead is connected to the Graphite GrD and positive lead to GrC
        Now, it is not clear how Direct Current is conducted from GrA (Graphite) & GrB(Graphite) to the neutral electrodes GrC & Gr D i.e. why the ions approach to neutral electrodes for generating emf of 1.46 volts at GrC –GrD and lighting the LED therein, as the existing theories only allow approach of any ions to its opposite electrodes while conduction of electrical energy i.e. cations (positive ion) to cathode(negative electrode) and anions (negative ions) to anode(positive electrode) .
        If there exist any such theory that permits approach of ions even at neutral electrodes while conduction of electrical energy, may please be intimated.

        c) Retention: Here, please find another simple experiment wherein a pair of electrodes Cu & Zn are placed in a beaker containing distilled water and its emf recorded to be 914mV (Fig. 7). (As the related figure could not be posted Please see Fig 7 of “How and why Homeopathy is Scientific” (
        After recording of initial emf , direct current from a source of 9 volt battery is allowed to pass through it, such that the positive terminal of the external source(i.e 9 volt battery) is attached to the positive electrode (i.e: Cu) & negative terminal to the negative electrode (i.e: Zn) . The direct current from the external source is allowed to pass for 60 seconds and thereafter disconnected. The Final reading of Cu & Zn pair is recorded to be 1250 mV after 15 seconds of disconnecting the circuit i.e. there is clear increase in emf of Cu & Zn pair (1250-914=336mV)
        Now, How Direct current is retained even in distilled water i.e. distilled water is able to hold electrical charge similar to that of a rechargeable battery / accumulators may please be explained in the light of existing theories of Science .
        Ref: “Water the Magic Liquid: Retaining Electrical Energy” (

        Further , we shall provide you some of our more experimental results for your chemistry based explanations later on.
        Biplab Chakraborty & Ruhul Amin

        • Biplab Chakraborty, You have presented a really good example of the incessant quackery that has underpinned the vending of homeopathy since its inception more than 200 years ago. However, the number of diseases that homeopathy can actually cure has always been zero. The only things that watching the LEDs in your experiment seems to have circumvented is your rational thinking and medical ethics.

          • Respected Sir (Pete Attkins)
            I shall only request you to provide scientific explanations for the above mentioned experimental results in the light of existing theories of science i.e. in respect of following FUNDAMENTAL CONTRADICTIONS IN SCIENCE
            i) how electrodes generates emf when placed in distilled water without any chemical reaction.
            ii) how ions are conducted to even neutral electrodes
            iii) how water retains electrical charge.
            Thanks .
            Biplab Chakraborty

          • Biplab Chakraborty, As you well know, this has already been answered under you duplicate post on another article:

            Everyone who has a basic understanding of physics and chemistry will see the absurdity of your comments — all of which have nothing whatsoever to do with the well-established fact that homeopathy doesn’t cure any known disease in humans or in other animals.

            PS: I very much hope that you do not store your distilled water in glass or metal containers.

        • I’ve now read through several of the reports on and although I’m not a trained physical chemist I find them rather odd. There’s a fascination with including LEDs as an indication of current passing, rather than measuring the current and the precision and accuracy of the measurements doesn’t seem appropriate for the style of experiment (and frankly I wonder if the experimenters are aware of the distinction between “precision” and “accuracy”).

          I’ve tried to find some of the papers the site says Chakraborty & Amin have published “He along with Dr. Md.Ruhul Amin published papers on Homeopathic Dilution & its scientific Basis. These papers clearly reflect the contradiction within the modern science itself.” but although I can find nine publications by Chakrobarty & Amin, they’re not our Chakraborty and Amin and none are on homeopathy. Anyone know where they can be found?

          But all this is irrelevant. We don’t need a mechanism by which homeopathy COULD work – because it doesn’t. I didn’t work 200 years ago and the discovery of sub-atomic particles didn’t make it work. The discovery that mass warps space didn’t. The discovery of the Higgs boson left homeopathy as functionless as before.

          I’ve said elsewhere (not sure if it was in this discussion) that I am TOTALLY willing to believe that people who attend will report that they feel better after the treatment. But I DON’T accept that it was because of the . I’ve presented several mechanisms whereby inactive treatments will APPEAR to have an effect if you don’t do your measurements properly and the reported effects of homeopathy are no better than my hypothetical functionless remedy.

          I therefore see no reason to believe that homeopathic remedies have any effect – and until we see better evidence, looking for a mechanism seems futile.

          • Aargh. The parser has deleted bits I put in angle brackets. I meant to write:

            “I’ve said elsewhere (not sure if it was in this discussion) that I am TOTALLY willing to believe that people who attend {insert style of therapy} will report that they feel better after the treatment. But I DON’T accept that it was because of the {style of therapy}.”

  • Dear Professor,

    thanks for the interesting review. However for me it seems it is not telling anything about whether animals are subject of the pacebo effect or not. The review “only” shows that veterinary honeopathy is not superior OVER the placebo arm. One should tell anything about placebo only if there is a 3rd arm – non treated?

    Am I misunderstanding something?


  • OK, sure, there is no disagreement between us in that. So based on this review we can say that as the results of the (placebo) control and the verum arms are the same, it is not worth to go into the debate wether animals are subject of placebo or not.


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