Placebos as Medicine: The Ethics of Homeopathy

sugar + lactoseIs it ever ethical to provide a placebo treatment? What about when that placebo is homeopathy? Last month at Science-Based Medicine I blogged about the frequency of placebo prescribing by physicians. I admitted my personal discomfort, stating I’d refuse to dispense any prescription that would require me to deceive the patient. The discussion continued in the comments, where opinions seemed to range from (I’m paraphrasing) “autonomy, shmatonomy, placebos works” to the more critical who likened placebo use to “treating adults like children.” My SBM co-blogger Harriet Hall noted, “We should have rules but we should be willing to break them when it would be kinder to the patient, and would do no harm.” And on reflection, Harriet’s perspective was one that I could see myself accepting should I be in a situation like the one she described. It’s far easier to be dogmatic when you don’t have a patient standing in front of you. But the comments led me to consider possible situations where a placebo might actually be the most desirable treatment option. If I find some, should I be as dogmatic about homeopathy as I am about other placebos?

Nicely, Kevin Smith, writing in the journal Bioethics, examines the ethics of placebos, based on an analysis of homeopathy. Homeopathy is the ultimate placebo in routine use — most remedies contain only sugar and water, lacking a single molecule of any potentially medicinal ingredient. Smith’s paper, Against Homeopathy — A Utilitarian Perspective, is sadly behind a paywall. So I’ll try to summarize his analysis, and add my perspective as a health care worker who regularly encounters homeopathy.

The first third of the paper is a concise summary of the scientific absurdity of homeopathy. Hahnemann’s “Law of Similars”, based on a single observation of the effects of quinine on malaria, is the basis for the non-scientific process of “provings” to match symptoms to substances. The results of provings are compiled in the Homeopathic Materia Medica, which homeopaths select their remedies from. (So now we have remedies based on products including “sleep”, Stonehenge, shipwrecks, ascending colons, light bulbs, and vacuum cleaner dirt.) Smith summarizes this law as:

More fundamentally, there is simply no plausible or rational basis for supposing that substances that produce particular symptoms can cure the same symptoms. The assumption that ‘like cures like’ places the onus on proponents of homeopathy to elucidate the special logic involved: to the knowledge of the present author, a satisfactory account of this logic has not been made.

Hahnemann’s second law, the “Law of Infinitesimals” is as absurd as the law of similars. That a product can gain potency and effect with dilution, and that effect persists (and even grows stronger) even after being diluted completely away defies physical laws. Smith points out the contradiction between the idea that water is touted to have a memory of the “proved” substance, yet has forgotten everything else that has every been dissolved in it:

The fact that physiological chaos does not ensure whenever we drink a glass of water provides a simple but powerful refutation of the ‘memory’ concept in homeopathy.

Smith then covers the research on homeopathy. Given its premise is implausible (or impossible), it is not surprising that the highest quality clinical trials have demonstrated no efficacy beyond placebo effects. Yet positive trials are to be expected from statistical effects alone. And when combined with bad design, weak blinding and other potential biases, it should not be surprising that a supportive clinical trials appear in the literature — and some even show up in Cochrane reviews. His conclusion is very much along the lines of the position taken by SBMers:

From Hume onward, it has been accepted that extraordinary claims require extraordinary evidence. Considering the extent to which the fundamental tenets of homeopath run counter to established rules of science and reason, empirical evidence in support of homeopathy would have to be particularly robust, in view of the fact that acceptance of homeopathy would entail a major epistemic scientific revolution.

So it’s implausible, the remedies contain no medicinal ingredients, and, not surprisingly, it works no better than a placebo. Yet it is popular, even among some physicians and scientists. But is it ethical? And here’s where we get to the meat of the ethical analysis.


Placebos, as commenters to my past post noted, do have one merit. If the alternative to antibiotics for a cold is homeopathy for a cold, then homeopathy is probably a better therapeutic choice, because “no treatment” is the preferred treatment. There are many medical conditions for which we have few effective medical therapies, and in some cases the impetus to prescribe a placebo may be simply to obtain the psychological (placebo) effects associated with their use. And given the habit (as I described last month) for some physicians to select impure placebos (those containing subtherapeutic or non-toxic ingredients), then isn’t a pure placebo like homeopathy sometimes preferable? Here’s where Smith gives homeopathy credit:

In cases where ineffective medication is considered to be in the best interests of the patient, which form of such medicine should be prescribed?

The answer to this question seems clear: the ineffective medicine that is the least invasive and least expensive should be used. On these criteria, homeopathy scores highly.

So in situations where a placebo is felt to be in the patient’s best interest, homeopathy might be felt to be favorable, particularly if an “impure” placebo has a greater potential for unwanted effects. But Smith makes a small error here: Homeopathy isn’t always the least expensive option – a point I’ll return to.


Holistic is a popular term among alternative medicine proponents and is usually used to deride science-based medicine, with the fallacious claim that various alternative treatments treat the “whole patient” while medicine does not. And as has been described elsewhere on this blog, the extended consultation offered by alternative medicine providers is probably the source of most if not all of the benefits of treatments. However the non-specific benefits of talk therapy, dialogue, empathy and reassurance are not limited to homeopathy, and can be incorporated into science-based practices. And importantly, since homeopathic “remedies” can be purchased in pharmacies and other stores without consultation, the “holistic” approach, and its benefits, are by no means certain when consultation is omitted. For these reasons, Smith rejects holism as providing any unique support for homeopathy.

Placebo effects

In the research setting, placebo effects are any measured response in patients that receive the inert (placebo) treatment. But as has been noted on this blog, there are actually multiple elements and observations that sum into what’s described as “placebo effects.” Some of what can contribute to the apparent efficacy of a placebo may not be due to patient-reported outcomes: Researcher bias, poor blinding, and weak overall study design and conduct can all add to the measurement of, and subsequent conclusion that a placebo has effects. Even a disease’s natural history, or regression to the mean can lead one to conclude a correctly-timed placebo treatment is effective.

Smith does not dive deeply into placebo effects, but makes two arguments against homeopathy’s value as a placebo. First, he notes that placebo effects are generally restricted to subjective symptoms like pain and fatigue, with no evidence supporting any meaningful disease-modifying effects. This limits the usefulness of homeopathy to those conditions for which there is some evidence to show that there may be placebo effects. Smith then raises the ethical appropriateness of a key component of successful placebo use: in order for placebos to work, patients must believe something that is untrue. From a utilitarian perspective, Smith notes that lying may be acceptable when it (on balance) is an overall positive — that is, it generates a positive utility. However, patient autonomy must also be considered — the right for patients to make an informed decision about their treatments. Smith suggests that if you personally rank autonomy above the potential placebo benefits, then the use of homeopathy is untenable from an ethical perspective.

But are homeopaths deliberately deceiving their clients? Smith argues (and I agree) that most homeopaths genuinely believe “remedies” to be effective — so they are not acting in bad faith when they advocate their use. However, the fact remains that patients that are told that homeopathy is effective are being given information that is contrary to the scientific evidence. Consequently Smith describes their actions as “ethically unacceptable” regardless of their sincere (but wrong) beliefs.

But what about placebo use by health professionals? While routine use of placebos wouldn’t be considered ethically acceptable, Smith notes that reinforcing the efficacy of a conventional medication, in a way that could enhance potential placebo effects, is acceptable. This is a routine part of the pharmacist’s dialogue with patients – understanding and addressing concerns, summarizing therapeutic effects, and managing overall treatment expectations. It can be done in a non-deceptive way that should maximize the non-specific effects. But what about pure placebos? Smith gives the example of battlefield use of saline injections for pain as a circumstance where pure placebo use would be ethically acceptable. So in situations where no other options exist, perhaps. But as a matter of course, providing pure placebos would not be considered ethically appropriate.


What if patients elect to choose homeopathy, despite counsel that the product is inert? I’ve encountered this situation in the pharmacy: when asked for advice, I inform the patient that the product has no active ingredients and has no medicinal effects. They’re usually grateful for that, but sometimes my advice will be challenged or ignored, and they’ll purchase it anyway. In situations where it’s clear that the patient may be avoiding appropriate consultation or treatment, I may press my argument further. But once I’ve described the scientific evidence, and given my advice, I’m comfortable letting the patient make their own purchasing decision. And that’s consistent with Smith’s analysis:

If utility is generally maximized by allowing patient autonomy, then patients should be free to choose homeopathy. Secondly, exercise of autonomy provides psychological benefits for the agent: it is well accepted that denial of free choice, or coercion, results in reduced happiness in the subjects concerned.

Smith describes the challenge of drawing lines between paternalism and autonomy, concluding that restriction of autonomy is probably reasonable when the risk of self-harm is greater — which is consistent with the case for restricting drugs to “prescription-only” status. While risks of contamination and unwanted medicinal effects do exist, the more common and real risk is probably the avoidance of proper medical treatment — which is one of the major disutilities of homeopathy.

Failing to Seek Medical Care

While some might be willing to accept the use of homeopathy in cases where placebo effects are possible and probably adequate, most draw the line when homeopathy is positioned as a substitute for effective medical treatment. Yet that’s the case when homeopathy is promoted as malaria prophylaxis, a substitute for vaccination, or even as a treatment for HIV or tuberculosis. Probably the best approach to mitigating this risk, while promoting individual patient autonomy, is to ensure that adequate information is provided to patients so that they are well informed of the lack of medicinal ingredients and the demonstrated lack of efficacy, beyond placebo, for any condition. Smith questions the ability of CAM practitioners to provide reliable advice on efficacy, and describes the promotion of a therapeutic doctrine, rather than reliable advice, as “ethically unacceptable.” He further characterizes any harms resulting in those unable to give fully informed consent (e.g., children or non-competent adults) as “ethically indefensible.”

Waste of Resources

If you’ve never bought it before, homeopathy is not cheap: its prices are comparable to conventional products with active ingredients. Given the lack of efficacy, every dollar spent on homeopathy is a waste of resources, in that it could otherwise be put to more effective use — for plausible treatments, or anything else, for that matter. So from a utilitarian perspective, Smith argues that this expenditure is unethical. Smith notes that homeopathy may not just act as a substitute for other care due to its lack of effect: When the homeopathy fails to work, conventional care may subsequently be sought.

Smith makes the same ethical evaluation of research into homeopathy, where because of a lack of “logico-scientific validity”, human trials of homeopathy are ethically contentious and an inappropriate use of resources.

Credibility Issues

One of the issues that concerns me as a pharmacist is the veneer of credibility that homeopathy gains when it’s packaged and positioned alongside conventional medicine in pharmacies. I suspect that most consumers expect the products on pharmacy shelves to contain medicinal ingredients, and to have some sort of evidence to support their sale. If I substituted placebos for prescription drugs, I’d quickly lose my license to practice. And if I sold boxes of toothpaste or tissue that were empty inside, I’d probably be out of business pretty quickly. So I’m dismayed when I see pharmacies selling cough syrups without active ingredients, sending an unwarranted message of homeopathy’s effectiveness.

Another credibility issue arises from an educational perspective, when homeopathy is “integrated” into science and and medical education as well, increasing the perception that homeopathy has medical credibility. Smith sums it up:

“…inappropriate ‘approval’ for homeopathy serves as a disutility, as it will tend to magnify several negative outcomes, namely resource wastage, risk of patients failing to seek effective healthcare, and reduced patient autonomy through the promulgation of erroneous medical knowledge”

Smith goes on to note a number of other concerns documented repeatedly at SBM, including a weakening of a societal commitment to scientifically-established treatments, as well as the confusion of ineffective treatments such as homeopathy with treatments that he describes as genuinely complementary, such as mediation, relaxation, music and exercise — something that has been described here as the CAM Trojan horse.


So where does that leave us? Unfortunately we cannot simply sum up the arguments in a formula to give us the ethical answer. It seems clear that the ethical downsides to homeopathy outweigh its benefits under most circumstance I can envision. Smith uses the example of an ineffective defibrillator to point out that the use of such a device device in the context of medical care would be “morally unjustifiable.” He notes,

Because it is inherently ineffective, homeopathy cannot be ethically neutral. It follows that the purchase, deployment or promotion of homeopathy is morally unacceptable.

Perhaps there may yet emerge a framework where placebos can be ethically (and judiciously) justified. Homeopathy isn’t it. So what should health professionals do? For one, we should stop promoting homeopathy, and the sale of homeopathic remedies. We should advocate against the allocation of limited health resources to researching, facilitating or providing homeopathy. We should avoid giving homeopathy undeserved credibility by selling it alongside actual medicine, or allowing it to be sold without clear labelling that describes its lack of ingredients and effectiveness. And when we’re asked, we have an ethical responsibility to explain why we believe homeopathy is no ‘alternative” at all.

ResearchBlogging.orgSmith K (2011). AGAINST HOMEOPATHY – A UTILITARIAN PERSPECTIVE. Bioethics PMID: 21320146

17 thoughts on “Placebos as Medicine: The Ethics of Homeopathy

  1. This is really excellent. As someone who teaches ethics (including both business ethics and bioethics) at the university level, I’d say you’ve explained Smith exceptionally well.

    Smith’s argument is absolutely right, and your exposition of his position is bang-on.


  2. So how do you justify writing ‘scrips for synthetic meds that have trial after trial produce results less than placebos, yet when they do finally find one shows efficacy, they use that one to get the drug authorized ?

    this is a big deal in third world drug trials. Is this just greed, or something even more sinister?

    let alone the standard stuff you are talking of here.
    Med-Tech : Drugs RSS
    Placebos Are Getting More Effective. Drugmakers Are Desperate to Know Why.

  3. BestPanacea…

    It would represent considerable progress if fans of homeopathy would admit, as you seem to, that the placebo effect is really what’s at stake here.

    But if the potency of placebos is supposed to underpin support for homeopathy, we should keep in mind that the power of placebos will likewise provide support for voodoo and lucky rabbits feet.


      • Religion is quite possibly the placebo of the masses, but what has your statement got to do with the price of fish?

        Anyway, this morning we conclusively established that the only placebo that works is a nice wee cup of tea and a biscuit.

  4. Awesome article.. I’m working for a mid-sized pharmacy chain whose big push is adding homeopathic products. Your article has been helpful in giving some of the ‘business’ guys an idea of why most of their pharmacists aren’t supporting their new product line. Your clear explanations have already converted a few — keep up the good work!

  5. Liked the article. Having locumed opposite a surgery where a GP Rx’d these for almost all conditions. The multiple i was working for where quite comfortable with it as it continued to boost Rx vols so no issues were directed to patients.

  6. Great post. I totally agree and still question why intelligent people lose all rationale when it comes to Homeopathic Medicine. I am so tired of hearing about how ‘Pharma’ is bad and CAM providers are more interested in healing the patient? “There is no standardized, national system for credentialing CAM practitioners, as a whole, to provide services.” – taken from

    I wonder if anyone at has read your post. Especially as “Potential Roles of the Placebo Effect in Health Care” is posted on their home page.

  7. And now they find that the more expensive a placebo is, the more effective it is.


    Maybe lumping homeopathy and placebos together is not good science.
    Again, i have not seen you address the fact that “standard” medical derived drugs are losing effectiveness in trials. most are well BELOW placebo effects, and it is said they have to re-run these trials into multiple runs, until they can beat the placebo effect.

    How is that any different than the effects of homeopathy?

  8. Morganism; the placebo effect may indeed by affected by price, just as it is by presentation, even to the colour of the dummy pills or whatever.

    Lumping homeopathy and placebos together is perfectly good science, because homeopathy is nothing but placebo.

    As for standard drugs having below-placebo performance, I’ll have to slap a dual [Citation needed]/FPI order on that one. The last time I saw something with slightly sub-placebo effect, it was the sham acupuncture in the does-acupuncture-improve-effects-of-IVF study (results=No more than a nice cup of tea and a biscuit) that came out over this summer.

    BTW, good post Scott. Well and concisely stated.

  9. What about the prescription of antiobiotics for viral infections in order to placate the patient even though (we know) they will not treat the infection. Could we construe this as placebo?

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