The Cognitive Dissonance of Homeopathy

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A pharmacist’s education is rooted in the study of the natural sciences. It’s training that lends itself to sorting out novel, science-based therapies from implausible pseudoscience.  To the the chagrin of the science-based pharmacist, homeopathic products are widely available at pharmacies in Canada and around the world. Many pharmacists endorse homeopathy and see it as complementary to conventional (real) medicines.  Others argue that they’re simply responding to consumer demand.  Is homeopathy based on sound science, and should homeopathic products be sold in pharmacies?


Homeopathy was invented in the early 1800s by a German physician, Samuel Hahnemann. At that time, illness was believed to be the result of imbalances in the four bodily “humors”, namely blood, phlegm, black bile and yellow bile. Typical medical treatments were crude and dangerous, and included bloodletting, blistering, laxatives and emetics, intended to bring balance to the humors. Hahnemann invented an alternative treatment system that he believed was less toxic and more effective at balancing the humors.

There are three key principles for homeopathy, and they’re fundamentally different from our current, science-based understanding of drugs and diseases.

Like Cures Like: The “Law” of Similars

With little understanding of the root cause of disease, Hahnemann concerned himself with treating symptoms. He identified products that, when consumed, he believed produced similar symptoms in well people. This, he felt, could be used to restore the humors in the ill, and he called it a “proving”.  Don’t confuse “provings” with “proven”: There is no objective or unbiased evaluation of a proving. And whether the product actually had an effect on the actual disease was of secondary concern.

Individualized Therapies

Hahnemann felt that every therapy needed to be customized based on a patient’s symptoms and characteristics, including the emotions and moods of a patient.

Consider the homeopathic remedy “Natrum Muriaticum” aka “Natrum Mur“. Patients that require this are described as:

“Usually reserved or introvert, less communicative about personal matters. Less social. Sadness which is not easily expressed. Emotional and sensitive. Weeping alone, does not desire sympathy. Sincere sympathy is appreciated, though. Does not like to be pitied. Grief, unexpressed. Sympathetic. Revengeful thoughts when hurt.” Source

Natrum Muriaticum is sodium chloride: table salt. The list of who can apparently benefit from table salt goes on and on.   It reads like a parody until you realize the authors are serious.

Less is More: The Law of Infintesimals

The smaller the dose, the more potent the product, according to Hahnemann.  How small of a dose? Almost beyond comprehension. Through successive dilutions, (and shaking of the vials) unbelievably dilute solutions are obtained – so dilute that most mixtures contain no active ingredient. The 30C “potency” is common – it’s a ratio of 10-60.  You would have to give two billion doses per second to six billion people for 4 billion years to deliver a single molecule of the original material to any patient, notes Wikipedia. Simply put, patients are getting water – that’s it. Homeopaths struggled for an explanation until they could invent one – apparently the molecule leaves some sort of an imprint on the water – a theory which has been definitively disproved. The water is then dried on sugar tablets, or sometimes sold in liquid formats. Regardless of form, the final product for sale in the pharmacy is unlikely to contain a single molecule of anything that could have any effect in the body.

Homeopathy versus Real Drugs: How do they compare?

Logical gaps are the hallmark of homeopathy.  Let’s compare homeopathic products to real drugs on the basis of accepted pharmacologic principles. The product monograph is the official, approved information compiled for real drugs, and I’ll use this format to look at each aspect of therapy.


Real Drugs are used to treat, prevent, or diagnose a disease. Before a drug can be sold, its use must be approved by a regulator (such as Health Canada or the FDA). The standard for approval is very high. It can take many years and millions of dollars to bring a new drug to market. When a drug is approved, it is indicated (approved) to be used only in certain ways – typically only for a specific disease and even specific types of patients.  Our understanding of many diseases has progressed so significantly that we can predict which patients will respond to some drugs based on testing specific genetic markers.

Approvals for drugs can change over time. If evidence emerges that drugs show no benefit in some groups, or that the risks outweigh the potential benefits, (e.g., cough and cold products in children) approvals can be withdrawn.

Homeopathy ignores the biologic basis of disease, and focuses exclusively on symptoms. Your nausea may be from chemotherapy or motion sickness, but if your symptoms are the same, the homeopathic treatment is identical. There is no regulatory oversight to measure the effectiveness of homeopathic products.

Clinical Information

Real drugs are evaluated in clinical trials that are usually randomized, double-blind, and placebo-controlled.  This process minimizes bias and is the best method available to objectively evaluate the effectiveness of a drug. In order for a drug to be approved for sale, some sort of persuasive evidence is necessary to demonstrate the drug can be used safely and effectively. Wishful thinking and anecdotes aren’t adequate to justify approval.

How does homeopathy compare? Many clinical trials have been conducted on homeopathy. Most are small and poorly done.  Overall, the evidence is consistent with the conclusion that the effects are nothing more than a placebo. If homeopathy was held to the scientific rigor required for real drugs, there would be no homeopathic products permitted for sale.


Real drugs are carefully evaluated for how they are absorbed, distributed, metabolized, and eliminated – that is – how much gets into the body, where the drug goes, and how the body eliminates it.


How well a drug is absorbed determines how it’s given. Some drugs are not destroyed by stomach acids, and can be given as a tablet or capsule. Liquids forms may be necessary when the dosage needs to be adjustable – say in the case of antibiotics for children. Others must be given by another route – say through the skin, or by injection.

Homeopathic remedies are typically given orally.  Homeopaths believe the dilution process creates some sort of a lasting imprint on water molecules, and this magical impression can withstand drying on sugar tablets, digestion by stomach acids, and presumably absorption into the body.


Once absorbed, real drugs dissolve in body fluids, such as blood. Once it enters the body, enough needs to be present for it to exert its desired effect (e.g., lower blood pressure).  How and where the drug goes in the body can be measured.

Homeopathy runs into trouble here. The more dilute the product, the stronger the effect, says the theory. So if less gets into the body, is there a stronger effect? Hmm.  Where homeopathic products are believed to work in the body is pure speculation – there is nothing that can be objectively measured.


Many drugs cannot be removed from the body easily, so the liver transforms them into something that can be more easily expelled.

Hahnemann’s theory doesn’t hold up here, either. It’s not clear how the water molecule imprints made it this far into the body, but then somehow stop working. There’s no correlation with how the original (non-dilute) source product, if administered, would be metabolized.


Most real drugs are filtered out by the kidney and discharged in the urine. How quickly a drug is flushed out from the body helps determine how often it needs to be taken.  This is why some drugs are dosed hourly, some daily, and some weekly – careful evaluation give us the information to make a science-based decision.

Here is where homeopathy really falls apart. If homeopathy is more potent the more dilute it is, how does the effect wear off? Does the concentration increase in the body? Well, it must wear off, as they all apparently last about eight hours, regardless of the product, or the potency:  They’re all usually administered three times per day. This is curious given the tremendous variety of homeopathic products.

Contraindications, Warnings and Precautions

Real drugs have an effect in the body. Sometimes, specific groups of patients should not take a drug, it may be because of patient factors, or because of other diseases that they may have.

Contraindications to homeopathic products? None. How could there be? There is no active ingredient and no demonstrable positive effects.

Drug Interactions

Real drugs may not mix well with other drugs. These interactions are predictable, manageable, and sometimes even desirable.

Homeopathy can’t interact with any drug, or even any other homeopathic product, as there’s no active ingredient. Placebo+placebo=placebo. Placebo+real drug=real drug.

Adverse Effects

Real drugs can and do have side effects. They may be unpredictable and rare, but are more commonly an extension of their intended effect. (e.g., Low blood pressure can make one lightheaded.)  Post-marketing monitoring by regulators and manufacturers helps identify these patterns in adverse effects. Safety profiles of drugs typically continue to evolve over time, as more information is collected on their use.

As they have no positive effects, homeopathic products can have no adverse effects.  Aside from the consequences of delaying real treatment, the only other certain effect is a lighter wallet.


“Did you hear about the patient that was taking homeopathy? He forgot to take a dose and died of an overdose.” – Pharmacist humour

Real drugs can have toxic effects if taken in excess. Overdoses are managed based on the effects of the drug as well as how the drug is metabolized and eliminated.

With homeopathy, if the effect is stronger the less you take, how is it that users don’t overdose when they stop taking it? The fact is, an “overdose” of homeopathy is impossible to demonstrate.


The appropriate dose of a drug gives the desired effects without side effects. There is a relationship between the dose of the drug, and the response that we see. The dose-response curve illustrates this. Drugs may be dosed at a fixed amount, a specific dosage based on weight, or in the case of cancer drugs, based on your body surface area. The dose-response relationship is fundamental to drug dosing. Depending on the drug, doses can range from a few micrograms to several grams.

Homeopathy is dosed the same way, regardless of the condition or product: Usually five tablets, three times per day. Why? Because every homeopathic product is exactly the same.


The underlying principles of homeopathy are ludicrous and have been definitively refuted by the last two hundred years of scientific advances in medicine and drug design. Given the manufacturing process of infinitesimal dilution, homeopathic remedies are all placebos. And when we look at the clinical studies, it’s exactly as we would predict for a placebo: Virtually all negative trials with the occasional positive trial. Looking at all of the research done on homeopathy since Hahnemann’s time, there is no illness for which homeopathy has been demonstrated to have any objective beneficial effect.  While science and medicine continues to advance, homeopathy continue to try to “balance the four humors” with placebo therapies.

Dr. Steven Novella summarizes homeopathy well:

“Given the lack of plausibility and lack of compelling evidence for efficacy, homeopathy is a scientific dead end. It survives only because of cultural inertia, dedicated practitioners and believers who are not science-based, financial motivations, and ineffective quality-control regulations.”

The Pharmacist’s Role

What should the pharmacist’s role be in the sale of homeopathic products?  Considering a pharmacist’s understanding of how drugs work in the body, and their ability to actually review the data, it’s reasonable to conclude that most pharmacists should have a hard time accepting homeopathy as a legitimate therapy.  Pharmacists that accept homeopathy as plausible (perhaps based on anecdotal reports from patients), yet accept the science of real drugs, are able to move past this cognitive dissonance. Essentially they concede to practice with two sets of standards: one for real drugs and another for homeopathic products.

For the pharmacist that accepts the science-based argument that homeopathy is a grandiose set of placebo therapies, is it acceptable for him/her sell a product that contains no active ingredient and has been repeatedly demonstrated to be ineffective? No. Pharmacists should provide factual and honest information about the products they offer.  To induce a placebo effect with homeopathy, the pharmacist must withhold information on formulation and efficacy. Pharmacists owe patients the responsibility to provide products for which an appropriate risk/benefit ratio exists. When there is no possible benefit achievable, there is no conceivable rationale to recommend a homeopathic product.

Should homeopathic products be sold in pharmacies, but with the appropriate cautions? No. Selling homeopathic products in pharmacies provides an implied endorsement of homeopathy. If a real drug was discovered to contain no active ingredient, it would be recalled from stores – even if patients insisted it was working. Why then, do pharmacies continue to sell homeopathic products?  With pharmacists seeking expanded roles in the healthcare system, the last thing we should be selling is 19th century quackery. Homeopathy should be an embarrassment to pharmacy regulators who have minimum required spatula counts for the pharmacy, but no prohibitions against the sale of elaborate placebo systems. In Britain, there are calls for pharmacists to be required to inform patients that homeopathy has no effects beyond placebo.

Should pharmacists or pharmacy students be taught about homeopathy? Here we are begging the question, assuming that homeopathy is a practice in which one can become educated, implying it’s possible to gain some level of skill or expertise in the practice. But given that homeopathy contradicts our current understanding of human physiology, biochemistry, pharmacology, and the principles of science-based medicine, how can there be any evidence base upon which we can inform pharmacists?

If you’re  a pharmacist or consumer unhappy with the sale of homeopathic products in pharmacies, bring your objections to the attention of the pharmacy manager/and or owner. Describe the ethical problems (and bad optics) of homeopathic products in pharmacies.  You may want to tell your provincial or state pharmacy regulator that pharmacies should sell products that are science-based.  (Here’s a list of Canadian pharmacy regulators, and American pharmacy regulators.)

For more information

For a more expansive analysis of homeopathy, I refer readers to the detailed series by Kimball Atwood at Science-Based Medicine.  See part one, two, three, four, and five. Skeptoid also does a superb and succinct deconstruction of  homeopathy. Quackwatch has an excellent summary, appropriately titled, Homeopathy, the Ultimate Fake. Sense about Science, a UK-based charitable trust, has an PDF handout that debunks homeopathy and provides a good explanation of the placebo effect.

13 thoughts on “The Cognitive Dissonance of Homeopathy

  1. Just discovered your blog – via Dr. Rachel Dunlop’s Skeptic’s Book.

    It’s nice to see a Canadian presence in the skeptic blogosphere.

    I always thought that homeopathy would be less popular if they called it what it really is: “magic water.”

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  11. Laughable – drug sellers invoking ethics. Homeopathy’s ‘less’ cannot agree with those who earn a brilliant living from ‘more’.

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