Is homeopathy really just a placebo? Can it be harmful?

First things first: Defining what the question is about.
Let’s start with: Homeopathy

Hahnemann’s concept

Homeopathy goes way back to the year 1796 and was created by the German physician Samuel Hahnemann. He studied medicine in Leipzig and Vienna. In 1790 he was translating the work of a fellow physician William Cullen’s “Lectures on the Materia medica” into German. While doing so he questioned whether cinchona (a plant) really does cure malaria. He ingested some bark of the plant and experienced similar symptoms to those of malaria itself (fever, shivering, joint pain).
From this he concluded that for a remedy to be effective it must produce symptoms in a healthy individual that are similar to the diseases that they treat.

“similia similibus curentur” – “Like cures like.”  [1]

This is a postulate, not a scientific law. As it was shown in later scientific work, cinchona contains quinine which kills the parasite that causes malaria. [2]
Homeopaths claim that Hippocrates may have originated homeopathy (400BC) and that it  was later also “used” by Paracelsus as he also declared “what makes a man ill also cures him”. [3] But Hahnemann gave homeopathy its name and principles and defined the process of making homeopathic remedies. He wrote down all his ideas in a book “Organon of the Healing Art” which is considered the homeopathic doctrine. You can find a good overview of the paragraphs here.

Preparation of homeopathic remedies

Hahnemann started tests to prove his postulate. Experimental subjects ingested substances and Hahneman recorded all of their symptoms and the condition under which they appeared.
He believed that a large dosage of remedies that cause similar symptoms to the sickness would only make the illness worse. Therefore he advocated that the substance must be extremely thinned.
He invented the technique of making these dilutions – the so-called dynamisation” or “potentisation. Homeopaths believe that a solution that is more dilute has a higher potency and is therefore stronger and deeper-acting. [4]

This contradicts scientific findings as it was proven that substances have a stronger activity the higher the dosage is. [5] Real-life example: Drinking 3 glasses of wine will get you more drunk than taking one sip.

In the process of “potentisation” the substance is diluted with alcohol or distilled water, then vigorously shaken (“succession”). Insoluble solids are diluted by grinding them with lactose (trituration).
Hahnemann invented a potency scale to determine the dilution of the substance.
He created the centesimal or “C scale”, where substances where diluted by the factor of 100 at each stage – meaning that a 2C dilution had to be diluted by the factor of 100 two times. Hahnemann mostly advocated 30C dilutions. [4]

s=substance, w=water; after first dilution 1 molecule s and 99 molecules w (1:100)

Given Hahnemann’s time, it was reasonable to assume that preparations could be diluted indefinitely. But as we know better nowadays the smallest possible unit of a chemical substance is an atom or molecule.
This means that at some point there will be no molecules left in the dilution. At 12C there’s a probability of 60% that the dilution still contains 1 molecule of the original substance if one mole (=6,022 · 10^23 molecules) of the original substance was used.
How do we know that?
A quick calculation: Let’s say one starts with 1mol/L and then dilutes to 12C (=1*10^24)
6.02×10^23/1×10^24 = 0.6 molecules per liter –> therefore a 60% chance of finding a molecule (because molecules don’t come in halves and thirds)

So in a 30C dilution – which was advocated by Hahnemann – it would take two billion doses per second to six billion people for 4 billion years to have one of the individuals take in one molecule of the original substance.
Other scales were developed by other homeopaths: for example the decimal scale D or X (diluting by the factor of 10)
Diluting the substance, Hahnemann found out, reduced potency and side-effects. He claimed that succession (“Schütteln”) nullified this and gave the dilution back its activity. [4]

Homeopaths propose the explanation that the water retains some “essential property” of the original substance because the preparation has been shaken after each dilution. Hahnemann believed that by dynamizing or shaking the dilution a “spirit-like”-healing force was released from within the substance, also proposed as the concept of “water memory”. No supervised experiment under controlled conditions has been able to prove this. [5]
The process of making homeopathic pills requires an inert substance (often sugars, typically lactose) upon which a drop of liquid homeopathic solution is placed and then allowed to evaporate. [4]
Most homeopathic dilutions don’t contain any objectively detectable active ingredient. In some cases, with low dilution (X, 2X) there can be a pharmacologically active dosage.


One of the most important steps in homeopathic treatment is the consultation – a lengthy process where the homeopath takes a very detailed patient history. This includes: physical, mental and emotional state, life circumstances, physical or emotional illnesses. The homeopath tries to match all the patient symptoms with a substance that would cause the symptoms in a healthy person.

In Hahnemann’s words:

“For the physician, the totality of the symptoms alone constitutes the disease” §9[4]

“The totality of the symptoms is the sole indication to govern the choice of the remedy” §13[4]

“When all symptoms have disappeared the disease is cured” §11[4]

What does that mean?

First: Only the symptoms “make” the disease.
Problem: One symptom can have various underlaying causes. The disease makes the symptom, but as we only have one body and a limited number of organs and muscles and so on, it is only to be expected that same symptoms will show in many different diseases.
Example: Joint pain can be caused by a “physical cause” in the joint (blockage, break), by psychiatric causes, inflammatory processes in the body, viral infections or simply growing.

Second: Physicians should use the same remedy for same symptoms.
Problem: As stated above, same symptoms show in different diseases. It would be reckless to try to treat two different causes. Even if the disease and cause is the same, doctors have to adjust therapy to individual patients (finding the right dosage, switching drugs or different procedure e.g. surgery)
Example: Fatigue, Joint pain, Fever can be caused by a large variety of diseases/pathogens. Such as viruses, bacteria, auto-inflammatory diseases, anemia, allergies, diabetes, menstruation, acute stress and/or psychiatric disorders. Just by comparing a bacterial infection and menstruation, recommending the same therapy would be reckless.

Third: Once the symptoms are gone, the disease is cured.
Problem: There are many diseases that are symptomless for some time, periodically symptomless or symptomless after (proper) treatment has been started (e.g.: antibiotics – take them to the end). Example: Tumors grow for a certain time before the first symptoms start. Viruses have a different incubation time and some bacterial infections don’t cause any symptoms after antibiotic treatment has started but are still present and would probably start causing symptoms again if not eradicated sufficiently.

On the other hand, homeopaths claim that depending on one’s personality, emotional status or symptom development (“does it get worse when you sleep with the window open or closed?”) different homeopathic remedies have to be given.
When it comes to the postulate “like cures like” it has been general scientific knowledge that cures work either on the cause or support the body in fighting the cause. For example: If we put antibiotics and syphilis causing bacteria in a glass the bacteria will die. Therefore, it works. It does not work because this certain antibiotic would cause “syphilis-like-symptoms” in a healthy person.

Hahnemann himself wasn’t as strict about “like cures like” as he adds: “If, on the contrary, it proves that the most certain and permanent cure is obtained by medical substances that produce symptoms directly opposite to those of the disease, then the latter agents ought to be selected.” §17[4]

So now we have an idea what homeopathy is and how homeopathic remedies are made. The second part of the questions mentions placebos.

What about placebos?

A placebo is a substance or treatment with no active therapeutic effect. [6]
So the question whether homeopathy is a placebo can only be answered if it is compared to a placebo. The thing about science is that it is very precise. So the question cannot be: is homeopathy a placebo. It is: Compared to a placebo does homeopathy show better effects on a “given status”. The golden standard to compare two substances are randomized clinical trials, where a placebo/ standard therapy receiving group is compared to a group that receives homeopathic remedies. The clinical trial can be single-blinded (patient does not know in which group they are) or double blinded (patient and doctor don’t know which group receives what). Meta-analysis then compares different clinical trials.

So what do studies say?

There have been plenty of studies and meta-analysis [7] [8] [9] and the overall summary of serious clinical trials says: homeopathic remedies do not have a better effect than placebos.

Find an exemplary overview of clinical trials here.

Those studies that show a positive effect, indicated after multiple systematic reviews that this is because of chance, flawed research methods, and reporting bias.

Homeopaths mostly have the following point of criticism:

Homeopathic principles were disregarded.
All patients from the homeopath-group get the same remedy. As stated before even though symptoms are the most important guide on what homeopathic remedies to use, it is also important to evaluate personality, emotional status and the change in intensity of patient’s symptoms.
Homeopathy aims to individually treat the “whole” person with individualized remedies and not the disease.

As those principles are disregarded, homeopaths claim that it is no wonder that homeopathic remedies haven’t been proven to work better than a placebo because they would need the things listed above to work. [11]

This literally states that there is no pharmacologically active substance in the homeopathic remedy itself. This means that something more than “just” giving a patient a remedy has to happen so that the remedy works.

But it has worked on me! / I know someone where it worked!

Luckily, science offers plenty of explanations on how homeopathy appears to cure diseases or alleviate symptoms even though the homeopathic preparation itself is inert.

  •  The placebo effect: the aforementioned intensive consultation and expectation for the homeopathic remedy to work may cause the effect.
  • The therapeutic effect of the consultation: Many doctors seem to be stressed and not take enough time for a patient. Homeopaths take up to an hour to care about the patient. They ask about the concerns and the patient experiences a compassionate caregiver that can have a positive effect on the patient’s well-being.
  • Natural healing: As in the body took care of it itself. Time and the body’s ability to heal itself result in many diseases eliminated without receiving medical treatment.
  • Unrecognized treatment: unrelated environmental agent, food, exercise or treatment for a different cause may have occurred.
  • Regression towards the mean: Many disease or conditions are cyclical, meaning that symptoms and general status of the patient may vary over time. Patients tend to seek care when discomfort is greatest. Patients may feel better anyway after some time because they are in a “better” period of the disease’s cycle but because of the timing of the visit to the homeopath, they might link their improvement to that.
  • Non-homeopathic treatment: patients may receive standard medical care at the same time as homeopathic treatment.
  • Cessation of unpleasant treatment: Some homeopaths recommend patients to stop getting medical treatment, such as surgery or drugs, which can cause side-effects. When patients stop getting that treatment, they may misinterpret the lack of side-effects as “improvement”.

But does it cause harm?

There are some homeopathic remedies that involve poisons, such as arsenic, poison ivy or Belladonna but are highly diluted. In rare cases, if there has been improper preparation or intentional low dilution, adverse effects can be seen. Serious adverse effects have been reported such as seizures and death. [12]
There has been arsenic poisoning after using arsenic-containing homeopathic remedies.
A small percentage of users lost their sense of smell after using “Zicam Cold remedy Nasal Gel” – a rather low diluted homeopathic remedy (2X) containing zinc gluconate. [14]

A meta-analysis of clinical trials has found that adverse effects due to homeopathic remedies were reported by patients about as often as they were reported among patients receiving a placebo or conventional medicine. [15]

Answer to the question:

Homeopathy has not been proven to work better than a placebo and is considered a pseudoscience. It can cause harm, in many cases is does not.


Given the facts at hand homeopathy is not more than a placebo. Still, if I had a patient come up with minor issues and the patient knows that their usual intake of a certain homeopathic remedy helps alleviate the symptoms, I would not talk the patient out of it. The placebo effect is not to be underestimated and patient needs and wishes are to be taken seriously.

Homeopathy claims to be treating the patient, focusing on the person and their symptoms, while to some extent leaving out the cause. Something conventional medicine is often criticized for, is  that it ONLY focuses on the symptoms. My experience so far is that it is the other way round.
Homeopathy claims to be able to cure different diseases with the same cure, it claims that once the symptoms are gone, the disease is also gone.
Conventional medicine is more thorough and prescribed medicine is often very specific. There are cases where it is not, is mostly because there hasn’t yet been developed a specific cure. And there are doctors who provide unsatisfying help and care, doctors that are stressed out and don’t take their time with patients. Nearly everyone has experienced that. The answer to that doesn’t lie in homeopathy, it lies in a better health care system and those are two very different things.



As this article discusses pseudoscience and science, those procedures that fall under pseudoscience, are written in cursive. Many words are directly linked to a website, paper or e-books.

Thanks to Birgit Jorda for editing.


[1] The Editors of Encyclopædia Britannica. Biography: Samuel-Hahnemann. Web. 14 Feb. 2018. <>.

[2] Atwood, Kimball. Homeopathy and Evidence-Based Medicine: Back to the Future. Web. 14 Feb. 2018.

[3] Hargrave, John. Paracelsus. 2018. Web. 14 Feb. 2018. <>.

[4] Samuel, Hahnemann. Organon of the Healing Art. Dublin: P. D. Hardy, 1833. <>

[5] Grimes, D. R. Proposed mechanisms for homeopathy are physically impossible. Focus on Alternative and Complementary Therapies. (2017): 149–155. Web. 15 Feb. 2018.

[6] The Editors of Encyclopædia Britannica. Placebo. Web. 15 Feb. 2018.

[7] Shang, Aijing et al.  Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy. The Lancet. (2005) 366.9487: 726 – 732. Web. 15 Feb. 2018.

[8] Ernst, E. A Systematic Review of Systematic Reviews of Homeopathy. British Journal of Clinical Pharmacology. (2002) 54.6: 577–582. PMC. Web. 15 Feb. 2018.

[9] Kleijnen J, Knipschild P, ter Riet G. Clinical trials of homoeopathy. BMJ. (1991) 302:316. Web. 15 Feb. 2018.

[10] National Health and Medical Council. Evidence on the effectiveness of homeopathy for treating health conditions. (2016). Web. 15 Feb. 2018.

[11] Vithoulkas, G. Serious Mistakes in Meta-Analysis of Homeopathic Research. Journal of Medicine and Life. (2017) 10.1: 47–49. Web. 15 Feb. 2018.

[12] Posadzki, P., Alotaibi, A. and Ernst, E. Adverse effects of homeopathy: a systematic review of published case reports and case series. International Journal of Clinical Practice. (2012) 66: 1178–1188. Web. 15 Feb. 2018. <doi:10.1111/ijcp.12026>

[13] Chakraborti, D; Mukherjee, SC; Saha, KC; Chowdhury, UK; Rahman, MM; Sengupta, MK. “Arsenic toxicity from homeopathic treatment”. Journal of toxicology. Clinical toxicology. (2006) 41.7: 963–7. Web. 15 Feb. 2018. <>

[14] Boodman S. “Paying through the nose”. The Washington Post. (2006). Web. 15 Feb. 2018.

[15] Stub, T; Musial, F; Kristoffersen, AA; Alræk, T; Liu, J. “Adverse effects of homeopathy, what do we know? A systematic review and meta-analysis of randomized controlled trials“. Complementary Therapies in Medicine. (2016) 26: 146–63. Web. 15 Feb. 2018.