Library Simple Science
Click to enlarge Click to watch video Click to follow link

The word 'homeopathy' is familiar to many, often used to describe a type of therapy based on the use of substances in very low concentrations. But is it really so? What is homeopathy and what are its basic principles? What are ultra-low doses of a substance? We will try to answer all these questions in this article.


There are three basic principles of classical homeopathy as a matter for scientific inquiry. The principle of similarity: treatment by taking a drug which has been shown to cause symptoms and markers similar to those of the disease in healthy people. Dilution and dynamisation: dilution and its subsequent shaking should increase the effectiveness, or 'potency' of the drug. An individual approach: personalised diagnosis and prescription. Source https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1876605/

Homeopathy is a system of alternative medicine, the basic principle of which is the principle of similarity, from the Latin similia similibus curentur: like cures like. In other words, a disease can be treated with substances that cause the same markers and symptoms in a healthy person1. It is no wonder that the term itself comes from the Greek homoios, meaning 'similar', and pathos – ‘suffering’ or ‘disease’2. The origins of this approach can be found in the writings of Hippocrates, about 2,400 years ago1. However, the German doctor Samuel Hahnemann (1755-1843)1-3, who published his Essay on a New Medical Principle2 in 1796, is considered the founder of modern homeopathy.

Hahnemann proposed the term 'homeopathy' and formulated its basic principles. Disappointed with the therapy methods which existed at that time, he began to search for an alternative. According to the official version, while translating a book about plants into German, Hahnemann came across a detailed description of the properties of cinchona, the bark of the tree Cinchona officinalis, which is effective in treating malaria. Hahnemann decided to test the effects that the bark causes on himself. Having taken it as a healthy man, he found that the effects were remarkably similar to the symptoms of malaria1-3. This gave Samuel Hahnemann the idea that he subsequently developed and presented in the form of a universal medical law, calling it the 'principle of similarity'3. For example, according to this principle, strychnine, which causes seizures in healthy people, can be used to treat seizures in patients. Hahnemann formulated this approach to medicine in his book The Organon of the Healing Art, published in 18104.

In those days, homeopathy was a fairly progressive type of therapy compared to contemporaneous treatment methods. There is evidence that during the cholera epidemic of 1854, the mortality rate in homeopathic hospitals was significantly lower than in traditional ones3. Of course, such results may be due to various reasons. For example, the barbaric practices of orthodox medicine of the time, such as bloodletting, and prescribing high doses of laxatives and heavy metals to patients, were not used in homeopathic clinics. Therefore, it was easier to maintain hygiene in homeopathic clinics3.

After studying the symptoms caused by various toxic substances in healthy people (called 'proving' in homeopathy1-3), Hahnemann believed that in order to treat a patient, one only needed to select a substance whose action most closely matched the manifestations of the disease. To reduce the toxicity of such substances, Hahnemann proposed diluting them repeatedly1,3. He then noticed that the drugs he carried to the patient’s house were more effective than the drugs prepared in situ without shaking1. Hahnemann would later hypothesise that successive multiple dilutions, accompanied by shaking, allow the 'vital energy' of the substance being diluted to be released, enhancing or 'potentising' its healing properties3. For this reason, the second principle of homeopathy was formulated - the principle of 'potentisation' or 'dynamisation' 1-3.

In modern homeopathy, decimal (1:10, denoted by the letter X or D) and centesimal (1:100, denoted by the letter C) dilutions1,3 are accepted. This means that a 3X (or 3D) dilution, for example, is a 1:10 dilution repeated three times (the result is a thousand-fold dilution), and a 6C dilution is six times a ratio of 1:99. It should be noted that, based on the limits of substance dilution (it is impossible to 'separate' a single molecule of a substance in a solution during dilution), dilutions higher than 1024 (12С) should not in theory contain a single molecule of the initial substance. However, there are publications in which the active substance is identified in the solution at an even higher degree of dilution11. Various hypotheses about the mechanism of this phenomenon have also been presented in literature11,12.

Another (perhaps the most important) principle of Hahnemann’s homeopathy is an individual approach to each patient. Hahnemann noted that in order to prescribe the right medicine, it is necessary to study not only the specific manifestations of the disease in each patient, but also general condition, constitution, habits, character, lifestyle, and desires. So, despite suffering from what would seem one disease, different people need to be prescribed different drugs2,3. This can be illustrated by the use of homeopathic medicines to treat the common cold. For example, a patient with a cold, whose main symptoms are lacrimation, a burning eye irritation, and clear, transparent discharge from the nose, may be prescribed a preparation of onion extract (Allium cepa), because these symptoms in patients are similar to the effects of onions. However, another patient with thick yellow discharge from the nose, the need for cool, fresh air and hydroadipsia (an absence of thirst) needs to be prescribed pasqueflower (Pulsatilla), because these symptoms are similar to the effects of taking this plant3. Thus, both patients have the same diagnosis (upper respiratory tract infection), but each of them receives different homeopathic remedies depending on their characteristic symptoms.

This approach is called 'classical' homeopathy, and it is practiced in most European countries, India, South America and the USA2. A homeopathic doctor conducts a general medical examination and asks in detail not only about the symptoms troubling the patient (such as when, where and how they appeared, their strength, and duration), but also about their mental, emotional and physical condition. This is the philosophy of homeopathy – treating the person as a whole, rather than treating the symptoms of the disease2,3,5. Therefore, homeopathy can also be considered a kind of psychotherapy5. In the classical approach, after a conversation and an examination, one drug is usually selected for the patient, and its effect is followed up long term1,3. In this regard, the methods of evidence-based medicine, including evaluating the effectiveness of a particular drug in large patient samples, are not applicable.

In addition to classical homeopathy, there are other types. Thus, 'clinical homeopathy', or 'homeotherapy', is based on the simultaneous administration of numerous homeopathic remedies in order to rid the patient of various symptoms of the disease (each symptom has its own medication)2,3.

In this case, one must not confuse homeopathy with phytotherapy and naturopathy (treatment with natural remedies). Phytotherapy drugs contain a rather high (measurable) amount of active substances obtained from plant materials, which means that one of the three principles of homeopathy is violated1. On the other hand, not all high and ultra-high dilutions of substances can be called homeopathic.

It is worth clarifying that 'high' dilutions include preparations with a theoretical concentration of the active substance below 10-12 M (which is less than 1011 molecules of the substance in 1 litre of solution)6, and that 'ultra-high' dilutions include preparations whose theoretical concentration of the active substance is below 10-23 M7. Many researchers have been studying high dilutions of substances and have shown their efficacy in experimental models of various pathologies6,8-10. At the same time, the approach they use is not homeopathic either. High and ultra-high dilutions prepared in accordance with homeopathic technology can be called 'dynamised'7, but they are not homeopathic, since the active substances used for preparation, as well as their doses, are not selected individually by a homeopathic doctor. Also, the prescription of such drugs violates the similarity principle.

Thus, homeopathy is not a vague term for any therapeutic substances in low and ultra-low concentrations, but rather a clear concept of medicine, which has existed and been developed for over 200 years. In addition, it is today one of the most common types of complementary medicine2. Homeopathy's mechanisms of action are still unknown, and sceptics believe that its achievements are due to the placebo effect and 'psychotherapy'. However, whatever the mechanisms, it is the result that is important in therapy, and many patients have noted the positive effect of homeopathy. It has been shown in some clinical trials3. Therefore, increasing public and professional interest in homeopathy demands more thorough and systematic research into its effects.


1.    K. D'Huyvetter, A. Cohrssen (2002). Homeopathy. Primary Care: Clinics in Office Practice, 29(2), 407–418.

2.    W.C. Merrell, E. Shalts (2002). Homeopathy. Medical Clinics of North America, 86(1), 47–62.

3.    W.B. Jonas, T.J. Kaptchuk, K. Linde, (2003). A Critical Overview of Homeopathy. Annals of Internal Medicine, 138(5), 393.

4.    S. Hahnemann Organon of Medicine. Los Angeles: J.P. Tarcher; 1982.

5.    J. Davidson, W. Jonas (2016). Individualized Homeopathy: A Consideration of Its Relationship to Psychotherapy. The Journal of Alternative and Complementary Medicine, 22(8), 594–598.

6.    E.B. Burlakova, A.A. Konradov, E.L. Maltseva (2003) The effect of ultra-low doses of biologically active substances and low-intensity physical factors. Chemical physics. 22 (2): pp. 21-40.

7.    L. Bonamin (Ed.). (2008). Signals and Images. Contributions and Contradictions about High Dilution Research. Springer Netherlands. p. 222.

8.    E.B. Burlakova (2000) Ultra-low doses are the great mystery of nature. Ecology and life. №2. p. 38.

9.    N.A. Tushmalova, L.L. Pragina, E.L. Maltseva, E.B. Voevodina, E.B. Burlakova (2008) The effect of low doses of Polydan on the conditioned reflex of passive avoidance in rats. Bulletin of Moscow University. Series 16: Biology, (No. 4): 3–7.

10.    T.A. Misharina, L.D. Fatkullina, E.U. Alinkina, A.I. Kozachenko, L.G. Nagler, I.B. Medvedeva, A.N. Goloshchapov, E.B. Burlakova (2014) The effect of small doses of essential oils on the antioxidant status of red blood cells in the liver and brain of mice. Applied Biochemistry and Microbiology. 50 (1): pp.101-107.

11.    https://pubs.acs.org/doi/10.1021/la303477s

12.    A.V. Syroeshkin The nature of released activity from the point of view of biophysics // District paediatrician. - 2018. - No. 3. - pp.12-13