Dilute Medicines

testtubesBasic homeopathy research has demonstrated that ultrahigh dilutions such as homeopathic medicines are able to cause biological effects that can be seen clearly under experimental conditions1. Theories are steadily being developed about how ultrahigh dilutions, beyond a level where no starting material should conceivably remain, acquire or retain specific physical properties, despite the fact that they do not contain additional molecules.

“The facts are indisputable, statistically significant and reproducible, even if they cannot be explained by the molecular paradigm2

Scientists frequently refer to homeopathic medicines as being diluted ‘beyond Avogadro’s number’. This means that they have been diluted beyond 10(-23) – the final concentration at which molecules of the original substance would still be present. Confusingly several different expressions are used to refer to dilutions beyond this point: ‘high dilutions’, ‘ultrahigh dilutions’, ‘ultramolecular dilutions’ and ‘UHDs’; in homeopathic language they may also be referred to as ‘high potencies’.

Homeopathic medicines of the strength 12c and above are in this ultramolecular range. This is why homeopathy attracts such controversy, with sceptics saying that homeopathic medicines are ‘nothing but water’.

How can such dilute medicines work?
Conventional medical drugs can be described simply as chemicals that interact directly with the body’s biochemistry; as homeopathic medicines are too dilute to contain molecules of the original substances they are made from, we know that they don’t work in this biochemical way and must therefore have an entirely different mechanism of action.

The manufacture of homeopathic medicines involves two processes – dilution andsuccussion, where succussion is a specific form of vigorous shaking. The starting medicinal substance (e.g. plant material) is dissolved in water and alcohol, and then diluted and succussed many times, often to the point where we would expect there to be no molecules of the original substance left. This has led sceptics to say that homeopathic medicines are ‘nothing but water’. Researchers believe that the succussion is an essential component in creating biologically active samples, so experiments investigating homeopathic ultra-high dilutions always use succussed samples. Some experiments even compare diluted and succussed samples to samples that have been diluted to the same level but not succussed, as well as other controls3.

Experimental results from many different independent laboratories have confirmed that there are physical differences between homeopathically prepared samples and control samples (such as plain water or other solvents). These differences can be measured using scientific techniques such as:

  • Calorimetry – measuring the amount of heat given off by a sample4
  • Spectroscopy – measuring how a substance absorbs, emits or scatters electromagnetic radiation5, 6
  • Thermoluminescence – The amount of light produced by a sample when it is heated (due to the release of stored energy) can also be measured7.

A number of theories are also being developed that may go some way to explaining how ultra-high dilutions are not simply water8-10.One such idea, based on quantum theory, has the potential to explain how ultra-high dilutions such as homeopathic medicines can work11. It is thought that the manufacturing process of ultra-high dilutions causes an interaction between molecules of the active ingredient (e.g. plant material) and the water it is dissolved in, creating new structures called ‘quantum coherence domains’. This process effectively imprints information from the active ingredient into the water it is dissolved in, so that even when there are no longer any molecules of the plant left, its characteristics remain in the water.

In 2009 Nobel prize winning virologist Professor Luc Montagnier (known for co-discovering HIV) published the results of a series of experiments investigating the electromagnetic properties of ultra-high dilutions12. His team took samples of biological material such as disease-causing bacteria and fragments of DNA and prepared them in a similar way to homeopathic medicines (i.e. serial dilution and agitation). At dilutions when you would no longer expect molecules to be present (e.g. 10 to the -12, equivalent to a 6c strength homeopathic medicine) the samples gave off specific electromagnetic signals. The researchers suggested that the electromagnetic signals were produced by ‘nanostructures’ created during the preparation process, i.e. tiny new structures formed in the sample by an interaction between molecules of the biological material and the water it is being diluted with.

In an interview for Science magazine when asked, “Do you think there’s something to homeopathy…?” Montagnier replied, “I can’t say that homeopathy is right in everything. What I can say now is that the high dilutions are right. High dilutions of something are not nothing. They are water structures which mimic the original molecules”13.

Can we use medicines we don’t understand?
The experiments and theories described above do not, however, tell us how homeopathic medicines interact with the living body, but the more we learn about the properties of these ultra-high dilutions in the laboratory, the closer we can come to understanding exactly how homeopathic medicines work in practice and how we might go about studying them in vivo and improving current research approaches.

Although we don’t yet know how homeopathic medicines work, homeopaths do know how to use them safely and effectively, which is what really matters to both patients and healthcare providers. We are simply at a stage in homeopathy research when our clinical understanding of homeopathy is ahead of our theoretical understanding.

This situation is not unique to homeopathy; we still don’t know how a lot of commonly-used conventional drugs work. For example, aspirin was used for decades before scientists began to understand its mechanism of action in 1971 and by 2005 only a few of its biological effects had been investigated14.

Experts still don’t know how general anaesthetics work either15. There are various theories, but none that can fully explain how the drugs bring about loss of consciousness. Despite this fact, anaesthetists do know how to use anaesthetics safely and effectively and no-one would want them to be withdrawn while scientists figure it out!


1)  Witt CM, Bluth M, Albrecht H, et al. The in vitro evidence for an effect of high homeopathic potencies – a systematic review of the literature. Complement Ther Med, 2007; 15: 128–138
2)  Van Wassenhoven M. Priorities and methods for developing the evidence profile of homeopathy. Homeopathy, 2005; 94: 107–124
3)  Brack A, Strube J, Stolz P, Decker H. Effects of ultrahigh dilutions of 3,5-dichlorophenol on the luminescence of the bacterium Vibrio fischeri. Biochim Biophys
4)  Elia V, Niccoli, M. New physico-chemical properties of extremely diluted aqueous solutions. J of Thermal Analysis and Calorimetry, 2004; 75: 815-36
5)  Rao ML, Roy R, Bell IR, Hoover R. The defining role of structure (including epitaxy) in the plausibility of homeopathy. Homeopathy, 2007; 96: 175–182.
6)  Roy R, Tiller WA, Bell IR, Hoover MR. The structure of liquid water; novel insights from materials research; potential relevance to homeopathy. Materials Research Innovations, 2005; 94: 577–608
7)  Rey L. Thermoluminescence of ultra-high dilutions of lithium chloride and sodium chloride. Physica A, 2003; 323: 67–74
8)  Bellavite, P, et al. High-dilution effects revisited. 1. Physicochemical aspects.Homeopathy; 2014,103(1):4-21.
9)  Bellavite, P, et al. High-dilution effects revisited. 2. Pharmacodynamic mechanisms.Homeopathy; 2014, 103(1):22-43.
10)  Bellavite P, Signorini A. The Emerging Science of Homeopathy, 2e. 2002: North Atlantic, Berkeley
11)  Preparata, G. QED coherence in matter. (World Scientific: 1995)
12)  Montagnier L et al. Electromagnetic signals are produced by aqueous nanostructures derived from bacterial DNA sequences. Interdiscip Sci Comput Life Sci, 2009; 1: 81-90
13)  Enserink, M. Newsmaker interview: Luc Montagnier, Science, 24 December 2010; 330, 1732 [DOI:10.1126/science.330.6012.1732]. American Association for the Advancement of Science www.sciencemag.org
14)  Dr. Karsten Schrör, Head of the Institute of Pharmacology and Clinical Pharmacology, Heinrich Heine University, Düsseldorf. Medical News Today website Oct 2005 www.medicalnewstoday.com/articles/31435.php
15)  Pleuvry B. Mechanism of action of general anaesthetic drugs. Anaesthesia & Intensive Care Medicine, 2008; 9(4): 152-3