IzH: Dear Dr. Cartwright, you have been involved in basic homeopathic research for many years and have tested a test system in several studies that can detect homeopathic high potencies in solvents. What is this about?

Dr. Cartwright: The detection system we use is based on solvatochromic dyes. These are electronic dyes that are very sensitive to their environment and respond to changes in solvent polarity, ambient electric fields and changes in pH amongst other agents and solution conditions. We have used around 50 different dyes and they all respond to potencies, often in different ways.

IzH: What exactly does the test measure?

Dr. Cartwright: When a potency is added to a solution of a solvatochromic dye the spectrum of the dye subtly changes. As these dyes absorb in the visible region of the electromagnetic spectrum the effect of potencies can be tracked fairly easily using a standard UV-vis spectrophotometer. What we have found is that potencies seem to polarise the dyes in the same way that an electric field does, so we have come to the conclusion that potencies possess some kind of electric field.

IzH: How did you come up with this test procedure?

Dr. Cartwright: I was looking for some kind of non-invasive way of detecting potencies that didn’t involve magnetic fields (NMR), UV light or other agents that might inactivate potencies even before one had a chance to measure them. Some kind of dye that was actually in solution along with the potency and reporting back to the experimenter what the potency was doing in solution seemed a gentle and practical way of studying potencies. I then came across solvatochromic dyes and realised they were ideally suited for what I had in mind. 

IzH: How specific are the tests?

Dr. Cartwright: Solvatochromic dyes will detect a number of different kinds of agents/conditions in solution such as changes in solvent polarity, ambient electric fields and changes in pH as I said earlier. It is necessary therefore to make sure that conditions are the same in controls and samples – so same pH, same purified water etc., the only difference being that in controls plain water is added and in the test solution potency is added.

IzH: Have these tests been independently verified and how stable are the tests?

Dr. Cartwright: Professor Leoni Bonamin’s group in Sao Paulo, Brazil have been using solvatochromic dyes for over 5 years now and we have published several papers together on their use in detecting homeopathic potencies, both in the laboratory and in the natural environment. I work more looking at what solvatochromic dyes can tell us about the fundamental nature of homeopathic potencies and Prof. Bonamin is looking more at using the dyes in agricultural and aquatic environments to track potencies in water courses and in the treatment of cattle and other farm animals. Sheffield University chemistry department in the UK are currently also running experiments to see if they can replicate results with solvatochromic dyes.

IzH: From your point of view, what conclusions can be drawn from these tests about the possible mechanism of action of homeopathic medicines?

Dr. Cartwright: It is too early to say yet. From the experiments we have done so far we can say a number of things about potencies – they appear to possess an electric field of a comparable strength to the potential difference across cell membranes; they are polarising agents affecting dissociation constants; a weak electric current appears to abolish potency activity, whereas a static magnetic field enhances activity; macrophages (and possibly all living systems) amplify potencies; we found Phosphorous 30 spreads through a large lake system in Brazil faster than the flow of water suggesting the propagation of phos 30 happens independently of the water in which it is placed and finally we have found that Arsenicum 10M decayed according to first order kinetics on interaction with target systems. In other words, we know a lot more about potencies than we did but still not enough to put forward a testable hypothesis as to their physico-chemical identity. More experiments are needed, but I am confident we will get there!

IzH: How did you get into homeopathy research in the first place?

Dr. Cartwright: I was originally a research biochemist at Oxford University and it is there that I accidentally came across homeopathy. I was intrigued to find out more and eventually trained as a homeopath. I always wanted to try and find out how homeopathy worked, but it was years later that I managed to secure funding to carry out fundamental research and I have been lucky enough to have been supported ever since.

IzH: A look into the future – how could homeopathy research continue?

Dr. Cartwright: I think in general terms we need to stop jumping to conclusions as to how homeopathy might work. There has been a long history of doing precisely that, from the memory of water hypothesis, quantum entanglement, stochastic resonance, zero-point energy and more recently nanoparticles. None of these hypotheses have the evidence to support them and they often ignore any evidence to the contrary. We shouldn’t cherry pick evidence to fit a theory and we certainly shouldn’t twist evidence to fit a theory! If the evidence doesn’t fit, drop the theory! I also think there are far too many speculative theories as to how homeopathy might work. We need to step back and use the tools we have that we know have provided and continue to provide evidence such as NMR studies, thermodynamic studies, solvatochromic dye work and self-assembling structures in evaporating droplets. Let’s continue to amass evidence through intelligent and directed questioning until we have eliminated the impossible and we are left with the correct answer, however implausible or unbelievable that might be! We almost certainly will not be able to explain homeopathy using current ways of thinking and only following the trail of evidence will lead to the profound shift in understanding that is needed.

IzH: Thank you for the interview!

Dr. Steven Cartwright

Steven Cartwright holds a PhD from the University of Edinburgh in molecular biology. After 10 years at the universities of California Santa Cruz and Oxford developing techniques in cryoenzymology, he went on to train in homeopathy. Dr Cartwright has been carrying out basic research in homeopathy using solvatochromic dyes since 2010. He runs the Cherwell Laboratory for Fundamental Research in Homeopathy in Oxford dedicated to understanding the physico-chemical nature of homeopathic potencies and has published extensively on the subject. He can be contacted at steven.cartwright@oxford-homeopathy.org.uk

Selected References

Cartwright SJ. Solvatochromic dyes detect the presence of homeopathic potencies. Homeopathy 2016; 105: 55-65.

Cartwright SJ. Interaction of homeopathic potencies with the water soluble solvatochromic dye bis-dimethylaminofuchsone. Part 1: pH studies. Homeopathy 2017; 106: 37-46.

Cartwright SJ. Degree of response to homeopathic potencies correlates with dipole moment size in molecular detectors: Implications for understanding the fundamental nature of serially diluted and succussed solutions. Homeopathy 2018; 107: 19-31.

Cartwright SJ. Using the unique spectroscopic properties of push-pull molecular systems to investigate homeopathic potencies. In: Transdisciplinarity and Translationality in High Dilution Research. Signals and Images GIRI Series; Bonamin, L.V., Waisse, S.; Cambridge Scholars Publishing: Cambridge, UK, 2019; vol. 1, Chapter 7, p. 104-127.

Ana Carla Caparica Aparicio, Jefferson de Souza Silva, Larissa Helen Silva de Oliveira, Sandra Augusta Gordinho Pinto, Hannah Maureen G. Mota, Ivana B. Suffredini, Steven J. Cartwright, Leoni V. Bonamin Physical-chemical analysis of different homeopathic medicines using solvatochromic dyes as indicators of solvent dipole moment changes. In: Proceedings of the 4th HRI International Conference; London; June 13–16, 2019: Abstract P008

Cartwright SJ. Homeopathic potencies may possess an electric field (-like) component; evidence from the use of encapsulated solvatochromic dyes. Homeopathy 2020; 109: 14-22.

Bonamin LV, Pedro RRP, Mota HMG, Aguiar MSC, Pinto SAG, de Souza J, de Oliveira LHS, Aparicio AC, Peres GB, Suffredini I, Dutra-Correa M, Cartwright SJ. Characterization of Antimonium crudum Activity Using Solvatochromic Dyes. Homeopathy. 2020 May;109(2):79-86.

Aparicio ACC, de Oliveira LHS, Silva JS, Coelho CP, Pinheiro SR, Souza MF, Suffredini IB, Cartwright SJ, Bonamin LV. Interaction between Solvatochromic Dyes and Water Sampled from a Natural Source Treated with High Dilutions of Phosphorus. Homeopathy. 2020 Aug;109(3):126-132.

Pinto AAG, Nagai MYO, Coimbra EN, Mohammad SN, Silva JS, Von Ancken A, Pinto SAG, Aguiar MS, Dutra-Correa M, Hortellani MA, Miranda A, Sarkis JES, Suffredini IB, Peres GB, Bernardi MM, Cartwright SJ, Bonamin LV. Bioresilience to Mercury Chloride of the Brine Shrimp Artemia Salina after Treatment with Homeopathic Mercurius Corrosivus. Homeopathy. 2021 Nov;110(4):244-255.

Cartwright SJ. Immobilisation of Solvatochromic Dyes on Transparent Cellulose Films: An Improved Method for the Study of Homeopathic Potencies. Homeopathy 2023; 112; 125-134.

Nagai MYDO, Mohammad SN, Pinto AAG, Coimbra EN, Peres GB, Suffredini IB, Bernardi MM, Tournier AL, Jerman I, Cartwright SJ, Bonamin LV. Highly Diluted Glyphosate Mitigates Its Effects on Artemia salina: Physicochemical Implications. Int J Mol Sci. 2023 May 30;24(11):9478.

Cartwright SJ and Pinkus T. Evidence from the use of solvatochromic dyes indicates that bulk pure water does not potentise. Homeopathy:  in press.