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Highland frogs: metamorphosis 
Editorial 2013
Experiments 1990
Repetition 2002
Repetition 2010
Repetition 2012
Metaanalysis 2013
Raw data

Highland frogs: climbing activity
Experiments 1991
Repetition 1993

Lowland frogs: metamorphosis
Metanaalysis 2012

Further links
Bibliometric study
Expedition report 
Anthology “Ultra High Dilution”

Research contact
Interuniversity College  


Amphibians and extremly diluted thyroxine

Aim: To document an international multicentre research project including inter-laboratory and independent repetition of experiments on the effect of highly diluted thyroxine on the metamorphosis of highland amphibian larvae. Research papers (see links) were published in peer reviewed, mostly PUBMED / MEDLINE listed journals, with impact factors up to 4.5.

Methods: Thyroxine was used because this hormone plays a key role in amphibian metamorphosis. Starting from a dilution of 10-4 parts by weight of tetra- iodo-thyronine sodium pentahydrate , the substance T30x was obtained by 26 successive steps of tenfold dilution in pure water, followed by vigorous agitation and was tested versus analogously prepared water (W30x). Grass frog rana temporaria were taken from alpine biotopes and were treated with T30x or W30x from the 2-legged stage on by adding 3microL of probes per animal to the basin water at intervals of 48h. Two end-points were considered: first, entry into the 4-legged stage, and second, tail reduction. All experiments were performed blind.

Experiments were performed since the early 1990s by the initial team (P. C. Endler, based at that time at Graz University and W. Scherer- Pongratz at the Graz Boltzmann Institute ) and by independent researchers (R. van Wijk from Utrecht University , H. Lassnig from the Federal Institute of Veterinary Medical Investigation Graz , C. Zausner-Lukitsch from Vienna University , G. Bach of KIKOM, Bern University and B. Harrer from Patienteninformation fuer Naturheilkunde Berlin ). A total of 22 sub-experiments were performed, each involving 60–100 animals per group, 15 by the initial team and 7 by the 5 independent researchers.

Results: Independent  Metaanalysis shows that in most sub-experiments – the sole exception being two performed and reported by the initial team themselves – a trend was found of T30x-animals being slower (up to 6 h within 3 days) than W30x-animals. Pooled T30x values obtained by the initial team were 10.4% smaller than W30x values (100%) ( p < 0.01 and d > 0.8), and pooled T30x values from the 5 independent researchers were 12.4% smaller (p < 0.01 and d > 0.8), i.e. differences between groups were statistically highly significant and the effect size was large in either case. Analogously, the number of animals entering the juvenile stage with reduced tail was smaller for T30x than for W30x. For details, see Experiments 1990 , Repetition 2002 , Repetition 2010 , Repetition 2012 .

Conclusion: A metamorphosis hormone diluted beyond Avogadro’s limit using a process of stepwise dilution and agitation according to instructions of homeopathy produced a clear trend of metamorphosis inhibition. This was observed by and raw data were made accessible by 7 researchers from Austria , Germany , Switzerland and the Netherlands .

Annotation: Similarly, experiments on climbing activity of highland frogs were repeated within the team . A detailed account of the difficulties when using lowland animals , a bibliometric survey on the international state of repetition of fundamental research experiments , a backstage report and an anthology “Ultra High Dilution have been published previously. The authors are interested in an open-minded interdisciplinary discussion of results and research strategies.