The take home message from our experiments was more subtle than this. Some homeopathic reports in the literature, including some of the most famous ones by Jacques Benveniste and colleagues, involved sensitive in vitro experiments where the activities being measured could be affected by small changes in the solutes or ions present in the homeo preps. These factors were unknown to these researchers, and were not controlled for. It is quite likely that many of the previously reported in vitro effects of homeo preps were due to the solutes dissolving from the glass vials used to make them. We found that the starting solutes made no difference in the amount of glass-derived compounds that leached into the water, and the number of dilutions also had no effect. Each new vial used to make homeo prep dilutions leached a touch of glass into the water. Clearly, this is not what homeopaths thought they were doing, and it has nothing to do with molecular memories being retained in pure water.
The most likely explanation for the perceived efficacy of homeopathy is the well documented placebo effect. Contrary to popular notions about the placebo effect meaning that there is no real effect, the ability of a pill containing no active ingredients to reduce symptoms of discomfort or stress are legendary in the pharmaceutical industry where many actual medications fare only slightly better than sugar pills in clinical trials. The placebo effect has been known and exploited for centuries. In reference to the placebo effect, Samuel Clemens (Mark Twain) once noted in the 1800s that, "No one doubts - certainly not I - that the mind exercises a powerful influence over the body. From the beginning of time, the sorcerer, the interpreter of dreams, the fortuneteller, the charlatan, the quack, the wild medicine-man, the educated physician, the mesmerist, and the hypnotist, have made use of the client's imagination to help them in their work. They have all recognized the potency and availability of the force. Physicians cure many patients with a bread pill; they know that where the disease is only a fancy, the patient's confidence in the doctor will make the bread pill effective."
Just like the bread pill, giving a small amount of water to a patient with some nagging discomfort certainly can't hurt, and who knows, it might kick in that old faithful placebo effect.
PubMed article link: http://www.ncbi.nlm.nih.gov/pubmed/20129173