Homeopathy doesn't work

After my recent post on the antivax movement I thought i'd comment on a pet peeve of mine: homeopathy.

What is homeopathy?

First of all, homeopathy is NOT the same thing as herbal medicine. Depending on the particular herb, herbal remedies have actual biologically active effects on the human body.

Homeopathy is a system of "medicine" based on a few principles:

1. "Like cures like"
   Homeopaths find substances that cause the symptoms they want to treat (for example, they use caffeine for insomnia) and use this as the basis of their "remedies". Note however that this is not an internally consistent belief system: it is common to see homeopaths prescribe homeopathic st johns wort for depression for example (and plain st johns wort is an antidepressant - so according to homeopathy, homeopathic st johns wort should CAUSE depression).
   
2. "Law of Infinitesimals"
   Homeopaths believe that their remedies are stronger the more diluted they are, they dilute the original substance by a huge amount until there's essentially no detectable levels of the original molecule left, just water. They claim that the water has "memory" of what was in it. This water is then either sold directly or dripped onto sugar pills which are then sold.

Why it can't work

Basically what you're actually consuming when you take a homeopathic "remedy" is plain water (sometimes with ethanol added) or sugar pills. There is not enough of the original compound left to cause a biological response, and if there was it would be a negative one.

Homeopaths claim the "water memory" means the body can respond to the homeopathic "remedy" in some form, but if this were true we would all be getting all the homeopathic remedies we need from tap water.

Why it seems to work

A lot of people swear homeopathy works, and from their viewpoint it looks like it does. However, the reason for this is that with simple self-limiting conditions they often resolve by themselves without medical treatment. Combined with the placebo effect this is sufficient to explain the odd case of people apparently being healed by homeopathy.

To date, no well-run study has found a distinction between homeopathic remedies and plain water or sugar pills. There is no difference from placebo.

Not convinced?

If you can detect the difference between plain old water and a homeopathic remedy, contact James Randi and you can claim 1 million dollars. If you can not detect the difference however, you must concede it is mere placebo.