Illnesses could be cured by taking a homeopathic dose of a substance, which if the full strength version of that substance were to be taken by a relatively healthy person, would actually produce symptoms like those in the ill person. We call it Like, cures, Like.
For example, Ipecac is a plant in brazil that if eaten in large quantities can cause diarrhea. In a person with diarrhea, homeopathic ipecac can be a cure.
Homeopathy stimulates the Vital Force in the way in which it needs to be stimulated in order to bring about healing. The exact homeopathic chosen is chosen to work in the exact same way the body is programed to work; we see a problem, we find the solution.
There are no side effects of the homeopathy, only effects of how the homeopathic is stimulating the Vital Force. This may mean that the Vital Force needs to stir up the pot before it can calm down again and that is ok. It is the body healing from the deepest compartment as possible, some times it looks a little ugly at first.