There is no evidence that rubbing oil on your head will cure cancer, therefore it is not paid for on the NHS. Similarly there is no evidence that Homeopathy works, therefore it should not be paid for on the NHS, unfortunately it is.
Homeopathy has been proven not to work, if it did a whole new force would have been discovered, not just in medicine but in physics. The person who discovered this force would have won a Noebel prize. Unfortunately it has been proven not to work. End of story
Whats more relevant and interesting is discussing whether or not doctors should be able to prescibe a placebo. There is some cognitive dissonace on the topic within the medical professions. One one hand we are against it (we would be deceiving patients, they would not be fully informed) but there again somedoctors are quite happy with there patients trying out alternative medicines and not telling them about the placebo effect.