Dr. Chang believes that acupuncture is such a powerful tool in healing that he says it must be effective immediately after treatment. You are to know progress in 15 minutes. If one does not see results on the first treatment, one must re-learn acupuncture. It is highly accurate and is used for all ailments one can have in daily life. It must be remembered that it has been with us for 4,000 years. Doctors of Oriental Medicine have had to know everything because they were the main source of medical care in many countries of the world. Dr. Chang has complete faith and competence in treating ailments with acupuncture and herbology.