Acupuncture needles are much thinner than the regular needles used to inject substances like vaccines or insulin. The needles are so fine, that when an acupuncture needle is inserted into the skin many patients feel only a mild sensation – or nothing at all! The amount of sensation varies between different point locations on the body and different people’s sensitivity level. It is essentially a painless experience, and is not stressful, even for people who dislike needles.