How big are those needles, anyway?

They’re not very big. The typical Chinese fine needle measures .25 to .30 millimeters in diameter and 30-50 millimeters in length. Acupuncture needles, unlike hypodermic needles, are neither hollow nor rigid, and the tip is shaped to increase the patient’s comfort during insertion. It has often been stated that anywhere from half a dozen to a dozen acupuncture needles will fit inside the bore of a hypodermic needle; this depends, of course, on the diameter of all needles under consideration. Some Japanese-made needles are quite a bit finer than their Chinese counterparts. Interestingly enough, needle diameter has very little to do with insertion comfort; needling technique and needle tip shape are much bigger factors.