After the juice is loaded into the syringe you remove the bubbles by pushing a small amount thru the pin. A small bead appears at the tip. Let this bead run down the pin while twisting the syringe allowing the juice to lubricate the pin. Do it again with another bead. The pin is now "oiled" and slides into the injection site with less effort and pain. When the injection hurts a couple of hours afterward, it could mean there was tissue damage during the injection--moving the pin instead of holding it steady. Take a Tylenol and do better next time.