When injecting toxin, there is pressure generated in the syringe and needle and this pressure needs time be released. When a needle is removed too quickly from the injection site the vacuum inside the syringe and needle may still be compressed which can cause dripping. Thin needles from 32G and up result in significantly less discomfort and reduces the risk for bruising compared to 30G needles, but the time for this pressure to be released takes slightly longer.
3 tips to prevent needle dripping
Prevent or remove air bubbles
When drawing up your toxin from the vial it is important to prevent any air bubbles inside your syringe or injector. A solution to minimize the risk of absorbing air bubbles is to use a large gauge vial access needle to draw up the toxin dilution. After Penetrating the rubber seal from the glass vial using the vial access needle, hold the vial upside down for possible air bubbles to escape and gently withdraw the toxin. In the case that any air bubbles enter the syringe or injector, carefully inject some dilution back into the vial until all air bubbles escape and repeat withdrawing.
Wait 2 seconds before withdrawing needle
To prevent needle dripping after removing the needle from the injection site wait for the pressure to equalize. Two seconds is normally sufficient time for the pressure to equalize before the needle is safely withdrawn.
Release thumb from plunger thumb rest
When withdrawing the needle from the injection site it is important to release your thumb from the plunger thumb rest . This allows the pressure inside the syringe to be released, and it prevents the plunger to be accidentally pushed forward.