Do you guys inject air into your HCG bottle to relieve the vacuum created after drawing out liquid? I don't know if the vacuum hurts it or if unpure air in the bottle would hurt it?
bottle? I dont know about that maybe vial or amp?i dont know how to explain it to you. But, if enough pressure to the vial, the plunger will draw back automatically along with liquid.
Take your syringe and draw down air to the exact amount you will be injecting. With the bottle's rubber stopper facing up, inject the air down into the bottle/vial of HCG. Turn the HCG bottle upside down and draw back the same amount of liquid HCG and remove needle. Now everything is in equilibrium.