Hematoma from lip injections? What do I do?

A hematoma is possible after lip injections and will eventually resolve. It is not dangerous. I would treat with oral arnica and a vascular laser to shorten the duration of the bruising. Using cannulas will decrease the risk of this as well as an experienced injector.

Bruising is fairly common after injectables, especially in areas that have a lot of blood vessels such as the lip.  We take especial care for this reason to take precautions that minimize bruising, and have had a great deal of success with limiting or even eliminating this.
However, once bruising does occur, a little pressure immediately after the injection can reduce the amount of spread.  If there has been some time that has passed, alternating warm and cold compresses can sometimes help speed up your body's process of absorbing the hematoma.  Ultimately it will go away on it's own.