Risks range from slight temporary redness, bruising, or an allergic reaction all the way to something called a vascular occlusion where the product is injected into a blood vessel. It’s very important to have someone with an intricate knowledge of the anatomy of the face perform this procedure on you for this reason. In the event of an occlusion, there is a reversal agent for HA filler, but you need someone who has a good understanding of what is going on and how to treat the situation.