During a lip flip procedure, Neurotoxin (Botox) is injected to the border of the upper lip.
Once Botox kicks in (up to 2 weeks), the muscles surrounding the upper lip will have relaxed allowing more of the pink of your upper lip to become visible. This is especially great if you find that your upper lip tends to disappear when smiling with teeth.
A lip flip is a great alternative to lip filler. Not only is it less painful, it is also a quicker procedure. Some even call it the "cheap filler" as it is very cost effective compared to traditional lip fillers.
In addition, the lip flip is a procedure that does not come with much of the various risks dermal fillers are known to accompany (such as bruising, arterial occlusions, blindness and necrosis).