Lip augmentation is a common type of cosmetic procedure that gives the appearance of fuller and plumper lips. Injectable dermal filler is most commonly used for this procedure. There are many types of fillers, but the most widely used include a substance similar to hyaluronic acid, which is a natural substance found in the body. Since hyaluronic acid is naturally occurring, allergic reactions are very unlikely. The doctor will mark the lips where the injection will be made. Though recovery is faster than a surgical procedure, there may be bleeding, swelling, bruising and redness and tenderness at the injection site.