The level of pain experienced during a lip filler treatment can vary depending on several factors, including the individual's pain threshold, the amount of filler being injected, and the technique used by the injector. Typically, patients may experience some level of discomfort during the procedure, such as a pinching or burning sensation as the needle enters the skin. However, the discomfort is usually temporary and can be minimized with the use of numbing cream, local anesthetic, or ice before the treatment. Many patients report that the results of the lip filler treatment outweigh any temporary discomfort during the procedure.