Greetings. Depending on the defect perceived - the filling effect to the lips may be given by using filler agents - such as hyaluronic acid. The effect of fillers usuallly last for 4 to 6 months and repeated timelyy sessions may be needed to maintain the look - however over a few sessions the appearance improves and becomes long lasting due to deposition of connective tissue in the areas where filler is injected. Hope this helps - see a qualified dermatologist near you, Warm regards, Dr Govind Suresh Mittal