Today, substances such as hyaluronic acid, calcium hydroxyapatite, polycaprolactone and poly-L-lactic acid are used for filling purposes. Among them, hyaluronic acid is the most commonly used, and it is used in almost every region of the face. Nose, lips, cheekbones, chin and jaw-line, nasolabial lines, marionett lines, temple, orbital groove and forehead are the application areas. Filling applications must be done by specially trained physicians in places with health institutions (such as hospitals, polyclinics and clinics). Be sure to ask your doctor about the brand of the filler used, the expiration date and the sticker containing the Lot number and keep it. It is very important to know about the previously used filler material for the next application.