Hyaluronic Acid: These fillers are the most popular and are often used for lip injections, cheek augmentation, and nasolabial folds. Calcium Hydroxylapatite: These fillers are used for deeper wrinkles and folds, such as marionette lines and nasolabial folds. Poly-L-Lactic Acid: These fillers are used to stimulate collagen production and are often used for areas such as the cheeks and chin.