Fillers add volume and contour to facial features: cheeks, midface, nasolabial folds, marionette lines, and lines around the lips. They are best thought of as injectable implants rather than as a treatment for the skin itself.
The most widely used products are hyaluronic acid gels, hyaluronic acid being a substance that occurs naturally in the body. Products differ mainly in the degree of cross-linking, which determines how firm the gel is and therefore how deep it should be placed.
Matching product to layer
Firmer, more cross-linked gels are designed for deep midface placement, where they enhance the zygomatic arch and maxillary prominence, add projection, reduce the prominence of the tear trough and provide subtle lift. The same category of product can be used to lift and fill the nasolabial area.
Softer formulations are placed in the mid to deep dermis for moderate to severe folds, and lighter ones again for perioral wrinkles. Placing a firm product too superficially, or a soft one too deep, is how filler starts to look like filler.
Risks and reversibility
Risks are generally minor: inflammation, swelling and bruising at the injection sites, with mild redness, tenderness, a lumpy feel, firmness or itching also possible. The treatment area is cleaned with antiseptic beforehand, and infection is rare. Allergy is likewise rare.
One practical advantage of hyaluronic acid products is that they are reversible: injection of hyaluronidase dissolves them. For anyone new to fillers, that reversibility is a reasonable argument for starting with this category.
Over-filling is the most common aesthetic error and the hardest to see in your own mirror. Follow-up is worth attending both to confirm the desired effect and to catch anything unwanted early.
General information only, not medical advice. Individual anatomy and healing vary. See the disclaimer.