Filler is largely hyaluronic acid gel. Hyaluronic acid is a complex sugar normally found in the skin, muscles, and tendons. There are other types of fillers.

It is injected using a needle a blunt cannula.

Hyaluronic acid can absorb up to 1,000 times its own weight in water, thereby adding new volume under the surface of sagging skin.

Fillers come with numbing medicines inside them. Most people tolerate it, but for some people and some areas, extra freezing with numbing creams may be needed. Occasionally, a numbing injection gives more comfort.

It is used by cosmetic physicians to soften deep folds and reduce wrinkles in the face, for example, smile lines. It is also used for lip augmentation. Another important use of it is for cheek and chin augmentation.

It gives volume and hydration to an ageing face and rejuvenates it.

All hyaluronic acid facial filler products are eventually absorbed by the body, usually within six to twelve months, requiring the patient to undergo repeat injections to maintain the younger look.

Expected side effects include: temporary redness, pain, tenderness during injection(s), swelling and/or bruising at the injection site. The more serious side effects include: infection, bumps and granulomas which are caused by a delayed immune reaction of the body to the fillers which is rare and can be bothersome to treat. Rare but the most important complication of filler injections is arterial/venous occlusion, which leads to ischemia, with subsequent necrosis of the skin and/or vision loss. It can be considered a dermatologic emergency and must be dealt with immediately.