The most common collagen used today is crossed linked hyaluronic acid, which is manufactured in the laboratory and not derived from the animals. This product is compatible with the body and does not generate any foreign body reaction. It is totally biodegradable and gets absorbed into the body after about a year, thus it is temporary. It is safe and does not have any longterm side effects. The filler comes in various grades of viscosity to suit different applications and locations.
The finer and less viscous filler is used for injection into the middle layer of the skin to smoothen wrinkles or lines. The most commonly used moderately viscous filler is injected into the deep layer of the skin to fill up deep permanent wrinkles or grooves like deep nasolabial groove, deep lines at the angle of the mouth (Marrionette lines), frown lines or forehead creases and vertical lines around the mouth. It may also be used below the skin in soft tissue spaces to augment soft tissue deficient areas like nasojugal groove (tear trough) and nasolabial groove. Lips that are too thin may be augmented using similar collagen injection to give more fullness to the vermillion and white roll with immediate result.
The procedure usually takes about 20-30 minutes as an office procedure. Usually no anaesthesia is required except for lip augmentation where a regional nerve block is used to reduce the pain in some patients. Cold compress is applied after the procedure to reduce the discomfort. For lip augmentation, it is likely the lip will be swollen over the next 24-48 hours due to fluid retention and body inflammatory response to the injection. Cold compress is advised during this period to help reduce the swelling.
Recently, another more viscous filler has been developed to give soft tissue volume enhancement over the face as well as enhancing the facial profile. It is commonly used to augment the flat anterior cheek and lateral cheek, lower lip, chin and jawline. This is a non-surgical alternative to fat grafting for soft tissue augmentation of the face, which has minimal downtime. The effect is temporary and last about 2 years. It can be repeated for maintenance and there is no known long-term side effect.