Procedure: Plump up creased, furrowed, or sunken facial skin; add fullness to lips and backs of hands. Works best on thin, dry, light-colored skin.

Length: 15 minutes to I hour per session.

Anesthesia: Collagen: usually none; local may be included with the injection. Fat: local. In/Outpatient: Outpatient.

Side Effects: Temporary stinging, throbbing, or burn- ing sensation. Faint redness, swelling, excess fullness.

Risks: Collagen: allergic reactions including rash, hives, swelling, or flu-like symptoms; possible triggering of connective-tissue or autoimmune diseases. Both: Contour irregularities; infection.

Duration of Results: Variable; a few months to I year.