MODEL RELEASED. Anti-wrinkle injection. Man having an injection in his upper lip to remove skin wrinkles. This cosmetic surgery involves the introduction of hyaluronic acid that fills out and smooths the skin beneath the wrinkle. Wrinkles are due to the skin losing its elasticity and firmness as it ages. Hyaluronic acid is not derived from animal tissue and therefore poses less risk of allergic reactions often associated with other treatments. The process may need to be repeated every few years to maintain the wrinkle-free appearance.