Skin becomes loose and wrinkled when collagen and elastin are degraded. The skin's supply of elastin is damaged by sun exposure. To make sure you protect your skin from harmful UV rays, use a moisturizer with an SPF of 15 or higher every day. Remember to apply it to the neck as well as to the face. The skin on the neck is often looser and more delicate than the skin on the face.
Exfoliating products that contain either saliciylic acid or glycolic acid can help the skin build more collagen. For smoother, firmer skin, apply an exfoliant with one of these ingredients daily.
Retinol is a derivative of vitamin A that can improve the skin's remaining elastin; some studies even suggest that it can help the skin build new elastin. Use a retinol product, like the prescription cream Renova, once a day to improve the appearance of the skin.
If topical treatments do not achieve the desired results, consult a doctor about lasers, light therapies or cosmetic surgery.