Numbuzin's signature anti- aging serum, No. 4 Collagen 73% Pudding Serum is formulated with 73% collagen, hydrolyzed elastin, and eight types of hyaluronic acid with varying molecular weights for firm, hydrated, and rejuvenated skin. Adenosine also helps maintain smoothness and suppleness. This serum provides deep, long-lasting hydration and instant rejuvenation. How To Use *When using new products, a patch test is recommended before use. Massage into skin after cleansing and toning.