- Dermatologically tested. How to use: Shake the bottle. Apply to clean and toned skin. Preferably during the night to optimize its use, since the skin is renewing itself during sleep. Spread a small amount of product on the forehead, cheeks and chin. Massage the product with circular and upward movements until completely absorbed. Apply BEFORE the moisturizing / nourishing cream. For best results, combine with a cream rich in Retinol. Proteoglycans combined with Postquam Professional Retinol cream. Active principles: Proteoglycans, vitamin C, hyaluronic acid and resveratrol obtained from grapes. Ingredients: Propylene Glycol, Ascorbic Acid, Aqua(Water), Glycosaminoglycans, Maltodextrin, Vitis Vinifera Fruit Extract, Benzoic Acid, Sodium Hyaluronate, Dehydroacetic Acid, Phenoxyethanol, Ethylhexylglycerin.