Boost Concentrate. Retinol has been shown in several clinical trials to combat common skin-ageing concerns such as facial wrinkles, lines, folds & a loss of firmness by stimulating collagen & hyaluronic acid production. Retinol has also been proven to improve skin clarity & texture, promote anti-pigmentation plus demonstrate anti-acne & pore-minimizing effects, all leading to a more youthful skin appearance. Retinol 40 is a concentrated booster serum containing 4.0% encapsulated all-trans retinol in its purest & most active over-the counter form. Retinol 40 is designed to incorporate with your usual night hydrator. Using the proprietory Medik 8 ' Retinol Ladder' system, it is possible to create an infinate number of concentrations of retinol from 0.1% upwards, with just one Retinol 40 bottle, leading to incredible economy & flexibility. Directions for use: To build up skin tolerance to retinol, allow 3 day intervals between applications for a minimum of two weeks. Consult with your GP before commencing a retinol regime if pregnant, lactating, undergoing skin peeling procedures or taking prescription medication for acne. Retinol 40 Boost Concentrate has been formulated to mix with your usual hydrator. In the evening add one drop of Retinol 40 Boost Concentrate to your usual hydrator before applying to your face. If using Retinol 40 Boost Concentrate in daylight, ensure that it is mixed with an SPF hydrator. Follow the doasge guide or the instructions of your skincare professional for alternative dosages. It is advised using Medik 8 Retinol following the guidance of professional therapists. [I] Ingredients: Simmondsia Chinensis Oil, Tocopherol Acetate, Retinol, Polysorbate 20, Cyclopentasiloxane, Cyclohexasiloxane, BHT, BH.[/I] Paraben & fragrance free.