Medik8 Intelligent Retinol 3TR has a similar effect to Medik8 Retinol 3TR, but is slightly more powerful. It is perfect if you want to start with retinol. This serum contains 0.3% retinol (vitamin A). Retinol is converted into retinoic acid in the skin, a molecule that stimulates skin cells to produce proteins such as collagen. A higher level of retinoic acid improves and maintains collagen levels in the skin, for a fuller and more youthful skin. In addition, vitamin A stimulates the renewal of skin cells and prevents the production of too much melanin. Vitamin E is an antioxidant that protects the skin against free radicals. It also stabilizes vitamin A, for a powerful and long-lasting effect. The Time Release Technology gradually releases the intelligent formula during the night, to slow the absorption of vitamin A and reduce the chance of irritation. Medik8 Intelligent Retinol 3TR also contains climbazole and squalane. Climbazole stimulates the activity of retinol in the skin. It makes the serum more powerful, without causing irritation. Squalane helps restore the natural skin barrier and it hydrates effectively.