Medik8 has put its full Crystal Retinal serum range, strengths one through six, at 20% off during Amazon's Prime Big Deal Days, according to Who What Wear UK beauty editor Eleanor Vousden. The formula is built on retinaldehyde rather than standard retinol, along with hyaluronic acid, vitamin E and glycerin, and Medik8 says the retinaldehyde form works up to 11 times faster than retinol.
The brand markets the serum for acne, acne scarring, fine lines and wrinkles, pigmentation and uneven skin texture, with the varying strengths meant to let new retinoid users start low and work up as their skin adjusts. Vousden, who said she has used the serum for years at increasing strengths without irritation to her sensitive skin, recommends shoppers already using a given strength use the sale to stock up or step up to the next level.