This is one of my favorite and must have skin care products. I have used this (and sometimes the Skin Tx C-12 serum, which is also made by Vivierpharma) for years and my skin just loves it. I also used to work at a medspa where this was sold and our clients were all big fans. This has helped with brightening my skin, helping to reduce breakouts and helped my skin retain more moisture. I use this, the Vivierskin astringent, the Skin Tx Foaming gel cleanser, an eye cream (their Firming Eye Contour cream is good), and always use a sun block (Elta MD UV Sport or UV Clear). You should always use a sunblock to help prevent your skin from drying out and of course to prevent more damage. If you've never used the serum before, DON'T put the drops in your hands then on your face... you are wasting product! Drop the serum directly onto your skin (but don't touch the dropper to the skin) and rub in from there. Start from 4-6 drops and you can eventually work your way down to 3-4 as your skin tolerates it. You might have some irritation at first but it should go away. I love this product so much.