I was a bit skeptical when purchasing this at first because I've used vit C serums before with little to no effect, but this one is different. In the three months I've been using it my skin has become noticeably brighter and most of my old acne scars have faded. It has also greatly improved the texture of my skin, making it smoother and giving a glow. As with all vit C serums, you should only use this at night and definitely apply sunscreen during the day, since vitamin C is photosensitive. Keep the serum in a cool dark place to delay oxidation. I keep mine in the fridge and it lasts up to 6 months before it starts changing color, which is great for a vitamin C serum. Overall I would recommend this to anyone, it's effective, durable and cheap!