I’m currently using Dr Dennis Gross HydraPure vitamin C serum. It’s an excellent product (pricey though, $95.00 although I’ve seen it cheaper online)

Check out Paula Begoin’s review on it, she rates it as a “best” vit C serum. This serum has 3 forms of vit C and I believe it’s 18% so a decent strength. This stuff feels incredibly silky going on, sinks in right away and most importantly delivers results! My 38 year old complexion is brighter, fine lines reduced and my skin looks and feels smooth! It’s definitely good stuff. Just thought I’d recommend it to you to try and see if you like it more them the Perricone. The Perricone is good but it’s really a “one note” product..it lacks any other significant stand out ingredients. The HydraPure boasts an impressive amount of vit C plus additional ingredients so more bang for your buck..or many bucks 😉