Hi, welcome to My Channel and thank you so much for watching my video!! The formulation of this 2 products are completely different. Sunday Riley's CEO is formulated with 15% THD, an oil soluble Vitamin C while Dermaceutic uses 15% L' Ascorbic Acid, 14% Ascorbly Silanol and so forth to make up to 30%. The texture is also different, Sunday Riley is watery while the Dermaceutic is gel like. My personal opinion, having used both products, I will repurchase the Sunday Riley one. The watery texture gets absorbed straight into my skin (not just sitting on top). THD can travel into deeper fatty layers of skin as it is oil soluble. I got my results in fading the sun spots on my cheeks from Sunday Riley's. I hope this helps. I am more than happy to answer any questions as I do understand the frustrations of trying to fade those stubborn sun spots, etc. Please do subscribe to My Channel and share my videos to family/friends, I would really appreciate that as it encourages to make more videos like this. All the best with your skincare journey! Again, I love hearing from all the beautiful ladies that visit My Channel. Love from NZ! 💕

True super good magical ✨️ 😊