Up front, I need to admit that when I purchased this product, I thought it had SPF, so I was a bit disappointed when I realized my mistake; I already had a Vitamin C serum.
However, I recently upgraded my retinoid serum to tretinoin, which I use 2-3x/week. I found that, especially early on, my skin was too sensitive the morning after tret for my usual Vitamin C serum, which contains ascorbic acid — stronger and more researched/proven, but harsh! Instead, I started using this serum instead, which has a relatively high percentage of a good Vitamin C derivative (ethyl ascorbic acid), which is much gentler, and has promising research backing it. It also has a ton of centella, which is both incredibly soothing, and has been shown to increase the effectiveness of Vitamin C. Using this serum, which is creamy but light, helped my skin feel healthier and brighter.
So I definitely recommend this product, especially for those using other, harsher products and/or those with sensitive skin!