I also use Hyaluronic acid and natural rose hip seed oil (normal retinol) in my serum and its amazing. The ultra fine l-ascorbic is so g=difficult to find locally. I received 90g for 27 USD (delivery and all) bit dear however it goes a good distance. Lauren, pH is a https://7figurebm.com/how-to-make-vitamin-c-serum-from-orange-peel/