I mixed the essence and used it now. It's 3.5 acid, so I'm going to find a base to use to adjust the PH, so I'd like some advice on which one is good. The price does not matter. I'm sorry it doesn't clog up the effect on the skin a little. I tried 1-2% AMP but I'm afraid it will cause phototoxic effect or not. because my face is very thin and I want to ask When should the base be mixed and how to mix it? Because there are some substances that need a stable PH value, such as
Vitamin B6 , GHK Cu, please advise from staff, thank you.