Cosmetics Formulation Development

1. I will be bothered to ask which one is used to see results and better performance between Stabilized Vitamin C (Natural-C Glycol™) Serum with Vitamin CE Ferulic (Lite) 2. If using Galactomyces Ferment Filtrate (ak a. Pitera ) must be applied before Vitamin C 3. Retinal serum should be used if If you use 1 and 3, thank you.

Hello. 1. Depends on skin type. If dry, recommend Vitamin CE Ferulic Normal skin recommended stabilized vitamin c 2. Should be applied at intervals because other products tend to cause Vitamin C deteriorates faster. Wait for it to be absorbed into the skin. 15-30 minutes ago and then apply other products or formulas as usual