Hey thuycha91 😊
Thanks for your question✨
I do not recommend using The Inkey List Azelaic Acid and Medik8 Retinal in the same routine, as both are active ingredients and can cause irritation together.
A good setup is to use azelaic acid in the morning (with sunscreen!) and retinal in the evening, or on completely different evenings. This way, the skin gets the best possible effect – without being overloaded.
Always wait and see how your skin reacts, preferably via a patch test first.
Hope the answer can be helpful and that you have a super nice day🌞