The reason lies in the sebum membrane of the skin, which does not belong to the cell structure of the human body. It is present on the surface of our skin and protects our skin and plays an important barrier role.
It has a pH between 4 to 6, and it is actually very fragile. When you use a strong base or a strong acid on your skin, it can cause various skin problems after a while.
Therefore, if you want to maintain your skin well all the time, the products you use cannot be anyhow mixed or used. You must choose something suitable for your skin!
If you are smart, you should know by now what to take note.