Which vitamin ampoule would you recommend for skin whitening?

I have been suffering from adult acne for a while, so my skin has redness.

I have a lot left, so I'm thinking of using vitamin ampoules for my skincare routine.

A gentle product that is non-irritating and can be used as a first vitamin ampoule

Do you have any recommendations? My skin type is combination dry and oily.

I am feeling a bit sensitive.

I didn't have any major problems when I used retinol, so

I'm also planning to try using vitamins.