Answer: Tretinoin cream is a common prescription given by dermatologists. Tretinoin is a vitamin A derivative. It works by two things: Firstly it increases the cell/skin turnover rate, and secondly, is boosts collagen synthesis.Because of these things it has many uses in dermatology.retinoin is a vitamin A derivative. It works by two things: Firstly it increases the cell/skin turnover rate, and secondly, is boosts collagen synthesis.