The mutagenic potential of tretinoin was evaluated in the Ames assay and from the in vivo mouse micronucleus assay, each of which were being negative. Tretinoin evens skin pigmentation by dispersing melanin granules 5. Melanin is often a pure pigment that contributes to pores and skin, hair, and eye color. https://en.paperblog.com/the-difference-between-retin-a-and-tretinoin-what-are-the-different-benefits-7139988/