Could retinal cause the hyperpigmentation on my lips and how long to would it take to resolve after stopping use? (Photos)

Hi, I've been using a oil containing Retin-A to my face almost nightly since early May. I love how my skin feels since. But now my lips have became hyperpigmented! That is the only change in my regimen. I already also use a product with azelaic acid and AHA too. Since stoping it's use around the lips the progression seems to have stopped. Question is will it remain?