Lip pigmentation marks - what is the best treatment option? (photo)

Since 1,5 year I suffer from hyperpigmentation on my lower lip. Most likely this has been caused through lip biting in combination with full sun exposure (I know, very stupid..). One month ago I had a Pico laser session. However, I don't see any improvement. I know more laser sessions could be needed. However I am doubting if laser treatment would be best for this kind of pigmentation, what would you think? Perhaps better to treat it with a medical creme? Any suggestions?