Will hyperpigmentation after fraxel laser (for stretch marks) go away?

I am not sure if you had treatment with 1550nm, 1927nm or both (Fraxel Dual). Fraxel 1550nm almost never causes PIH especially if you avoid any sun on the treated area until the skin color is back to normal.  1927nm is a little more likely to cause PIH, especially if you get any sun on the skin when it is still red.   Check back with a dermatologist for recommendations. 

Hello and thank you for your post. Your PIH (post inflammatory hyperpigmentation) will slowly overtime decrease. I certainly think it's important that you check with your board certified physician who performed your procedure to ensure that you have the most appropriate skin care directed to allow your skin to heal. Re-starting your retin-A would be helpful, and you may want to consider gentle skin moisturizers with alpha-hydroxyl acids, lactic acid, glycolic acids in small concentrations that will promote your skin exfoliation over time. Remember to wear broad spectrum sun block to protect the investment of your laser resurfacing procedure.