Hypopigmentation after TCA Peel. Can phototherapy help with repigmentation?

It is difficult to say for certain, but TCA, especially when applied in higher concentrations is well known for causing permanent loss of pigmentation. I personally have achieved gratifying results in repigmentation using professional microneedling accompanied by the application of pigment enhancing topical prescription medications, such as topical tyrosine and lanatoprost. Microneedling is believed to be able to autotransplant healthy melanocytes from the periphery around the depigmented areas into the hypopigmented regions, which may then be capable of responding to the addition of the pigment promoting medications. Make sure to consult with a board certified cosmetic dermatologist.