Is there a treatment for melasma that already exists?

The sunlight was so strong this summer that I went out quite a bit without using a parasol or applying sunscreen, even though I have acne. As a result, I developed a lot of melasma all over my face due to the intense sun. I know prevention is important for melasma, but is there any way to reduce the ones that have already formed? My skin is normal and not very oily. I bought expensive lotions and creams from the market that claim to reduce melasma, but I didn't see any significant results after using them for about a month. It doesn't seem like the melasma disappears just by washing my face properly either. If I start applying sunscreen and getting professional treatments now, would it be possible to get rid of the melasma that has already appeared? I am curious.