Is the melasma treatment effective on the similar-looking pigmentation on both cheeks?

Recently, when I look in the mirror, I see light brown spots in similar locations on both cheeks and cheekbones, not just on one side, so I am considering melasma treatment.

At first, I thought my skin tone was just dull, but it remains about the same over time, and it seems to look a bit darker on days when I've been exposed to a lot of UV rays. Since the boundaries aren't sharp like a mole but are spread out widely, I'm not even sure if home care can fix it.

Is melasma treatment effective even on this type?

I am also curious if the method of melasma treatment varies depending on the shape or location of the pigment.

I would also like to know if you can distinguish between melasma and simple blemishes before treatment. I am worried that receiving an incorrect procedure might cause it to darken, so I want to get an accurate diagnosis before starting.