welcome to hcm
thanks for the query
facial pigmentation have many causes like pregnancy
,Hormonal contraceptives, Sun exposure
treatment response is generally slow
Discontinue hormonal contraception
if you are taking it
use a good sun screen .apply it before going out
use a good light moisturiser. if you have acne then avoid it .
Bleaching creams like Azelaic acid is helpful
creams containing alpha hydroxyacids including glycolic acid
and lactic acid peel off the pigment skin is also helpful
cream can give early results in addition to the above.
it may take sometime to reduce the pigmentation .so you have to keep patience