mandelic acid is a form of AHA that prevents or reduced photosensitivty which may be useful in dark skinned people doing lightening. our skin wants to return pigment that so vigerously especially when we are out in the sun. stuff like like exfoliators and peels,which help with lightening, also increases photosensitvity and can actually cause the skin to to darken very quickly if one doesnt keep up with maintainance.
mama is way too expensive though (especially if you want to use it over your entire body). you can try nucelle products. there is a serum or milk that contain 10% Mandelic acid. it could replace a 10% AHA peel.