GPO can be used sa face that i am sure but as what you said mga sis use it correctly.
@geishamom: as you said di mo nawarn ang mom mo so maybe she put on too much and used cotton / cotton balls instead of just using her fingertips and just applying 1-2 drops and then massage it sa face. also, gpo is not recomended for those who have melasma / brown spots as this is not the cure / prevention for said skin disorder.
as for BCP: yes it is near mcdo.
as for those who are asking if the one in cubao are is the same i do not know because i only go to their dapitan store which is actually their only official store in manila (so far) except syempre yung mga diana stalder clinics but what they sell there are "diana stalder" products not "BCP".
i am not for GPO i am just telling my experience and so far it works for me. well... what may work for me maybe a disaster to someone d ba...

ohh, i forgot to answer about dun na itim itim thing. when you decide to try gpo sa face your skin wont turn black / red. it will just have a minor peeling for around 3-5 days. but no "sunog effect" pero kaw mag peel.