Is it Islamically permissible to use creams and injections to lighten skin color from dark to white?

It is not permissible to use skin-lightening injections and creams merely out of a desire to change one's skin color, because this falls under seeking beauty and enhancement, which does not permit altering the skin's color. As for therapeutic purposes, such as removing acne and deformities, there is no harm in it. Ibn 'Uthaymeen, may Allah have mercy on him, differentiated between what is intended for beautification, which is impermissible if it is permanent, and what is intended for removing a blemish, which is permissible.