Hi. Greetings. As you already mentioned yourself, the best way to reduce taning would be to use a sunscreen. However this is mainly protective in long term and most beneficial. To reduce your existing tan and pigmentation, you could consider using glycolic acid based creams, micro derm abrasion procedure, also chemical peels by a qualified dermatologist. Sunscreens like Face guard and photoban aquagel are fine if you want to try them