Try any of the ones Lindygirl or ally mentioned--also azelaic acid is a nice option (sold in US by prescription, or can order from Australia under brand name azclear) because (like retinol and BHA) it treats any acne you may have now, as well as lightening hyperpigmented spots from old acne.
Ally--why is arbutin controversial? I'm wondering because it's in one of the products I use (actually, what's in it is bearberry/uva ursi, which is a source of arbutin).
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