Which is better for skin whitening: kojic acid and L-glutathione, or hydroquinone, tretinoin and mometasone?

Skin lightening can be improved with different combination creams. Treatments vary from one individual to another depending on the skin type. Both of those options are a great approach, so try to only commit to one and stay consistent for a good amount of time to see which one appeals to your skin the best. The most important thing is to use sunblock with at least SPF 30 that has titanium or zinc oxide, and re-apply every 2 hours if out in the sun. To better assess your specific needs, consult a Dermatologist in your area.