Which is more effective for skin whtening hydroquinone or kojic acid?

Hydroquinone is more effective with a prescription by a Dermatologist. Over the counter is usually 2% while prescriptions have 4% which is proven very effective. In essence, Hydroquinone is the only effective skin bleaching/fade system but temporary. It is so effective that prolonged usage can fade the skin to White. Use until the desired shade is obtained. Again, we are talking about your skin, seek a Dermatologist for skin counseling.