Summer's approaching and I'll be applying sunscreen serveral times through out the day. I still got a couple of lightening ingredient at home. I wonder if it's a good idea to dissolve them and mix it with the sun screen, because that would mean a couple of additional apllication of lightening ingredients per day. I still got HQ powder but I'm not going to dissolve it in the sunscreen because your not supposed to have it on your skin while in the sun. However I still got Kojic Acid, Niacinamide, Glutathione, N-Acetyl-Cysteine and Vitamin C. I surely wouldn't mix the Vitamin C with the other substances but what do you think. Is it ok for the other substances to be on your skin while under sun exposure ?