I want to know the effects of niacin.

I have skin with a lot of blemishes and tan easily, so I am always worried.

I prefer cosmetics that are good for whitening, and I bought this because I heard that niacin is good for whitening.

I would like to know how much I need to use to see results.

I'm not sure if it can be used both in the morning and evening, but I feel like it wouldn't be good to use it during the day, so I only use it at night.

Has anyone used this and seen results?

Please also let me know how to use it~~