Here I am comment on behalf of my old father, Mr. Martin Lu. After 3 month plus consuming the NMN, 250mg, from Mac, at first, he found that his sleeping time becoming longer, sweet sleeping at night till the next morning, not like before, always awake because of the yawning sound by my brother. Even though now afternoon napping improves too. Also realize that his daily stamina becoming increase, not easily to get tired, very energetic, can carry out many house routine works. And one more wants to share is his recent blood test report, all indicators show good signs. May be is because of NMN. Anyway, my father feeling happy with this products and will continue to use it. Tqsm to THE YOUTH.