Based on proven potency, the NR products manufactured by Renue By Science might be a reasonable choice.  On the other hand, Tru Niagen and Elysium are popular because of their associations with leading scientists in the field: Leonard Guarente at MIT and Charles Brenner at U of Iowa.    Consider proven potency vs. reputation: Renue by Science (formerly known as Alive By Science) states that it manufactures its NR products in...