Source Naturals NADH 20mg Peppermint Lozenge - 30 Lozenges https://www.amazon.com/dp/B00185R8EC/ref=cm_sw_r_cp_api_i_bVaHCbBKQ8HAW this is the best/most effective NADH I’ve found. Other forms like pills aren’t absorbed properly so they don’t really work well. in studies they used 50mg, and found that was the best dose, but nobody sells sublingual 50mg. I noticed a difference even just taking 20mg but a biggest difference for me personally at 60mg, but it’s definitely expensive