I did a lot of research on NMN before deciding on this product from Longevity Box. It ticked all the boxes. Fast delivery. No fuss. I knew that I would experience a rise in energy levels - which I am, however I was not expecting an increased libido to go with it. I noticed this within a week of taking the powdered supplement. I am so very happy with this product and will continue to make this part of my life for here on out.