I have ordered the ProHealth Longevity NMN Pro Powder for a second time. After the first use (aprox 3 months) I didn't feel too much difference, but I thought it is working, because of feeling less tired at all. For now, I'm in the middle of the second pack and I know it is working well. I feel more energy, less stress, sleep better and as a bonus I'm loosing weight. I didn't change much in my daily routine, so I think it is due to the NMN. We are using it both me and my wife. To Czech Republic it takes about 10 days for delivery, I paid for the most cheap shipping, so the service is very good too.