I started using NADH 2 weeks ago and can honestly say, I have seen a remarkable improvement in my energy levels, since suffering from chronic fatigue for several years. I have extra energy to accomplish more tasks, I no longer have a foggy head, I am more alert, my nervous system seems much calmer and I am much more relaxed. I have tried numerous products for an improved level of energy, but nothing has given instant results as NADH. In fact nothing has ever made a noticeable difference. For my it has been a God Send and I highly recommend it to anyone requiring a greater level of energy. It is quite expensive but well worth the money.