I didnt really want the caffeine and other stimulants of a normal preworkout supplement, but i wanted to experience a good pump and have the vasodialation effects of a nitric oxide product. I was a little on edge about getting a nitric oxide pill because i havent had barely any success with others, but i was supprised when i tried HemaNOvol. The first 2 days were so-so in terms of pumps, but the 3rd day was incredible. Wednesday happens to be my arm day, and my arms looked significantly larger than before. I didnt get that painful pump that some users talked about (which, in a way, i was looking foward to getting) but it was probably the best pump i got from any product in the past. Overall, it is great product that a lot of people should try if they have the money