Funny because at first I truley thought this was a suger pill, after seeing a couple of reviews i decided to experimented my pre workout off day cycles with & without using this product, after 3 days of not taking pre workout & not taking this product my body reacted good, but I had to work in more warm up sets & really squeeze to get the same effect & eventually I would get the same kick as before, while taking this product on my off days I i immediately noticed I didn’t have to work in any extra warm up sets, & would get the kick of my pre workout almost immediately, specifically the pump. As far as sleep, I didn’t notice much differences in that area but at the same I didn’t buy this for sleep. It works for me so I give it 5 stars.