4/5
Hybrid N.O. was pretty good for a stim- free preworkout. I feel it is also very important to cycle off of caffeine for the sake of your adrenal glands. Going off of caffeine at the start of this product, I felt that it was very effective as I never got the usual headaches when going off. I feel that I never got headaches because of the blood-flow boosting capability of this product. Great for workouts, but of course after this bottle I went back to a stim based product, and for me there is no comparison.