I use NO test strips to confirm my levels and many other supplements that I am testing cannot even raise my levels a tiny bit. These give me a real strong response. They give a big boost to me before long bike rides and make the overall experience more beneficial. Perhaps this is only helpful to people who are NO deficient? Not sure... They are incredibly helpful to me in preparing for exercise.
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Update 1/2018: After getting used to these for many months the stickiness has never bothered me. I try not to let them get hot as that helps greatly. Also, I adapted to the taste and actually use it as a small treat similar to dark chocolate. I just let it dissolve in my mouth, then I wash it down with water afterward.
I have re-read some of the reviews on this and I think people are thinking of this as a Red Bull type of energy... I am not certain but I don't think that is what they are aiming for. For me it tends to open up the blood vessels and lets your body relax. My BP has been helped by these and they also remove anxiety for me before exercise events. (mostly bike for me) I think the energy it gives me is the ability to do exercise longer and more relaxed, not a caffeine hit.
If you are sitting at a desk and hoping this jacks you up the day, you may be looking at the wrong product. If you want to exercise longer or you want something to relax and possible help with stress or slight anxiety, this has worked well for me.