I typically do not use energy shot products like this as they make me shaky, nervous and sometimes even make my heart race and affect my breathing. I was nervous before I tried this one so I split my shot up into two. Even after only drinking half I felt the increase in energy and alertness (I was having one of 'those day' at work and wasn't sure I would make it through the day) and felt great. I made it through the rest of my work day, my workout and a couple projects at home. I took half the shot at about 3:30 in the afternoon but had no trouble getting to sleep. I finished up the sample two days later and I swear it gave me the energy I needed to power through my back to back spin and body pump classes after a long week. I had tried the Strawberry Lemonade flavor and while I wasn't in love with the flavor its wasn't all that bad.