He says it lets him know that it is working

Solid product and I've grown to trust Amazon's suppliers over the years as it has been consistent and competitively priced

So not what I expected our am used to with this product

Would not buy my pre-workout from anywhere else! Love the Margarita flavor! My husband LOVES C4! He goes to the gym daily and C4 gives him just the right amount of pick me up so he is motivated to keep going and to completely finish his work out

Don't take too much, don't take too little, and don't take it too often

The product came packed down and crusted, I have used this product for over a year and have never received it like this