Everybody reacts differently to certain ingredients. Some people might notice sensitivity to two main ingredients – caffeine and Beta-Alanine.If you're feeling a bit jittery, restless, or experiencing a faster heartbeat after trying our pre-workout, it could be the caffeine giving you that extra kick. And if you're feeling tingles or itching, that's just the beta-alanine doing its thing. Don't worry, though! These effects are totally normal and usually pass within an hour. To ease into it, we suggest starting with a smaller serving size to see how your body responds.