100mg of caffeine in clean energy form is really all you need to know. The other ingredients…who knows what the effect is and who cares?! With Pure Energy I've got the power and fuel to accomplish a block of tasks without stopping. Best of all, if you need more, because 100mg caffeine can only get you so far, you can take more. There's not really any noticeable side effect physically or mentally. Lastly, this is something to stock up on when Swansons has a sale, because it works even better when it costs less than other caffeine supplements! lol