Can you tell me what can energy drink do to you?

They are a scam: Most energy drinks are high doses of caffeine, which is a stimulant. If used occasionally they are not a big deal, and no worse than equivalent amounts of caffeine in soda or coffee. When used regularly and/or in high doses, caffeine increases anxiety, causes insomnia, can raise blood pressure and pulse, and causes a rebound fatigue. The vitamins etc some put in them are useless and add expense.