Yes the energy drinks you can buy over the counter can be harmful to you.
More and more people are dying from drinking too many energy drinks in a day. Just last month a young girl died after drinking just 2 in a 24 hour period. (The record herald)
I myself have never drunk nor do I plan on drinking an energy drink. I’ll stick to coffee.
Below are links to many stories on energy drink deaths.
Please use caution when consuming energy drinks.