SAN DIEGO -- Energy drinks such as Red Bull, Monster and Amp can give you a powerful boost.

"A typical can of Red Bull which is about 8 ounces, has about as much caffeine as a cup of coffee," said UCSD toxicologist Dr. Richard Clark.

Energy beverages are a mixture of caffeine, taurine, vitamins and amino acids. But these drinks are not as healthy as you might think.

Clark said people with heart or blood pressure problems could get into trouble if they drink these or combine them with other caffeinated beverages such as colas or coffee.

"We don't know from can to can how much caffeine is in there," Clark said.

The unknown amount of caffeine inside these cans could increase tremors in people with neurological disorders.

"I would be careful about letting my kids drink this kind of stuff," said Clark.

Imagine what kind of impact it could have on a child. Clark said children have a heightened effect from the caffeine.

"Caffeine is definitely a drug and in some people it's not going to react well," Clark said.

Clark is also concered about combining energy drinks with alcohol. It's a popular drink choice at some trendy restaurants and bars in downtown San Diego.

The combination of caffeine and hard alcohol can have some negative health effects, which can prevent you from realizing how much alcohol you have consumed and falsely convince you that you are alert and capable of driving.

Energy drinks give an instant buzz, but you may want to question whether it's worth it.