ORLANDO, Fla. -

We're used to seeing convenience store shelves lined with energy drinks which are loaded with sugar and caffeine.

Despite government warnings and a current Food and Drug Administration investigation into these drinks sales of caffeine-fueled beverages continue to soar.

But what if you could get the same jolt -- naturally?

New brands sold as "healthy" and "clean" are hitting store shelves, but are they safe?

It's a trend in energy drinks that has consumers like 52-year-old Joseph Cavalieri buzzing.

"I never drank any traditional energy drinks," said Cavalieri.

But he likes these because they promise a "cleaner" burst of energy.

"They're tasty and they sort of make you feel good, good on different levels," said Cavalieri.

"Consumers are savvy today, they read labels and, they know what the ingredients are in the products they ingest," explained beverage industry analyst Gary Hempill.

Among those ingredients: Green tea, organic cane sugar, herbs like guarana, B vitamins, and ginseng.

Hemphill said brands are responding to a growing thirst for healthy refreshment, and that's opening up the energy drink market to a whole new crowd.

"Up until now the real core energy drink consumer has tended to be younger, teen males. When you talk about health, it tends to be a concern or interest of, you know, somewhat older consumers," explained Hemphill.

"It's a very clever marketing strategy to advertise these drinks as clean, healthy alternatives, but there's really no evidence to support that," said Dr. Steven Meredith.

He said even though the caffeine boost comes from natural sources, "Caffeine is caffeine, whether it's synthesized in a lab, or whether it's synthesized in nature. It's still going to have the same pharmacological effects when you consume it."

In fact, many versions still pack a potent punch -- and that's put them on the FDA's radar, just like their more popular competitors.

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"There's really no scientific foundation, that I'm aware of, that suggests that when you consume one of these types of clean energy drinks, you should feel any differently than when you're consuming a traditional energy drink," said Meredith.

While Cavalieri will continue to fuel the clean energy market, he's cautious when craving a boost.

"I'm really sensitive to caffeine, so often I'll just drink half of the can," he said.

Doctors said if you choose to buy a "clean" energy drink, look for labels that clearly display the total amount of caffeine per serving.

Healthy adults should only have between three and four hundred milligrams a day.