The phrase "herbal carbonated drink" makes us think of fizzy dirt tea, so when we saw it on the label for Rejuvenizer, we were reluctant to try it. The fact that the green tea/cranberry flavored Rejuvenizer is a dark purple color didn't help (we have a history of falling down with purple drinks). But we finally forced ourselves to take a sip, and surprisingly, it wasn't horrible.
But it didn't exactly taste great, either.
As for energy, there are plenty of ingredients in Rejuvenizer renowned for their peppy properties, including guarana (natural caffeine), kola nut, and taurine (also a main ingredient in Red Bull). The label doesn't list the amount of each, but the energy boost after drinking a 12 ounce bottle felt pretty decent. It wasn't a full throttle thrust like we get from espresso, but it was almost on par with a black tea.
In other words, drinking a Rejuvenizer may increase your alertness and activity for a solid hour or two, but it may twice as long to get the taste out of your mouth.