Here are ingredients that make energy drinks tick, plus performance claims from their websites and cans.
Claim: "GURU is an effective energy drink that naturally gets you going."
Ingredients: organic juices, guarana seed extract, echinacea flower extract, panax ginsent root extract, ginkgo biloba leaf extract
Claim: "Thanks to a unique combination of high quality ingredients Red Bull Energy Drink vitalizes body and mind."
Ingredients: caffeine, taurine, glucuronolactone, sucrose, and vitamins B3 (niacin), B5, B6 and B12.
ROCKSTAR ENERGY DRINK
Claim: "Enhanced with the potent herbal blend of guarana, ginkgo, ginseng and milk thistle, ROCKSTAR is scientifically formulated to provide an incredible energy boost for those who lead active and exhausting lifestyles -- from athletes to rock stars."
Ingredients: taurine, ginkgo biloba leaf extract, caffeine, L-Carnitine, inositol, Panax ginseng extract, and vitamins B2, B3, B5, B6 and B12.
STARBUCKS DOUBLESHOT ENERGY + COFFEE
Claim: "A powerful brew of espresso, B vitamins, guarana, ginseng and natural milk proteins."
Ingredients: Also includes vitamins D and C, Starbucks coffee and sugar.
Claim: "It's a wicked mega hit that delivers twice the buzz of a regular energy drink."
Ingredients: Includes an "energy blend" with caffeine, L-carnitine, guarana and glucose; plus taurine, Panax ginseng, and vitamins B6 and B12.
BAWLS GUARANA ROOT BEER
Claim: "The first ever Root Beer with added caffeine."
Ingredients: caffeine, guarana extract.
Claim: Guayusa contains the same amount of the world's most prized stimulant, caffeine.
Ingredients: guayusa tea
Ingredients: high-fructose corn syrup, caffeine, taurine, guarana, vitamins B6 and B12.
Claim: "Organic energy from the heart of the Amazon. We start with açaí and acerola along with rainforest botanicals like guaraná and yerba mate for an energy drink like no other."
Ingredients: (all listed are organic): cane syrup, acai and acerola juices, guarana extract, green tea extract, yerba mate extract.
PLAYBOY ENERGY DRINK
Claim: "9 out of 10 consumers prefer the taste of Playboy Energy Drink"
Ingredients: caffeine, taurine, Panax ginseng extract, guarana extract, L-carnitine, horny goat weed extract.
Claim: "At TrueToniqs, we find the world's most useful plants and compounds and use them in ways that improve people's lives."
Ingredients: eleuthero root extract (Siberian ginseng), rhodiola rosea root, choline, wild-crafted blue-green algae extract, DMAE (dimethylethanolamine), organic agave nectar.