Generally energy drinks include methylxanthines (including caffeine), B vitamins, and herbs. Other common ingredients are guarana (extracts from the guarana plant) or taurine plus various forms of ginseng, maltodextrin (a sweetening), inositol, carnitine, creatine, glucuronolactone and ginkgo biloba. Some contain high levels of sugar, while most brands also offer an artificially sweetened version. The central ingredient in most energy drinks is caffeine, the same stimulant found in coffee or tea, often in the form of guarana (as in Josta) or yerba mate. The average 237 milliliter (8 fluid ounce) energy drink has about 80 mg of caffeine, with 480 ml (16 fl. oz.) drinks containing around 150 mg, although more recently, drinks containing as much as 400 mg of caffeine (such as Burn) have been marketed.

Energy drinks may cause seizures in those who suffer from certain forms of epilepsy due to the "crash" following the energy high that occurs after consumption.^[1] France banned the popular energy drink Red Bull after the death of eighteen-year-old athlete Ross Cooney, who died after he played a basketball game after consuming four cans of the drink.^[2] The French Scientific Committee (J.D. Birkel) concluded that Red Bull has excessive amounts of caffeine.^[2] Denmark also banned Red Bull. Britain investigated the drink, but only issued a warning against its use by pregnant women.^[2]

Energy drinks raise many health concern, and several deaths have been linked to heavy energy drink consumption. ^[3]

Consumption of large amounts of caffeine can be hazardous. Energy drinks contain caffeine ranging from 80 to 360 mgs per drink. According to a recent study, an adult can consume up to 400 mgs per day without adverse health effects, while children and women of reproductive age should limit their consumption of caffeine to 300 mg per day. ^[4] This threshold can easily be reached by consuming multiple drinks within a day. Unhealthy doses of caffeine can lead to nervousness, irritability, anxiety, tremulousness, muscle twitching (hyperreflexia), insomnia, headaches and respiratory alkalosis. ^[5]

Energy drinks are often used as a mixer with alcohol, a popular combination being Red Bull with vodka. Combining energy drinks and alcohol can lead to several problems. Both alcohol and energy drinks dehydrate the body. Since dehydration is a contributor to hangovers, mixing these substances increases the likelihood of hangovers.^[6] Second, consumption of energy drinks obscures ones perception of fatigue from drinking, one indicator of excess alcohol consumption. Consequently, the mixing of substances can increase the amount of alcohol consumed.^[7]

Energy drinks may have come from Scotland in the form of Irn-Bru, first produced in the form of "Iron Brew" in 1901. In Japan, the energy drink dates at least as far back as the early 1960s, with the release of the Lipovitan. Most such products in Japan bear little resemblance to soft drinks, and are sold instead in small brown glass medicine bottles or cans styled to resemble such containers. These "genki drinks", which are also produced in South Korea, are marketed primarily to the salaryman set.

In UK, Lucozade Energy was originally introduced in 1929 as a hospital drink for "aiding the recovery;" in the early 1980s, it was promoted as an energy drink for "replenishing lost energy."

In 1994, The first European energy drink, Power Horse, was launched by Austrian company S. Spitz. it is still sold in many countries, even though it is perhaps overshadowed in most by its more famous Austrian rival, Red Bull.

In 1995, PepsiCo launched Josta, the first energy drink introduced by a major US beverage company.

In Europe, energy drinks were pioneered by the S. Spitz Company and a product named Power Horse, before the business savvy of Dietrich Mateschitz, an Austrian entrepreneur, ensured his Red Bull product became far better known, and a worldwide best seller. Mateschitz developed Red Bull based on the Thai drink Krating Daeng, itself based on Lipovitan. Red Bull was introduced to the US in 1997 and is the dominant brand there, with a market share of approximately 47%.^[8]

By the year 2001, the US energy drink market had grown to nearly 8 million per year in retail sales. Over the last 5 years, it grew an average of over 50% per year, totaling over $3 billion in 2005.^[9] Diet energy drinks are growing at nearly twice that rate within the category, as are 16-ounce sized energy drinks. It is estimated to hit nearly 4 billion in 2006, and both Goldman Sachs and Mintel predict that the energy drink market will hit $10 billion by 2010. Major companies' such as Pepsi, Coca-Cola, Molson, and Labatt have tried to match smaller companies' innovative and different approach, with marginal success.

Energy drinks are also popular as mixers.

These drinks are typically attractive to young people. Approximately 65% percent of its drinkers are younger than 35 years old, with males being approximately 65% of the market.^[9]

"Smart energy drinks" combine energy drinks with smart drinks.

In 2002 CCL Container and Mistic Brands, Inc., part of the Snapple Beverage Group, teamed up for the national launch of Mistic RĒ™. The result was a recyclable aluminum bottle. Since that introduction, many energy drinks are now packaged in the aluminum bottlecans produced by CCL.

Coca-Cola marketed two Powerade brand energy drinks in bullet-shaped, screw-top aluminum bottle cans. Capri Sun targeted 16-25 year-olds with its Island Refreshers line, graduating from a foil pouch design to a bottlecan.

• List of beverages containing guarana
• List of energy drinks