An energy drink is a beverage that contains ingredients to increase the drinker’s energy. They may or may not be carbonated. Most of the popular energy drinks contain ingredients such as caffeine, B vitamins, and various types of sugars while some may contain certain ingredients like taurine, glucuronolactone, guarana, ginseng, ginkgo biloba extract and L-carnitine. Caffeine stimulates neurons in the brain to keep us alert, releasing adrenaline, which sends a signal to the liver to pump more glucose into the bloodstream. With more glucose in the bloodstream and body, our brain is tricked into believing that we have more energy than we really do. Adrenaline makes heart beats faster and dilates the eyes. Energy drinks can cause some people to miss sleep since caffeine blocks the effects of adenosine, a brain chemical that helps us sleep and that can lead to insomnia, interfering with the ability to perform concentration heavy tasks. Consuming too much caffeine can produce a diuretic effect, which is also a cause of dehydration, anxiety, and irritability from too much of the stimulant. Also panic attacks and migraine headaches can occur from the caffeine withdrawal. Taurine, an amino acid, regulates skeletal muscle contraction and may reduce exercise-induced damage thus encouraging improved athletic performance. Also normal people who drink many energy drinks will have increased heart rates up to an hour later. People with certain heart problems can undergo cardiac arrest after having too many energy drinks. There is a study which shows the connection between energy drinks and cardiac problems. Another component, glucuronolactone claims to favor natural defense mechanism of the body but little research has been done and so it is still unknown whether this compound is effective. B vitamins, water-soluble vitamins, are required as coenzymes for proper cell functions. Because of the large amounts of sugar in these energy drinks, B vitamins are needed to transform those sugars into energy. Guarana is a tropical fruit rich in caffeine and it is used to increase energy. However, since guarana contains caffeine adding it will increase the overall amount of caffeine in the energy drinks. Ginseng, a popular herb, is also included in some energy drinks. Like guarana, the amount of ginseng in the energy drinks is not enough to cause a striking effect. Ginkgo biloba extract has been said to possess antioxidant properties. However, no detailed research has shown that it has important effects on healthy or ill persons. L-Carnitine, a compound made in the liver and kidneys, increases metabolism. It also increases oxygen consumption and decreases the respiratory quotient, increasing lipid metabolism and affects recovery from exercise stress. Sugars are the basic source of energy in the body, with glucose being the main carbohydrate that can easily be oxidized by the muscles for energy synthesis. However, long-term exposure of the body to excesses of sugars is associated with obesity and insulin resistance. Over time, cells will become unable to secrete sufficient amount of insulin to maintain normal blood glucose levels eventually the insulin-producing cells of the pancreas will be worn out, leading to type 2 diabetes. Heavily consuming these energy drinks may result in liver or nerve injury, various cardiovascular problems, seizures and ultimately death. While energy drinks may provide short and rapid effects, they are not actually good for our body in the long run.