According to the 5 Hour Energy website, important vitamins in 5 Hour Energy include vitamins B-6, B-12, B-3 and B-9. It also contains citicoline, tyrosine, phenylalanine, taurine, malic acid, glucuronolactone and caffeine.
The 5 Hour Energy website claims that the B vitamins in the product perform functions like help convert carbohydrates into energy, help in the production of amino acids and help to maintain new cells. The website claims citicoline helps support brain function, tyrosine transmits nerve impulses to the brain, phenylalanine and caffeine enhance alertness, taurine processes minerals and helps cell membranes, and malic acid helps convert carbohydrates to energy. In addition, glucuronolactone is said to reduce sleepiness.
However, others believe only the caffeine provides energy. For example, CBS News published a report in 2014 about an Oregon lawsuit that stated 5 Hour Energy's claims about the non-caffeine ingredients giving people extra energy and alertness was misleading.