The Food and Drug Administration issued a warning Wednesday to manufacturers of alcoholic energy drinks such as Four Loko about the dangers of added caffeine, but USC students say it’s the low price that makes these drinks so popular.The FDA warning said the combination of caffeine and alcohol is dangerous and told manufacturers they must take action to reduce risks to those consuming the drinks.“[Four Loko] is probably the most popular drink this semester,” said Charlie Scully, a senior majoring in business administration. “I’m not for it being banned, but I understand why.”A 23.5-ounce can of Four Loko typically sells for less than $3, and one can is equivalent to about four 12-ounce beers.Students such as Scully and Ari Jakobson, also a senior majoring in business administration, said most of their peers drink Four Loko because of its low price.“It’s definitely a popular drink among my friends, partly because it’s so low-priced for the amount of alcohol it contains,” Jakobson said. “I think the negative publicity surrounding it recently also gives it a positive effect for college students who are looking to be a little crazier and rebel a little bit.”“Drink one of those and you’re set for a while, and two of those you can go crazy,” Scully added. “People like that feeling.”Health experts say the combination of caffeine and alcohol often results in students becoming unaware of how drunk they are, because of the masking effect of caffeine.Four Loko contains 135 mg of caffeine in one can. When the caffeine wears off, drinkers feel the full effects of the alcohol.“Four Loko is dangerous because it causes students to get drunk without even knowing it, causing impaired judgment and health issues,” said Jennifer Unger, a USC professor of preventative medicine.Before the FDA warning, however, the maker of Four Loko, Phusion Projects Inc., already said it was removing the caffeine content from its drinks.Four Loko has become popular among college students around the nation for several months, but it entered the national spotlight when nine students from Central Washington University were taken to the hospital after consuming the drink.“It is likely that Four Loko is chugged, producing the effect of downing a half-pint of vodka,” said Steven Sussman, a professor at the Keck School of Medicine.Four states — Washington, Michigan, Utah and Oklahoma — have already banned alcoholic energy drinks, but federal regulators have not confirmed that a national ban is imminent.“Alcohol toxicity is a real issue here; students who down a can will get drunk unless they are heavy drinkers,” Sussman said. “What is needed is a large social climate change regarding what the rights of passage and entertainment in college might best be.”Keely Flanagan, a junior majoring in screenwriting, said the effects of Four Loko aren’t always pleasant.“When you finally sober up, you feel dizzy and really sick to your stomach. It’s like you’re hung over, but wired and wide awake so you can’t sleep it off,” she said. “I think it’s popular because of the mythology of it. It’s the drink of our generation — part energy drink, part alcohol. It’s like liquid nitrogen that won’t necessarily kill you.”Dara Weinraub and Suji Pyun contributed to this report.