What the hell is a B12 shot anyway? Well, it's a mega-dose of vitamin B -- administered by a needle. Charlize Theron and Hugh Jackman swear by them too. Prince reportedly gets a B12 fix before each performance. FYI: B12 has been called the "morning-after shot" because it helps alleviate a hangover; boozing depletes vitamin B from our bodies. When the Rage got a B12 shot last summer, she felt dizzy at first and then nothing. "B12, B.S.," she muttered as she drove away from Cedars with a sore forearm. Thirty minutes later, she felt a slight buzz -- akin to that first glass of white wine at a summer wedding -- and had some extra energy for the rest of the afternoon. To get a B12 shot, see internist Dr. Sabena Toor at Cedars-Sinai Medical Center. She gives out about 30 or so shots a week to patients to "reduce stress and increase energy."