Who: Madonna, Justin Timberlake, Charlize Theron and Britney Spears
What: The queen of pop is also a fan of this energy-boosting celeb fave, having regular shots of the re-energising B12 to help stay on top of her game. And she's not alone. Pal Justin Timberlake is also a fan, as is Charlize Theron, Britney Spears (pictured), Lindsay Lohan, Prince, and the list goes on. In fact, Madge (pictured) was the one who introduced JT to the latest Hollywood health fad. JT has since said the day the Material Girl gave him his first shot was the best day of his life!
Dozens of other celebs are also convinced that the B12 jab gives them an instant boost. Britney has reportedly demanded "emergency" jabs before going on stage and Tara Palmer-Tomkinson has also admitted to having regular jabs, saying she get "vitamin injections every two months or so".
So the celebs love it, but what do the health experts think? Well, it gets a big thumbs up from Elisa Zied, author of Feed Your Family Right!, who says that while we are all naturally supplied with the right amount of B12, having a little extra has no proven down sides.
Known as the "energy vitamin", all of the B vitamins (including thiamine, riboflavin, pyridoxine, folic acid and cyanocabalamin) are vital to an energetic, long life. Unfortunately, these sought-after vitamins are also easily flushed out of the body, and those on weight-loss diets, people who take antibiotics and alcoholics are more prone to deficiencies.