Celebrities who have been to rehab

This week's revelations that young actor Zac Efron completed a pair of stays in rehab five months ago, allegedly for addiction to cocaine and Molly (MDMA), may have shocked some, while other stars who have sought treatment (sometimes more than once) seemed less surprising, based on their actions in public or their willingness to open up about their experience post-recovery. Here are some celebrities whose time in rehab is (one can only hope) behind them.

  • Zac Efron, best known for roles in "Hairspray" and "High School Musical," allegedly checked into rehab in March 2013 and again a month later to combat cocaine and Molly (MDMA) abuse. Stephen Lovekin/Getty Images

  • Lindsay Lohan's promising career was repeatedly derailed by issues with drugs and alcohol, problems on and off movie sets and jail time. In August 2013, the actress sat down for a post-rehab interview with Oprah Winfey. Dimitrios Kambouris/Getty Images

  • Gerard Butler has publicly acknowledged his battle with alcoholism and in 2012 completed a stint in rehab for an addiction to prescription pain killers. Rob Kim/Getty Images

  • In 1998, Charlie Sheen entered rehab following a cocaine overdose. A decade later, the "Two and a Half Men" star made several attempts at rehab, but was ultimately dimissed from the series. Mark Davis/Getty Images

  • Eric Dane, also known as "McSteamy" for his role on "Grey's Anatomy," checked into rehab in 2011 for prescription drug dependency. Angela Weiss/Getty Images

  • In 2004, Kelly Osbourne was in rehab to battle an addiction to painkillers. She relapsed over a year later, then again in 2009. Michael Kovac/Getty Images for BeautyCon

  • A heroin addiction led Steven Tyler to seek treatment in a rehab facility in 1986. He returned to rehab in 2009 to deal with pain management following multiple injuries after fallng off stage. Kevin Winter/Getty Images

  • Kirsten Dunst entered a Utah rehab facility in 2008. Fellow actress Eva Mendes also sought treatment at the same center. Jason Merritt/Getty Images

  • Britney Spears entered a rehab center for a single day in 2007, but after her infamous head-shaving incident she sought treatment again that same year. In 2008, she was involuntarily commited to a psychiatric facility. Jason Merritt/Getty Images

  • Country star Keith Urban was a frequent cocaine abuser and first checked into a rehab facility in 1998. In 2006, shortly after marrying actress Nicole Kidman, he entered rehab again, checking into the Betty Ford Clinic. Frazer Harrison/Getty Images