Zac Efron is committed to staying sober.

The 'High School Musical Star' - who completed a stint in rehab just under a year ago for alleged cocaine and alcohol abuse - has made major life changes to keep himself substance-free.

The 26-year-old actor has stopped attending Hollywood parties and prefers to spend his time looking over movie scripts, going to the gym and attending his 12-step meetings to help with his addiction.

An insider told People magazine: ''He cut most everyone out of his life who were part of the party scene,'' while another added: ''[He] is totally committed to being sober now.''

Although the sources allege that Zac still ''has temptations'', the teen heart throb was is high spirits at the SXSW festival last weekend where he admitted to feeling ''blessed'' in his career so far.

He said: ''I've been blessed to have the opportunities I've had. It couldn't have happened better. I'm stoked.''

The 'That Awkward Moment' star also admitted that he's never felt better and is in a ''great place'' after conquering his demons in rehab.

He previously said: ''I'm so happy. I feel like I'm in a great place and I'm glad that I'm really here to share this moment with everybody and be present for all of it.

''It was an interesting year. I learned so many things. So much. The best part of it was being able to reflect upon that experience and realise how much I have learned about myself and the kind of man I want to be.''