The Total Recall actor explained that he has embraced the "sweet simplicity" of life since embarking on an effective, if tedious, healthy living regime.
"One of the big things that I was drawn to about drugs was the ritual," he told Men's Health. "I don't put the same level of energy into healthy living as I did into unhealthy living.
"But I eat really well, drink loads of green tea, and take a s**t load of vitamins. It's so f**king boring... life has mutated to take on this sweet simplicity that I am really f**king okay with."
Farrell added that he is pleased to have been given a second shot in Hollywood thanks to his clean lifestyle.
"I had burned so many bridges in the film industry that I couldn't get a f**king meeting," he revealed. "But now I'm just enjoying life."
Farrell previously admitted to writing a break-up letter to his cigarettes when he gave up smoking.
Watch the trailer for Total Recall below: