Ashton Kutcher took medication in a bid to prevent going bald.

The 40-year-old actor - who has two children, Wyatt, three, and Dimitri, 14 months, with wife Mila Kunis - started worrying about losing his hair when he was just 25 years old, but quit the treatment five years ago and has now accepted his receding hairline.

He admitted: ''I've gone off of anything to retain my hair. I started getting very concerned when I was 25, and that's when I went on the Avodart. And I think like, five years ago I stopped and I did really good for a year, and now it's thinning out.''

And the former 'That 70s Show' star insisted he is ''comfortable'' with losing his locks now he is a married father.

Speaking to pal Dax Shepard on his new podcast 'Armchair Expert', he added: ''I've actually become comfortable with it. I'm just good with it. I've got kids now.''

And Dax - who has Lincoln, four, and Delta, three, with wife Kristen Bell - admitted he had also sought treatment to preserve his locks.

He said: ''I had heard that there was this doctor that would give you hair as thick as Brad Pitt's, and I was going to this guy and I was doing it for two years and I was like, 'What am I doing?' I think we both went to this doctor.''

Meanwhile, Ashton - who was previously married to Demi Moore - admitted he has never been a big drug user but did experiment with various illicit substances when he was in high school.

He said: ''When I was in high school and college, I smoked weed some and did mushrooms and tried acid and did some various things that were expansive for me at the time.

''So, I did a ton of that fun stuff when I was younger. And then when I went to college, I was like, 'I'm done.' I think that I smoked weed like one time when I was in college, and then after I dropped out and moved to Los Angeles.

''And so I didn't do drugs. I had entered into a pretty long run of sobriety from drugs, and I didn't really drink that much. If we went out during the weekends, I would drink, but I always kind of had a school night rule.

''If I had work the next day, I wasn't really going to. And I bent it a couple times here and there, but for the most part I really had a relatively sober living.''