Julia Roberts had a "nice" time on magic mushrooms.

The 56-year-old actress - who has twins Hazel and Phinnaeus, 19, and Henry, 16, with husband Daniel Moder - revealed the "hardest" drug she's ever taken is the hallucinogen and though she had a pleasant experience, she wouldn't recommend other people follow her lead.

Playing 'Plead the Fifth' with Andy Cohen on 'Watch What Happens Live', she said in response to being asked the "hardest drug" she's tried: "Mushrooms."

Asked if it was a positive experience, she added: "Yeah, it was nice. I'm not gonna lie. Kids, don't try it at home."

The 'Leave the World Behind' actress was also asked who her "least favourite" star of 'Real Housewives' is.

She replied: "Oh. ...Um, I'm gonna say, who went to prison?."

After Andy confirmed it was 'Real Housewives of Salt Lake City' star Jen Shah - who was incarcerated for six years for defrauding elderly people in a telemarketing scheme - she added: "Yeah. I'm just saying that because she's in prison and I feel safe."

But one question Julia opted to "take the fifth" on and not answer was when she was asked to "rank these iconic films", before Andy had even given her the options.

He then told her it was 'Pretty Woman', 'My Best Friend's Wedding and 'Notting Hill'.

Explaining why she chose not to answer, Julia said: "See, I heard somebody in the audience go, 'Oh!' You don't want to do it."

Andy replied: "Right, because they're all so great. She pled the fifth. It's all good. Thank you for playing."

However, elsewhere on the show, Julia admitted she'd like to revisit her 1997 movie 'My Best Friend's Wedding'.

Asked which of her films she'd make a sequel to, she said: “I think maybe 'My Best Friend’s Wedding'.

“Because there are so many people in it and to see what they’re doing, and how Kimmy and Michael’s marriage is going.”