In a game of “Plead the Fifth” on “Watch What Happens Live” Thursday, host Andy Cohen asked the Oscar winner to name “the hardest drug you ever tried.”

Roberts answered “mushrooms,” saying the experience “was nice” while flashing her famous smile. “Not gonna lie,” she added.

The revelation puts the “Pretty Woman” star in some trippy celebrity company.

However, it’s still illegal in most of the U.S., and the Alcohol and Drug Foundation warns that “Use of any drug always carries some risk.”

Roberts has been promoting her new movie “Leave the World Behind” and recently commented on the death of her long-ago boyfriend, Matthew Perry.

“The sudden passing of anybody so young is heartbreaking,” the “Ticket to Paradise” actor said. “I think that you know, it just helps all of us just appreciate what we have and to keep going in a positive way as best we can.”