Former heavyweight boxing champion Mike Tyson has admitted to using fentanyl during his career.

Axar.az reports that he said this on Katie Miller's podcast (an online broadcast).

"It was a painkiller, and I used it for my big toe. It was like heroin. When the effect wears off, as soon as the bandage is removed, you start to feel nausea and vomiting, just like when using heroin," Tyson said.

It should be noted that fentanyl is a powerful synthetic opioid. In the United States, it is allowed to be used as a painkiller in some cases, but it is prescribed only by a doctor because it can be fatal. Fentanyl is 100 times stronger than morphine and 50 times stronger than heroin.