"I smoked during fights. I just have to smoke, I'm sorry. I'm a smoker … I smoke every day. I never stopped smoking."
The former heavyweight champ said he stopped using cocaine almost three years ago but has continued smoking marijuana.
Both fighters were tested by the Voluntary Anti-Doping Association for performance enhancing drugs ahead of the fight, but cannabis is not a banned substance.
Recreational cannabis use has been legal in the state of California since late 2016.
"It's just who I am," Tyson added. "It has no effect on me from a negative standpoint.
"It's just what I do and how I am and how I'm going to die. There's no explanation. There's no beginning, there's no end ... it just numbs me. It doesn't numb the pain."
Tyson retired from professional boxing in 2005 after losing to Peter McBride, but has since put his focus behind his lucrative cannabis business called Tyson Hollistic, where it is believed he earns around £500,000-per-month (NZ$1 million).
He has long been an advocate for the medicinal benefits of cannabis and is open about his use of the drug.
In May 2019, he was among 150 current and former athletes who supported a petition to remove cannabis from the prohibited substances list under the World Anti-Doping Agency.
Tyson also said he would "absolutely" step back into the ring for another exhibition match, while giving some of the money he earned to charity.
"I could've done everything better," said Tyson.
"Everything I was doing I could've done it better, so God willing, I'll be better the next exhibition.
"I'm not here for my ego. My ego is taking the money, buying some planes, some nice houses, packing up a bunch of chicks and have some orgies and stuff.
"This is not who that is right now. That guy was just somebody that had to be, eventually he was a platform to become me."
