Johnson told Michael Rosenberg of Sports Illustrated in an interview released Friday that he used pot as a healing drug each week, but other pain-relief options were readily available for players.
"When I got to the league, [there] was opioid abuse," he said. "You really could go in the training room and get what you wanted. I can get Vicodin, I can get Oxy[contin]. It was too available. I used Percocet and stuff like that. And I did not like the way that made me feel. I had my preferred choice of medicine. Cannabis."
Johnson, who shocked the NFL world when he retired after just nine seasons in 2015, said there was a "very strong possibility" he would have played longer if the Lions were a contender.
"Not really," the six-time Pro Bowl selection responded when asked by Rosenberg whether it was a coincidence both he and Hall of Fame running back Barry Sanders retired at age 30 as members of the Lions.
Now 33, the Georgia Tech product said he suffered at least nine concussions during his time in Detroit. He also overcame countless other injuries en route to missing just nine of a possible 144 regular-season games, including one year in which he injured a foot, an ankle and both knees.
"Bam, hit the ground real hard. I'm seeing stars; I can't see straight," he told Rosenberg about his concussions. "But I know in a couple minutes I'm gonna be fine. Because I've done that plenty of times before."
Johnson now owns a cannabis company, Primitive, with former Lions teammate Rob Sims, and Locker Room Consulting, which is aimed at helping players with planning for their careers after football.
He's hopeful a call from the Hall of Fame will eventually come, but he doesn't think that will provide the final verdict about the impact he made in his prime, per Sports Illustrated.
"I was a beast during that time; I was hands down the best receiver in the game," he said. "I'm not gonna argue with you, but I know I was."
Johnson was named a first-team All-Pro three times during a career in which he racked up 731 receptions for 11,619 yards and 83 touchdowns in 135 games.