Once credited for St. Louis Cardinals slugger Mark McGwire's 70-homer season in 1998, creatine is now being blamed for the cramping issues that nearly derailed one NBA prospect's only season of college basketball.
As Kansas star and top NBA Draft hopeful Darryn Peterson told ESPN, the supplement aimed at increasing muscle mass left him in fear for his life after one September workout with Jayhawks coach Bill Self.
'I made it to the training room and just started begging them to call 911,' Peterson said. 'They were trying to get a vein to get me the IV, get me back hydrated. But I was cramping so hard they couldn't get a vein. I thought I was going to die on the training table that day.'
The cramping issues persisted throughout his freshman season in Lawrence, where Peterson's toughness and desire were questioned by fans and critics alike. As Peterson told ESPN's Ramona Shelburne, he'd never taken creatine before his freshman season. Now, after some postseason blood work, he believes his cramping issues were directly tied to the supplement.
Peterson was plagued by cramping issues throughout the 2025-26 season with Kansas. 'But after the season I took two weeks off and they did tests which showed my baseline level was already high,' he said. 'So, they said when I dosed [a process of increasing a dose over time to create maximum benefit at the beginning of taking a supplement], it must've made the levels unsafe.'
Even when Peterson wasn't cramping, fear of the issue began to impact his day-to-day life. 'Whenever I felt anything like that come on, my initial thought was that it might get to that again,' Peterson continued. 'And I can't let that happen and be embarrassed and have that on TV and all that. It kind of put me in a tizzy because I didn't know what was causing it. Nothing has ever been wrong with me before. Basketball is my life. What I love to do. But something was going on and I couldn't figure it out. My biggest thing was I'm going to keep trying because we don't know what's wrong and we can't say something's wrong. So, I'm going to go out there and when it happens, I'm going to ask to come out. I don't know if that was a right or wrong move.'
Peterson faced criticism for the cramping issues as some questioned his desire to play. Despite using IV bags, electrolyte supplements and undergoing frequent massages, Peterson still missed 11 games and was seen removing himself from a February matchup with rival Oklahoma State. Criticism soon followed, not that Peterson, his teammates or his support network could do anything about it.
His AAU coach, former NBA forward and coach Sam Mitchell, was particularly upset over the negativity. 'Excuse my language, but that mother***er worked his ass off,' Mitchell told ESPN. 'He loved this s***. Even to the point where I'd have to say, you got to get some rest. ... I got on in one game because he was trying to block every shot and the mother***er had eight blocks. You can do that here, but when you get to the league your team needs you to save your energy to make everyone else better. Not be jumping all over trying to block every shot.'
Mark McGwire credited his power to creatine in the late 1990s, but later said he'd used PEDs. Widely projected to be a top-four pick in next month's NBA Draft, Peterson should have a better idea of where he could be headed after Sunday's lottery. The 6ft 6in point combo guard averaged 20.2 points and 4.2 rebounds a game last season, while making an impressive 38.2 percent of his 3-point attempts and 82.6 percent of his free throws.
Creatine first gained popularity in the early 1990s and was quickly adopted in MLB clubhouses. The supplement was further buoyed when McGwire admitted to taking it along with the testosterone precursor androstenedione. According to McGwire, creatine helped him recover from his weightlifting routine. Later, in 2010, McGwire admitted to Bob Costas that he also used steroids on and off over a 10-year period.
