Jul 11, 2015; Las Vegas, NV, USA; Chad Mendes (red gloves) is wobbled and ultimately knocked out by Conor McGregor (blue gloves) during their interim featherweight title bout during UFC 189 at MGM Grand Garden Arena. McGregor won via second round TKO. Mandatory Credit: Joe Camporeale-USA TODAY Sports

UFC President Dana White said on Joe Rogan’s podcast that Conor McGregor took stem cell injections in his knee in order to recover for his fight against Chad Mendes.

Most men don’t fight on a torn ACL, but most men aren’t UFC interim featherweight champion Conor McGregor.

Earlier this month, McGregor shared that he had torn 80 percent of his ACL, and was competing with the injury when he took to the cage against Chad Mendes at UFC 189. According to Emory Healthcare, it takes four to six months to possibly return to athletic competition, but UFC president Dana White said on the Joe Rogan Experience that the outspoken Irishmen took an unconventional approach to his recovery.

“He went out to Germany and got those (stem cells) shots,” White said.”He did some in L.A. too and that’s all he needed. He did that and he did his own physical therapy and he brought the knee right back.”

The use of stem cell injections has seen some promise from the scientific community but has yet to illicit any response considering it a better option to traditional ACL reconstruction. A 2014 article in the journal Arthroscopy and Sports Medicine says that despite success stories in animal models, there hasn’t been any concrete evidence presented that suggests stem cell injections will become standard.

“Despite the high hopes pinned on cell therapy approaches not only in ACL repair but in musculoskeletal regeneration in general, the use of stem cells is still far from reaching everyday clinical practice,” the authors wrote. “Besides regulatory obstacles, it still needs to be defined which cell type is most beneficial for regenerating injured ligament tissue.”

McGregor previously suffered a torn ACL in the aftermath of his fight against Max Holloway, so the Irish featherweight is no stranger to knee injuries. However, McGregor’s knee injuries could be something to watch as he moves forward in his career. As of now, McGregor seems to be in the clear, but things can change at the drop of a hat with a high-level athlete.