There was a NT member who tried stem cell therapy a few years ago but did not have any improvement.

Where did you read about NFL players getting stem cell therapy for concussions ? Stem cell therapy is common for joint injuries.

I see plenty of stem cell companies that offer fat stem cell therapy for concussions but I don't see any research that confirms its effectiveness. I do see reports of NFL players who use it in hopes that it reduces the risks of CTE.

There is research into how to enhance the brain's own regenerative stem cell mechanism that slows as we age. This company appears to be working on such a process. Vitro Biopharma Advances Stem Cell Activation Therapy for Concussion - Vitro Biopharma

If you have seen any articles that report of the effectiveness of a stem cell therapy for concussions, plenty of people would be interested here. Posting a link would be great.