The Will Smith movie Concussion showed the potential long-term effects of contact sports but former Brisbane Lion Justin Clarke can't watch it.

Retired Brisbane Lions defender Justin Clarke has avoided watching the Will Smith movie Concussion because he wants to get information about his condition from neurologists - not Hollywood.

Clarke, 22, was forced into retirement in March after he was heavily concussed during a practice match in January.

His injury was so severe that weeks after the incident, and despite scans and neurological tests showing no abnormality, he couldn't even remember the route to university, where he studies aeronautical science.

Clarke said he's familiar with the movie Concussion, which tells the story of the forensic pathologist who exposed the effects on NFL players who had suffered repeated blows to the head, but has no intention to watch.

"I'd rather get my information from scientists and not movies," Clarke told AAP.

"I've heard certain things from doctors over here that contradict certain things that were found in that movie, which is possibly a positive thing.

"I've heard it's good but it's a dramatisation and I'm probably holding back on watching it."

Clarke has become an ambassador for the University of Queensland's Brain Institute (QBI), which is undertaking a study on the effects of concussion on current athletes.

Other ambassadors include former Wallaby David Croft and NRL legend Steve Renouf.

Clarke offered all his scans to QBI to assist with helping to find better a treatment or remedy for concussion than just rest and recuperation.

"It's the least I can do really," he said.

"I was very passionate about footy and have always been, and part of playing footy is having knocks, so if we can be safer the way play footy with more research and more knowledge, that's the least I can do."

Besides being part of the program, Clarke says when the time comes he will also donate brain tissue to medical research.

He said life is returning to normal although he still has some memory issues.

"I do have some memory lapses in learning but I am on the track to returning to full health and memory function."

Croft and Renouf also say they will donate brain tissue to science.

The tests for chronic traumatic encephalopathy (CTE), which was highlighted by the US forensic pathologist, can only be diagnosed by tissue examination from a deceased person.