There's too much riding on his drug-taking program designed to make him the fastest swimmer ever.

"Me being the first athlete on board, we have to get this perfect," Magnussen told AAP.

"It's everyone's best interest for me, a, to swim fast, b, to prove that this process can be done safely and, c, to document that for everybody to see."

Magnussen understands all layers to being the pin-up for the Enhanced Games, a multi-sports event with no drug testing.

"James is unbelievably intelligent," Enhanced Games president Aron D'Souza told AAP.

"He is blessed on every level. He's 6'7, a 110kg giant. But he's an intellectual giant too."

Magnussen is the first athlete in the world to publicly commit to Melbourne-born D'Souza's Enhanced Games.

The 33-year-old, who quit competitive swimming in 2019, has been promised $1.5 million if he can break the 50m freestyle world record.

His best 50m free time is 21.52 seconds in 2013; the world record is Brazilian Cesar Cielo's 20.91 in a supersuit in 2009.

Magnussen is yet to start his drug-taking regime or know exactly what he'll be taking - to be decided when a date is set for the inaugural Games, slated for mid next year.

Then, he'll "reverse engineer" a year-long drugs program to peak and break the world record.

"I am pretty confident that if I nail everything, every aspect of my performance, that (record) is going to be achievable given the certain parameters I have got to work within that are obviously unique," he said.

"We're there for that world record."

The "certain parameters" are the drugs will be approved by the United States' Food and Drug Administration yet likely banned in sports.

"The fact that everything has to be FDA approved and prescribed by a doctor, actually gives me a lot of confidence in the process," Magnussen said.

"The initial opinion was that we'd be getting stuff out of the boot of a local gym junkie, but it's actually very medical, very scientific, and it's going to be done really safely."

Magnussen's journey will be centrepoint of a documentary made by Ridley Scott Associates and Rob McElhenney's More Better Productions.

"I love love, love those sporting documentaries ... Drive to Survive, Full Swing, Break Point, Sunderland 'Til I Die ... I love all that stuff," he said.

"I have watched so many of them from the outside and being one of the characters would be a privilege."

He expects more athletes to publicly commit to the Enhanced Games after this year's Olympics.

And he dismisses a list of critics including prime ministers, sports boffins, anti-doping chiefs, and the International and Australian Olympic committees.

"Standard," he said.

"Anyone that steps outside of the normal confines of society is going to get criticism."

Magnussen noted no discontent from his swimming cohort.

"I haven't had any backlash from swimmers, any swimmers I have spoken to have actually been super supportive," he said.

"It has been a generational divide on whether people support it or are a bit put off by it."

What hasn't put Magnussen off is the challenge - without drugs - of returning to elite swimming shape again.

"I don't believe you could just get a run-of-the-mill athlete, or get a college or high school athlete who is good, and give them performance enhancing drugs and get them to swim faster than the world record," he said.

"You need someone who is already at a really high level.

"I have been at that level before so it's just about getting back in the best shape I can before the whole project really starts in earnest."

Australian Associated Press