Appearing on Today Extra on Wednesday morning, the astrophysicist and artificial intelligence scientist took part in the World’s Greatest Shave to raise awareness and funds for the Leukaemia Foundation.

He first flaunted the long-haired look in early 2021 and gained a lot of attention on social media as his luscious brown locks and facial hair continued to grow.

Now, the 34-year-old is now completely bald as he received a zero shave on the Nine Network program.

But his hair will either be turned into a wig for those who have lost their hair during cancer treatment or transformed into compost and floating booms to help the environment by absorbing oil spills at sea.

It was only a few days ago that he had his hair cut shorter to allow for the shave and went back to looking the way he was remembered when he first hit Australian TV screens about three years ago.

While on the Today Extra, Dr Agnew joked about co-host Sylvia Jeffreys not cutting him as she shaved his head.

“There’s no nicks, no blood spilling or anything like that,” he said.

Dr Agnew told NCA NewsWire that he knew two people who had been affected by blood cancers and seeing them battle the disease and the affect it had on their friends and families was “hard to watch”.

“It’s just an overwhelming feeling of helplessness,” he said.

“It’s (cancer) agnostic in how and who it affects and it has a ripple effect on the person and their loved ones.

“This was an opportunity (for me) to be able to raise awareness and funds and bring a positive moment to those who are doing it tough.”

The scientist said having short hair was more manageable but he didn’t entirely rule out participating in the charity event in future.

“It was obviously a nerve-racking and daunting experience but it’s also a sobering one,” he said.

“It will grow out for a bit but will it be the Thor, Jesus, Tarzan look? That’s to be determined.”

More women are aware of blood cancers despite more men being diagnosed and losing their life to them.

Four in five Australians say they aren't confident of identifying blood cancer symptoms.

All money raised through the World’s Greatest Shave goes towards supporting families affected by blood cancer and to accelerate blood cancer research.

The Leukaemia Foundation has a goal of achieving zero lives lost to blood cancer by 2035.

So far, Dr Agnew has raised more than $9400 and aims to reach $30,000.

With donations still open, you can visit the website, click donate and search “Dr Matt Agnew” to contribute.

Dr Agnew starred in the 2019 season of Network Ten’s reality matchmaking show and chose chemical engineer Chelsie McLeod as his winner.

The couple’s relationship didn’t last long as they announced their split about two months after the finale aired.