US-based tech tycoon Bryan Johnson spends around $2 million each year to keep himself looking and feeling younger than he is.

Johnson, who is now 45 years old, became a millionaire after selling his tech company to PayPal for $800 million (£672.8 million) in 2013. He is now spending a chunk of that money on bio-hacking his body into regaining its youth.

He claims that he has the heart of a 37-year-old, the skin of a 28-year-old, and the lung capacity and fitness of an 18-year-old. Johnson has a team of 30 doctors and regenerative health experts who have carefully crafted a regimen that keeps his body younger than it actually is.

The millionaire told Bloomberg News that he aims to have the organs of an 18-year-old. He follows a strict vegan diet, exercises for an hour daily, and goes to bed every night at the same time.

"What I do may sound extreme, but I'm trying to prove that self-harm and decay are not inevitable," Johnson told the outlet.

He also has a machine that counts the number of nighttime erections. A team of experts comes up with new experiments based on scientific studies and tests them on Johnson.

He says that he suffered from depression and was nearly suicidal before he sold Braintree to PayPal, and that the decline in his mental and physical health is what led him to pursue eternal youth.

However, Johnson's quest has become a subject of ridicule on social media, with users slamming him for all this "nonsense."

"You could be like DiCaprio and make yourself feel younger by only dating women in their 20s, or you could be like Bryan Johnson and take 24 pills every morning, inject fat into your face, and blast your pelvis with electromagnetic pulses," wrote one user.

"This kinda 'reverse the aging process' nonsense is soooooo grating," wrote another. But Johnson does not seem to be one who keeps quiet when they are trolled on social media. He put out an entire Twitter thread addressing his "hater."

"Responses today were surprisingly tame. Haters, I know you are hard at work creating zingers, take-downs, and insults. I'm looking forward to them!" read one of his tweets.

Million dollar bet against aging
Representative image Reuters