An American businessman who spends millions to try and reverse the effects of ageing has shared photos of what he looked like before.
Bryan Johnson invests around $2 million (£1.5 million) a year into his self-experimenting 'Project Blueprint' to try and turn back the clock on his biological age.
The venture capitalist from Utah became a very wealthy man after he sold his payment gateway company, Braintree Venmo, to PayPal for $800 million (£642 million) in 2013.
But since his health took a dip, Johnson has transitioned into a social media personality, and his attempts to reverse ageing have gone viral.
As I'm sure you're wondering, Johnson's efforts included fasting, a load of supplements, a strict workout routine and a plant-based diet.
Bryan Johnson spends £1.5 million a year to look like a teenager again (Instagram/@bryanjohnson_) The biohacker - who has three children from his first marriage - previously opened up about his past on his YouTube channel, saying that he started to put on some size after playing American football in high school.
At the age of 21, he then decided to spend two years in Ecuador when he was struck down by several illnesses and was unable to keep his food down.
Having then lost a 'ton of weight', he recalled: "[For] the first few months I was constantly throwing up.
Johnson looked very different in his 20s (Instagram/@bryanjohnson_) "I had diarrhea all the time I couldn't eat any food, my face broke out into to this rash slash acne - it was just awful."
"I was a missionary, and I lived among extreme poverty in Ecuador," he added to People.
"I felt really compelled to want to do something that would improve the world. I didn't know what.
"So the goal became to make a whole bunch of money by age 30, and then with that money, find something interesting to do."
He was unrecognisable (YouTube/Bryan Johnson) After selling Braintree in 2013, Johnson concluded that his lifestyle wasn't protecting him from ongoing health issues.
He said he felt overweight, stressed and depressed, realising that he wanted to pay closer attention to his habits.
Johnson founded Project Blueprint in 2021 and now spends ‘five hours every day’ going through his ‘longevity protocol’.
He claims his biomarkers now fall in the top percentiles and that his 'biological age' has dropped versus his chronological age, though experts caution that the science remains speculative.
"When I say that I've never been happier in my entire life, you can see where that's coming from," Johnson added.
"I sincerely mean it, I'm not trying to cover up, I'm not being dishonest."