Biohacker who spends $2 million a year to look '18 years old' reveals horrific side effect of one procedure

For many of us, fighting the aging process involves taking vitamins, lathering on anti-wrinkle cream, and donning collagen masks.

But for multi-millionaire Bryan Johnson, it's about investing $2 million dollars (about £1.6m) a year, and this included a recent procedure which saw other people's fat injected into his face.

It wasn't until just hours after he'd had the controversial, youth-defying technique done, however, that the business boss fell victim to one particularly stomach-wrenching side effect.

Unlike many millionaires, Johnson wasn't born into extreme wealth.

Aged just 20, the Utah-born entrepreneur developed a payment gateway which allows customers to pay online using credit cards, debit cards, PayPal, PayPal Credit, Apple Pay, Google Pay, and Venmo - also known as Braintree.

And after selling the company to PayPal in 2013 for a staggering $800 million (roughly £633m), he began focusing his fame and fortune on looking younger.

Now, at 47 years old, Johnson is considered a global biohacking front-runner, and regularly drops millions of dollars of tips and tricks which are allegedly aimed at creating a more youthful appearance as part of an organisation titled Project Blueprint.

He took to social media recently to reveal that he'd cut down his calorie consumption as a means of defying age, explaining that, though he was physically healthier, his face had become gaunt as a result.

This prompted him to keep his calorie count low, and begin 'injecting a fat-derived extracellular matrix' into his face 'to restore volume by stimulating my body’s natural fat growth'.

Johnson explained the initiative in recent tweet, revealing that he had to rely on a helping hand for the procedure to be successful.

"It’s possible to use one's own body fat for this," he explained.

"But the problem was I didn’t have enough fat on my body to extract, so I used a donor."

What he didn't expect to happen, however, was that the alien substance flowing around in his face would trigger a severe allergic reaction that would obscure his entire appearance.

"Immediately following the injections, my face began to blow up," he told his social media followers.

"And then it got worse, and worse, and worse until I couldn’t even see. It was a severe allergic reaction."

Not only did the swelling obstruct his vision, but it rendered him unrecognisable.

Johnson also had to warn his colleagues about the risk of him needing 'life-saving' treatment if he suddenly became unwell.

"Thirty minutes after the treatment, I was scheduled to meet with @ashleevance of Bloomberg to talk about Blueprint," he explained.

"I called him and said, 'Hey, so that you’re not alarmed, you may not recognize me today. I think I’m ok. I hope I’m ok. If I’m not ok, are you by chance trained to perform any life-saving actions?'"

Thankfully, however, the business mogul added that it took just a few days for the swelling to go down, and that he's looking forward to seeing the longer-term results of the procedure.