Biohacker Bryan Johnson revealed shocking images of an allergic reaction he had to an ‘age defying’ treatment that involved injecting another person’s fat into his face.

The 47-year-old multimillionaire, who is known for his outlandish anti-ageing treatments, sought the jabs as part of his quest for a ‘baby face’.

But the procedure went disasterously wrong, resulting in extreme swelling of his upper face that caused him to temporarily lose his vision.

Sharing the experience with his 953,000 Instagram followers, the entrepreneur said the unfortunate reaction kicked in 30 minutes after the treatment.

‘Immediately following the injections, my face began to blow up. And then it got worse, and worse, and worse until I couldn’t even see.

‘It was a severe allergic reaction.’

He added that he called a colleague who he was scheduled to meet and warned: ‘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?’

Mr Johnson is no stranger to elaborate and risky wellness stunts.

Last year Mr Johnson enlisted his teenage son and his father for a tri-generational blood swapping treatment in an attempt to ‘youthify’ their bodies.

The procedure saw Johnson and son, Talmage, have a litre of blood drained.

Talmage’s plasma was fed into Johnson’s veins, while Mr Johnson’s plasma was injected into Richard. He theorises that the infusion of ‘young blood’ can repair age-related damage to cells, reducing one’s biological age.

The biohacker has also claimed that he takes a hundred daily supplements, eats 70 pounds of pureed vegetables a month and has had more than 33,000 images taken of the inside of his bowels.

His latest procedure involved extracting fat cells from parts of the body like the thighs and abdomen, and injecting them into the less voluminous face to stimulate and restore volume in the skin.

However, Mr Johnson explained that he did not have enough fat on his own body, forcing him to use a donor.

He puts his slim physique down to a strict daily calorie consumption of 1,950 (roughly 500 less than the number recommended by the NHS).

This, he said, has drastically reduced his body fat — including on his face.

However Mr Johnson admitted to his Instagram followers that the eating plan made him ‘look gaunt’.

‘People thought I was on the brink of death,’ he said.

‘Facial fat, we discovered, is pretty important for how people perceive youth.

‘It didn’t matter how good my biomarkers were if I didn’t have face fat.’

Although the procedure didn’t go to plan, there was no lasting damage, Mr Johnson said.

‘Seven days later my face was back to normal and we were back in the trenches reformulating plans for our next attempt.’

The California-based biohacker, who made $800 million after selling his company Braintree, has spent million of dollars attempting to reverse his physical age.

He claims he now has the heart of a 37-year-old, the skin of a 28-year-old, and the fitness of an 18-year-old after adopting the highly-regimented program in 2020.

The tech mogul has also previously spoken about his skincare routine, admitting that he tries to minimise the time he spends in the sun by only venturing out  in the early mornings or in the evenings when the UV index is low.