With an estimated net worth of around $400 million, tech entrepreneur Bryan Johnson has access to the world’s best health care. But swapping blood with his 17-year-old son and 70-year-old father and undergoing daily body scans by a team of 30 doctors isn’t quite cutting it for the 46-year-old centi-millionaire who wants to be 18 again.

Now, the Blueprint founder is taking trips to the remote Caribbean island of Roatán to be injected with a genetically enhancing drug that’s not been approved by the FDA—and according to at least one scientist “will kill someone”.

At $25,000 a go, the gene therapy works by turbocharging the body’s production of follistatin—a protein that helps manage the production of other proteins and hormones—to reduce inflammation, increase muscle mass, and improve bone density. It is, according to Minicircle Inc, the small U.S. startup behind the therapy, one of humanity’s best hopes for “extreme longevity”.

The company opted not to charge Johnson for the follistatin therapy—but apparently, their treatment is a bargain.

“Most gene therapies cost more than $1 million a pop,” Walter Patterson, Minicircle’s co-founder and chief scientific officer, told Bloomberg. “This therapy is made so that anyone in the world can have access to it.”

Minicircle has yet to publish clinical trial data for its follistatin therapy, which is the first in a series of products Minicircle plans to roll out. It’s why scientists are issuing stark warnings about the dangers of trying out unregulated gene therapies.

“These have no evidence for working, don’t make sense from a scientific perspective and likely will kill someone by inducing cancer or liver failure,” Christin Glorioso, a physician and neuroscientist, wrote about follistatin and other unregulated gene therapies in her longevity and health newsletter.

A former FDA official helped Johnson weigh up the risks

For Minicircle, the benefit of gaining endorsement from a longevity influencer like Johnson is clear. “He’s by far the most high-profile person to come down here,” Minicircle co-founder Mac Davis told Bloomberg. “Bryan is giving us something worth more than what we would charge him.” 

But why would Johnson forgo FDA approvals to become a human guinea pig for the startup? Certainly, saving money doesn’t come into it.

In reality, the youth-chasing executive and his main doctor, Oliver Zolman, had already created a list of around 20 radical treatments with supposed longevity benefits—and follistatin was one of them.

Their risk-benefit analysis included having their own team of scientists and a former FDA official shower the Minicircle team with questions. Evidently, the answers were good enough for Johnson to give the treatment a go and he received his first dosage on Sept. 10, according to his Instagram. 

“I am now a genetically enhanced human,” Johnson exclaimed, while pointing out the treatment’s benefits in mice. 

“Follistatin gene therapy ranks 7th among lifespan studies, extending mouse lifespan by 30%,” he added.

Indeed, animal studies found that mice who were injected with follistatin had improved age-related loss of muscle and bone density. However, the benefits of follistatin have yet to be studied on healthy human participants.

For its medical trial, Minicircle selected 44 people aged 23 to 89 to be injected with the same dosage of follistatin and then tracked for three months. According to Minicircle—which has yet to publish the trial data—participants managed to shave off around 11 years from their genetic age. 

Johnson on the other hand has been open about how successful—or unsuccessful—various parts of his $2-million-a-year regime have been. Since launching Blueprint in 2021, with the aim of monitoring and reversing his biological age, he’s been published his progress on the company’s website for all to follow along.

Since becoming “genetically enhanced”, he’s reported a 160% spike in his body’s follistatin levels, according to Bloomberg. But he hasn’t yet set new personal records while working out—with the exception of finally being able to rip his shirt off just 14 days after the treatment.

Subscribe to the Eye on AI newsletter to stay abreast of how AI is shaping the future of business. Sign up for free.



Original: Fortune | FORTUNE: Bryan Johnson is being used as a human guinea pig in unproven tests to reprogram human genes in an island off Honduras