Imagine you’re the leader of one of the most powerful nations in the world. You have everything you could want at your disposal: power, influence, money. But, the problem is, your time at the top is fleeting. I’m not talking about the prospect of a coup or a revolution, or even a democratic election: I’m talking about the thing even more certain in life than taxes. I’m talking about death.
In early September, China’s Xi Jinping and Russia’s Vladimir Putin were caught on mic talking about strategies to stay young. “With the development of biotechnology, human organs can be continuously transplanted, and people can live younger and younger, and even achieve immortality,” Putin said via an interpreter to Xi. “There’s a chance,” he continued, “of also living to 150 [years old].” But is this even possible, and what would it mean for the world if the people with power were able to live for ever?
Over the centuries, we have used ever more sophisticated technology to heal ourselves into unprecedented longevity. In the 20th century, it was innovations in public health and medicine that effected this transformation, allowing today’s children to live longer, healthier lives than at any time in history. Yet that’s still not enough for some.
I’ve been a technology reporter for 25 years, chronicling the rise of the web from its early days. I have reported on how it has transformed our social world, and I’ve railed against overzealous developers pushing disruptive innovations that inevitably come into conflict with society at large. I got curious about the growing cadre of billionaire investors coming from Silicon Valley who wanted to live for ever. What world were they imagining and building, and how would the rest of us fit into it? I’ve met people who have tried radical life-extending experiments and biohackers who swear the numbers will keep them for ever young, and seen inside Silicon Valley labs where technologists are planning a longevity revolution. I uncovered the motivations, ethical conundrums and doctrines that drive the belief that we are on the brink of eternal life, and that these immortalists are the people who will give it to us.
There are several different types of immortality in this movement. There’s the literal live-for-ever kind, dominated by highly intelligent, mathematically minded computer scientists, philosophers and hopefuls who have an unwavering faith in the life-giving power of technology. They imagine that they will one day merge with artificial intelligence and become post-human, and will live for ever in a state of bliss and delight.
Then there are the immortalists who want to reconstruct the infrastructure of the world we live in so that they can live for ever. Already, and in plain sight, they are restructuring sovereign nation states, pushing an agenda of technological acceleration at any cost. These powerful people aren’t searching for the fountain of youth – they’re building it.
And still another version of immortality is parroted by people like Xi and Putin, who believe in the certainty of exponentially accelerating science and technology. Life will continue not by merging with tech, but by using it to slow down the onslaught of time, thereby allowing medical science to develop treatments that will heal us. They believe they are living proof of age reversal, physical rejuvenation and the ability to stop time.
Imagine old age. What comes to mind? For many, it means losing faculties, and losing function. Ageing is something we all experience, at different rates and in different ways. In 2015, in the World Report on Ageing and Health, the World Health Organization defined healthy ageing as “the process of developing and maintaining the functional ability that maintains wellbeing in older age”. Key to this definition is functional ability, or “intrinsic capacity” – “the health-related attributes that enable people to be and to do what they have reason to value”.
That’s because what you want to do when you’re 80 is not what you want to do when you’re 20, nor do you necessarily want to do the same things that someone else does. Say you want to go skydiving at 80, but can’t get on the plane because it’s become more difficult to get upstairs, your functional ability has declined. If you’re 80 and you have no physical trouble getting on the plane, but you have cataracts and you’d rather read than parachute, your functional ability has also declined. So it’s not just the presence, relative encroachment or absence of a disease, or even the absolute number of years of life that’s important, but the quality and the quantity of those years in the context of a range of other factors, such as lifestyle.
The term used for this in age research is “healthspan” – and the objective in most contemporary science in this field is to increase it. Healthspan means staying healthy for longer, and keeping the diseases of old age at bay. It means keeping your body young, intervening in the process of growing old, and considering the possibility of “rejuvenation”.
This is where “respectable” science gasps: “the fringe of the fringe”, a doctor colleague said to me dismissively when I mentioned I was researching the topic. Yet there is a growing body of evidence that there is something biological underlying how we age – and some out-there researchers, funded by Silicon Valley, are trying to figure out how to tweak it, so that our bodies actually can go backwards in time.
It started in the 1990s, when a young molecular biologist named Cynthia Kenyon and her postgrad student Ramon Tabtiang designed several landmark experiments with a tiny nematode called C. elegans. Their findings suggested that tweaking a gene doubled the lifespans of these creatures.
Kenyon gave a talk at Stanford University not long afterwards. “She looked like a super-young, very hip professor,” says Irina Conboy, who was there with her then boyfriend Mike, both PhD students at the time. “And she suggested that simply by changing the intensity of certain molecules, you can make an old animal younger.”
When I meet Irina and Mike Conboy in their office – now married, they are both professors in the bioengineering department at the University of California, Berkeley – they are wearing matching tie-dye sweatshirts, and finishing each other’s sentences. They are charming, warm and a bit shambolic. Their tiny white pup is comfortably chewing on his leg on a saggy sofa, next to a sheaf of papers.
The couple have one big question when it comes to ageing: “So why is it that all the tissues of the body seem to grow old together?” Mike asks. “It doesn’t matter whether they’re on the outside or on the inside, whether they’re exercised or going along for the ride. Everything seems to go to heck in a handbasket with age.” They wondered if there was some kind of signal in the body that changes the molecular structure of muscles, and ages them all simultaneously. They set out to find out what all tissues have in common.
Think back to your biology class in school, and you might remember those hand-drawn anatomy posters with elaborate illustrations and labels for each part of the body: the skeletal system – the body’s framework of bones, ligaments, cartilage and joints that gives us structure and shape; the nervous system – the network that transmits electrical signals between our brain and the rest of our body; and the vascular system – the blood-vessel pipelines that take nutrients and oxygen to our muscles. Could it be that some sort of ageing alarm was passed through the body via one of these systems?
“The ideal experiment would be, ‘OK, what if we transplanted a young nervous system into an old mouse,’” says Mike. “Well, we can’t technically do that. What if we put a young vascular system in an old mouse? We can’t do that, either.”
Irina looks at me with a twinkle in her eye while Mike continues. “What if we put young blood into an old mouse?” he says. This would have to be more than a one-off injection – they would need to transfer a large proportion of blood from a young mouse to an old one to make sure there was an observable effect.
“What if we connected the young and old mouse together? You can take an old mouse and stitch it to a young mouse, and instead of the skin healing edge to edge of the old mouse, it heals across edge to edge to the young mouse,” Mike explains, describing a technique known as parabiosis. “As that tissue heals, blood vessels re-form there. Now you have blood slowly trickling from one animal to the other and back and forth.”
Between 2003 and 2004, they sutured three categories of mice together: young and old, young and young, and old and old. They let the blood flow for five weeks, and then gave each mouse an injury in its hind leg muscle. Five days later, the mice with the young blood – including the old ones – recovered “robustly”, unlike the untampered-with oldies, whose muscles regenerated “typical of aged animals”.
The team tried again elsewhere, with injuries on other body parts. The liver, same thing. The brain, same thing. As the results began to trickle in over the lifespan of their conjoined rodents, the Conboys were able to conclusively say that the tissues of the old mice looked more like the tissues of a young mouse – whether they were in the muscles or in the liver or in the brain. Something in the young blood rejuvenated the old tissues. In 2005, they published their results in Nature.
The Conboys had discovered a fountain of youth, but they had no idea why or how it worked.
Scientific knowledge is more of a process than a single moment in time. The path to today is littered with old, disproven ideas that, perhaps, were actually the stepping stones that got us to where we are now. The road to longevity is no different.
In 1889, in Paris, Charles-Édouard Brown-Séquard, a distinguished and celebrated physiologist and member of the Royal Society, stood before an esteemed audience of peers at the Société de Biologie and gave what became his most famous presentation. Sensing himself growing old at the age of 72, Brown-Séquard had started investigating loss of sexual function, and claimed to have found the right treatment: an injection into both of his arms of a mixture of blood taken from the gonads, semen and “juice extracted from a testicle” of a dog or a guinea pig.
He was met with stunned silence. There had been research suggesting that something as yet unidentified in the sex organs was a salve for the effects of age (at least in men). After his treatment, Brown-Séquard reported improved energy levels, muscle rejuvenation, cognitive functioning, and heightened abilities and skills in the bedroom. Alas, it proved to be a potent form of placebo effect.
However, one of Brown-Séquard’s apprentices was Serge “Samuel” Voronoff, also a student under the eugenicist Alexis Carrel, a Nobel laureate and pioneer of organ transplantation. Voronoff took his mentors’ two novel ideas – putting an organ from one body into another, and the mysterious rejuvenating power of testicles – and tested his own theory of rejuvenation: he transplanted sex glands from the young into the old. Specifically, he transplanted fragments of monkey testicles into older men’s scrotums. In 1923, he appeared before scientists at the International Congress of Surgeons in London, informing them that the procedure had been so successful that the Pasteur Institute had built him a chimpanzee-breeding compound in west Africa.
Within two decades, more than 45 surgeons around the world used his technique more than 2,000 times; 500 men were operated on in France alone. Voronoff published books and papers, and was quoted as saying that life could span more than 140 years; the press described the outcomes as miraculous and life-changing. In Brazil, where he was a minor celebrity, Voronoff inspired carnival songs. But his celebrity faded when his methods were proven to be less effective than what appeared to be the enigmatic active agent: testosterone, isolated by Ernst Laqueur in 1935.
Both men, learned and respectable, had pulled on a thread of scientific research that seemed logical. Yet both were off the mark. At the time, the gold standard of regulatory checks hadn’t yet been established to ensure that the treatment they were proposing was both safe and effective. Today, the equivalent treatments have been, and young blood is dancing around it.
In 2016, Jesse Karmazin, a Stanford Medical School graduate, opened Ambrosia Health’s doors in a business park near a redwood forest in Monterey, California, to run an experiment testing the Conboys’ hypothesis, but in humans. There still wasn’t much to go on about why young blood appeared to reverse ageing – in the decade of research since their papers on parabiosis, only a few molecular and hormonal candidates had surfaced, but even in these the evidence for them was inconclusive, and all of it was in mice.
Karmazin decided to run a human trial of his own as a private company, and charged an entry fee to anyone over the age of 35 who wanted to take part: $8,000 to have biomarkers measured, to receive a transfusion of one litre of young plasma from a donor between the ages of 16 and 25, and to have their biomarkers measured again for comparison.
He phoned Irina Conboy to see what she thought; she declined involvement. She didn’t agree with the premise, she tells me – Karmazin’s study didn’t “fit very well”. There wasn’t enough evidence that positive effects would be reflected so broadly. Yet, even without her endorsement, the company and the trial got more than 100 press mentions in under two years.
Jesselyn Cook was a tech reporter at the Huffington Post at the time. “Karmazin was quoted saying things like, ‘It works, it reverses ageing’, and ‘I’m not really in the camp of saying this will provide immortality, but I think it comes pretty close,’” she says. “It doesn’t matter if you were young, wanting to feel extra capable, or if you were old and trying to, in his own words, reverse your age,” Cook tells me. “It just seemed like no matter what the problem was, Ambrosia could help.”
By 2019, Ambrosia Health had a total of five clinics around the US, and Karmazin was hinting he was looking to open another in Manhattan. Other private clinics, also claiming to carry out research studies, had popped up, offering paying clients young blood transfusions. Yet young plasma treatments for the physical and cognitive effects of age had never been approved by the FDA, which released a statement in February that year citing concerns that patients were being “preyed upon” by “unscrupulous actors” touting the treatments as “cures and remedies”. Ambrosia Health went dark within hours.
When I exchanged emails with Karmazin in 2023, he told me: “The FDA never reviewed our data before making their announcement … I have no idea if they were ever aware of Ambrosia, in fact. It is entirely possible they were referring to our competitors, who acted with less diligence and respect for the rules.”
“If you think that you can simply go and do the procedure and become younger – not yet,” Irina Conboy says to me when I bring up the Ambrosia Health story. “If the goal is to stop ageing and plateau, or start to gradually become younger, I would just say that, right now, we don’t have it. But if you invest correctly, your time and efforts and resources, we will have it soon. That is my feeling about it. Soon.”
“Soon” is exactly what some longevity pioneers are banking on.
When I spoke with “rejuvenation athlete” Bryan Johnson in 2023, he was 45 years old. The biohacker and tech entrepreneur had used his Blueprint algorithm to help him “reverse” time, by devising a strict protocol of supplements, nutrition, and exercise that would bring his “biological” age significantly lower than his “chronological” age. He had also dabbled in young plasma therapy; his teenage son Talmadge had become what Johnson called his “blood boy” for a short time while Johnson’s medical team assessed whether there was any truth to the rumours of blood’s benefits. Johnson ultimately discontinued the treatment with his son, but still tweets about going to the clinic every few months to pick up several litres of albumin – the protein in plasma – like a regular longevity oil change.
On Johnson’s 46th birthday, he tested his biological age again. His objective over the previous 12 months of the protocol was to see if Blueprint could help him stay the same biological age for a whole year. His computer appeared to be doing its job: his body was ageing at a rate of 277 days for every 365.
Now, holding back time for one year may not seem enough to live for ever, but here’s why it might: think of it like a rocket leaving the Earth. It needs to reach a certain speed to overcome the pull of gravity. This is called escape velocity. Now imagine that through treatments, lifestyle changes and prayers you could stop yourself from ageing. The idea is that you would eventually reach the point where each age-related disease, such as dementia or diabetes, and those that we don’t know about yet, will have been cured before your body ages into them. You would escape the pull of mortality. This is called longevity escape velocity. Fundamentally, this isn’t living for ever; it’s not dying today.
The escape velocity cusp is closer than most of us would imagine, maintains gerontologist Dr Aubrey de Grey, who coined the term in 2004 and now runs private research group the LEV Foundation. Two decades ago, he predicted that, as we are already so long-lived, “even a 30% increase in healthy life span will give the first beneficiaries of rejuvenation therapies another 20 years – an eternity in science – to benefit from second-generation therapies that would give another 30%, and so on ad infinitum”.
Longevity escape velocity relies on a major mathematical assumption: that technology can keep up with the heterogeneity of human decline. The conditions that affect you when you’re young are – medically speaking – relatively simple. But the illnesses of old age could be said to grow in severity at an exponential rate. Johnson has to stay young, or an age-related disease that can’t yet be treated will kill him. If you are trying to age in reverse, you would need to be living in a time when treatments and technologies both improve at the same exponential rate. These people are literally racing against the clock.
They believe in an idea called Moore’s law – a widely held observation that predicts that every 18 months, computer technology gets twice as good. Moore’s law is the reason the phone that you have in your hand costs around the same as the last model (not taking into account inflation), but is twice as powerful.
Everything from MRI scans to drug discovery to protein folding is now being regarded as a computational problem, therefore the idea goes that modern medicine, too, should be characterised by an exponential increase of capability. If every 18 months it gets twice as powerful at keeping you alive, what will medicine be like in 20 years’ time? And if you figure out how not to age in that time, you begin to understand why living to 200 years seems like something that could happen.
Technofundamentalists believe that ever advancing technology should be able to solve the ever more complex problems we throw at it. So if the body can be expressed as data and we can figure out how to fix it when it goes wrong, why aren’t we already living for ever? Life – mortality – is complicated.
In his 2024 book Why We Die, Nobel laureate Venki Ramakrishnan describes “the characteristic arrogance that many physicists and computer scientists display toward biologists” that causes the engineers to miss something crucial. That something may by physical, but it’s more likely to be something impossible to break down into data. Seamus O’Mahony, the doctor and prize-winning author of The Way We Die Now, found this when he went to a longevity conference in 2025. “They are interested only in the biomolecular and the monetisable,” he says. “I heard a great deal over the four days about AI-designed drugs, glycans, the transcriptome ageing clock, but almost nothing on the complexity of death systems and the social determinants of death and dying. They seemed strangely uncurious about the enemy they have declared war on. Ageing to them is simply a technical problem that can, and will, be fixed.”
The irony is that the mechanistic metaphor that served us so well is now dramatically impeding further progress. Too much faith in data and engineering overlooks the value of the unknown and the unknowable. In order to defeat ageing and death, we must bend to the technical tools that are supposed to serve us – from spreadsheets to large language models. We must become more like appliances. “This impulse, this motivation, this moral mandate to want to improve yourself means we must become like a machine,” says Dr Elke Schwarz, political theorist at Queen Mary University of London.
Yet “we live an inconvenient life”, says Schwartz. “We are weird. We are messy. Our bodies are mortal. We die. Why can’t we be like products? Why can’t we be like the things that computer scientists make that they can improve and fine-tune?” Because we aren’t. Yet this is the starting point for how Silicon Valley intends to “fix” mortality, and their simple solutions – and what they need to achieve them – are on the radar of some of the most powerful people in the world.
In 2025, Donald Trump returned to the Oval Office with bold ambitions to rework the US government. Flanking him at his inauguration were representatives of the largest tech companies in the world, all of whom have thrown their weight and their Silicon Valley wealth behind America’s AI future.
In the months since January 2025, Trump has granted them access to finances and infrastructure that will ensure that AI is the driving force behind the US economy; it will also propel the technological search for eternal life. They believe it is a moral imperative to use technology to enhance the body and mind towards immortality.
Regulation is standing in their way, and regulation is what Trump’s team is dismantling. In the early part of 2025, Elon Musk’s Doge implemented actions that significantly affected research at the National Institutes of Health (NIH), and regulatory oversight of the FDA. The department cancelled leases, reduced the workforce in the FDA’s Office of Digital Transformation, and terminated hundreds of research projects valued at billions of dollars.
Techno-libertarian Peter Thiel, longevity investor and co-founder of PayPal, has assisted with the placement of former colleagues and staffers in positions where they can help dissolve government oversight. The acting director of the Centers for Disease Control and Prevention – until recently RFK Jr’s right hand man – is Jim O’Neill, a longtime Thiel ally who in 2014 suggested reforms to the FDA “so that it’s approving drugs after their sponsors have demonstrated safety – and let people start using them, at their own risk, but not much risk of safety”, which might include unproven longevity treatments using “young blood”.
The cost of giving so much to the technofundamentalist dream of AI immortality has been that resources have been allocated away from initiatives that support people who are getting older today. The administration proposed cuts of hundreds of billions of dollars to Medicare – the social support network for healthcare for millions of US citizens over the age of 65 – and cancelled the White House Conference on Ageing, a flagship event held every 10 years since 1961 to determine the strategic direction for policy to support older Americans.
Truly, all of this radical technological and governance innovation will not help the rest of us live longer, healthier lives.
It’s easy to roll our eyes at people like Xi and Putin who wish for immortality, and to dismiss their delusions of grandeur. They believe we are on the brink of radically extended life, and that they, uniquely in history, are the ones who will help build the machines that will get us there.
But consider this: the technologists who fundamentally believe in the immortality project – whether they want to literally live for ever, or are building AI that they think will usher in the next enlightenment – are enjoying unparalleled political access to the leaders of the world, and they are once again building our future.
For the immortalists of Silicon Valley and the rich and the powerful like Xi and Putin, death is not considered an inevitability. Although organ transplantation for eternal life is science fiction, they do have a head start in the race to longevity escape velocity, simply because they can afford cutting-edge treatments, personalised protocols, and as much young blood as they can morally handle. They can live on: as kingmakers, rulers of the world, or bits of computer code that carry their essence throughout the cosmos. But as they remodel the world in their image, they promote the myth that human beings are only as complex as computer code. These are the ideas that are laying the groundwork for an eternal for ever. But we do have a choice about whether to accept them – or to live in the here and now.
