Cryopreservation gets asked about a lot - by friends, family, and the occasional stranger at a dinner party who just found out what we do for a living. So we made this guide to be the one resource you can send anyone, whenever the topic comes up. Consider it the evergreen explainer: what cryopreservation actually is, why people choose it, what "dead" really means in this context, and how to sign up if you decide it's right for you.
What even is cryopreservation?
Cryopreservation - historically called cryonics, and increasingly referred to as biostasis or applied biostasis — is a stopgap measure. Not a cure, not a guarantee. A bridge that might get you into the future.
Right now, average life expectancy sits somewhere between 75 and 85, and a lucky few make it to 90. Almost no one reaches 100. History suggests that isn't changing quickly, no matter how loudly longevity gets discussed in the press. Medically, it is far easier to be healthy at 75, 80, or even 90 than it is to actually extend the human lifespan itself.
So the logic of cryopreservation is straightforward: live as healthily as possible, apply the longevity interventions that actually have evidence behind them, and when the doctors eventually tell you that you have weeks left to live - because at some point, for almost everyone, they will, cryopreservation becomes the option on the table.
Ideally, you've signed the paperwork years in advance. When the moment comes, our medical team is dispatched to you. Your doctors continue treating you exactly as they and you decide. But at the point of legal death, instead of cremation or burial, you are cryopreserved.
For most people who choose this path, the calculation is simple: cremation and burial are irreversible, full stop. Cryopreservation offers an unknown but real chance of something else. We can't tell you how long it will take, whether it will work, or at what probability. We can tell you the odds are better than zero.
Here's the part that matters most: cryopreservation is not freezing. Freezing causes ice crystals to form throughout the body's water content, and those crystals are structurally destructive to cells. Cryopreservation avoids that entirely through vitrification - cooling tissue into a glass-like, amorphous state, typically somewhere around -140°C to -196°C, with no ice crystal formation at all.
And this is the trick that makes the entire field work: at those temperatures, time effectively stops. It doesn't matter if you're preserved for 10 years or 200. Biological time, for all practical purposes, no longer passes. That buys the rest of us, society, medicine, science — as long as it takes to cure whatever was previously incurable, extend maximum lifespan, and eventually, reverse the preservation process itself.
None of that is promised. It's a chance, made available to people who understand exactly what they are and aren't signing up for.
A word on words: cryonics, biostasis, cryobiology, cryogenics
The vocabulary here is inconsistent, and it's worth untangling.
Cryonics is the historical term for human cryopreservation. Biostasis is the newer, broader term - combining "bio" and "stasis" to describe halting biological degradation, full stop. Applied biostasis specifically refers to using that concept on real people, in real end-of-life situations, rather than as a research topic.
The distinction that matters: cryonics is tightly associated with one method - dropping temperature using cryoprotective agents to reach a vitrified state. Biostasis is method-agnostic. It's an umbrella that could, in principle, include chemical fixation-based preservation approaches as well as vitrification.
That's part of why our company is named Tomorrow Biostasis, even though we operate as Tomorrow.bio. We want to stay open to whatever preservation technology proves best over time, rather than being locked to one method by our own name.
Two related terms worth knowing: cryobiology is the broader scientific field studying low temperature and biology - cells, organs, plant tissue, all of it. And cryogenics, common in some regions as a stand-in for human cryopreservation, is probably the most frequently misused term in the space. Cryogenics just refers to low temperatures generally; it isn't specific to preserving people at all.
If you want one rule of thumb: use biostasis, or applied biostasis when talking about humans specifically. Use human cryopreservation when you want to be precise about the low-temperature method.
A short history of human cryopreservation
The idea is old. Benjamin Franklin wrote about wanting to be preserved and revived in a future he couldn't otherwise see - centuries before anything resembling the technology existed.
The modern field began in the 1960s and 70s, built on the same core idea: instead of cremation or burial, preserve the body on the chance that future technology could reverse the process. But back then, it wasn't cryopreservation in the technical sense - it was simply freezing. No cryoprotective agents. Bodies were cooled directly to liquid nitrogen temperature, around -196°C, with no protection against ice crystal formation. The resulting cellular damage was significant, and the working assumption was that future technology might one day be advanced enough to repair even that.
Cryoprotective agents changed the picture, becoming standard practice around the 2000s. Early agents were simple single compounds like glycerol. Modern cryoprotective solutions combine multiple compounds - DMSO (dimethyl sulfoxide), ethylene glycol, sometimes formamide, and others - engineered together to vitrify tissue with minimal toxicity.
The next frontier in the field is making these agents better: less toxic, better glass-formers, capable of reaching higher tissue concentrations, with preservation quality verifiable through both CT scanning and electron microscopy.
Aren't these people just dead?
This is the question we get asked most, and it deserves a real answer - because "dead" is not the binary concept most people assume it to be.
In cryopreservation, it's useful to think about four distinct types of death:
Clinical death means the heart has stopped. Until the 1960s, this was considered final - irreversible, full stop. Then CPR was developed, and clinical death became recoverable within a window of roughly 6 to 10 minutes under normal conditions, and much longer under cold conditions. There's a saying in medicine: you're only dead if you're warm and dead. Cooling slows the cellular self-recycling processes that occur once oxygen runs out - the same processes cryopreservation aims to stop almost entirely. Anna Bågenholm, a Swedish doctor who fell into an icy river during a skiing accident, was revived roughly an hour after circulatory arrest with no lasting neurological damage, precisely because of that cooling effect.
Legal death is a jurisdiction-specific declaration, made by doctors once circulatory arrest is confirmed (with additional criteria in some countries). Cryopreservation can only begin after legal death is pronounced - our teams do not touch a patient beforehand, and the procedure only starts once all consent documentation is in place. This is also why cryopreservation isn't classified as a medical procedure: it's a donation, either to science or to future revival, depending on jurisdiction, precisely because we can put people into biostasis today but cannot yet bring them back.
Biological death describes a state where, based on current understanding, cellular degradation has progressed too far for even foreseeable future technology to reverse.
Information-theoretic death is the concept that matters most philosophically. Everything that makes you you - memory, personality, identity - is information encoded physically in the brain: cellular connections, their relative strengths, and the structures that maintain them. As long as that physical substrate remains intact enough, it is at least theoretically possible - not with today's technology, but perhaps with technology decades or centuries away - to recover it. Information-theoretic death is the point where that physical basis has degraded so completely that even in theory, nothing recoverable remains.
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Where exactly that line sits is genuinely debated within the field. What isn't debated is the goal: stay as far from that threshold as possible, so that whatever comes next has the best possible chance of working.
Why do people actually sign up?
Almost everyone who signs up with us falls into one or a combination of four categories of reasoning:
- I like life, and I want more of it.
- I would rather be alive tomorrow than not - and expect to feel the same way next year, next decade, and beyond.
- I'm curious about the future - what's technologically possible, how society evolves, what comes next.
- I don't like the idea of death - some people are simply, honestly, afraid of nonexistence.
Most members hold some blend of these. The demographic leans agnostic or atheist - people who see cremation or burial as final, with no further existence to speak of, and who would rather take a real if uncertain chance at something else. We do have religious members too; one memorably told us that more time on Earth simply meant more opportunity to do good, which is internally consistent with almost any belief system.
Framed simply: if you're diagnosed with a terminal illness tomorrow and given six weeks to live, and you haven't engaged with this topic beforehand, you will, in most Western countries, be either cremated or buried by default. Cryopreservation is not a competing option to some hypothetical better medical intervention - it's a choice between two real outcomes, each with real tradeoffs. It is genuinely expensive. There genuinely is no guarantee. But for people who've thought it through, it beats the alternative.
The overwhelming majority of our members - north of 99% — sign up with no current diagnosis at all. They're typically between 35 and 45, in good health, and have simply reasoned that if and when something happens, they'd rather have made the choice in advance than have it made for them by default.
Whatever you decide, the important thing is that it's a conscious decision - made deliberately, one way or the other, rather than left to happen by omission.
Who is Tomorrow.bio?
Tomorrow.bio exists to make cryopreservation better, more accessible, and more affordable.
Better means closing the gap between an average preservation and a theoretically ideal one - improving procedures until real-world quality reliably approaches what we can imagine as best-case.
More accessible means expanding where we operate. Before we existed, there was no serious cryopreservation organization in Europe at all - anyone interested had to work with a US-based provider from a distance. We now operate across Europe and the US, with plans to expand further.
More affordable means recognizing that cryopreservation should not be reserved for the wealthy. We're not there yet as a field, but reducing cost is one of our three core priorities, not an afterthought.
We're headquartered in Berlin, with medical teams and partner infrastructure across the US and Europe - covering everything from documentation and informed consent to on-site standby teams and long-term storage logistics, alongside applied R&D that turns research findings into day-to-day practice improvements.
For long-term storage, we deliberately do not do it ourselves. We collaborate with two Swiss foundations, because companies - however innovative - are not built for multi-century stability, and stability is exactly what long-term storage requires. The Patient Care Foundation becomes the legal guardian of anyone in biostasis, managing funds and ensuring their preservation wish is carried out indefinitely. The European Biostasis Foundation, a Swiss non-profit, funds research and provides the large-scale cryogenic storage infrastructure that the Patient Care Foundation relies on.
How to actually sign up
If you've read this far and you're leaning toward signing up, here's what that process looks like, and what it gets you.
Signing up has two components: membership and cryopreservation funding, each handled differently.
Membership starts at tomorrow.bio, where you sign the biostasis contract - the legal basis stating that upon death, you wish to donate your body for cryopreservation. Membership costs 50 euros a month, which keeps our medical teams trained and on standby, and includes access to our life extension program: guidance focused specifically on staying healthy enough, for long enough, that a future cryopreservation (should it ever be needed) goes as well as possible. This isn't a wellness or aesthetics program, it's about maintaining vascular health and cognitive function, because well-maintained vessels perfuse better with cryoprotective agent, and an intact brain is the entire point of the exercise.
We also offer means-tested pricing. If you're a student, between jobs, or going through a difficult financial period, tell us, we'll adjust the membership fee accordingly. The principle: cost should never be the reason someone doesn't sign up.
Funding covers the cryopreservation procedure and long-term storage itself: a one-time cost of €200,000 (or $220,000 USD) for whole-body preservation. This doesn't need to be paid upfront, it needs to be available at the time of death, typically arranged through life insurance (term, whole, or index-linked, depending on jurisdiction), with Tomorrow.bio named as beneficiary. Alternative funding structures, including payable-on-death accounts, are also available.
Finally, a last will and a patient advance directive round out the paperwork, ensuring your wishes are unambiguous even if family members disagree later, and that we receive the information we need directly from your doctors if you're unable to communicate it yourself.
If that all sounds right to you: reach out, sign up, put funding in place, and our team will walk you through everything else.
We're here to make sure you're still here, in 100 years, 200, or longer.
