FAQ: General Questions

Cryonics (from Greek kryos meaning icy cold) is the low-temperature preservation of humans who can no longer be sustained by today’s medicine, in the expectation they can be healed and resuscitated in the future using more advanced medical technologies. Cryopreservation of people is not reversible with current technology and is only practiced following pronouncement of legal death. The rationale for cryonics is that cryopreserved patients who do not meet the more stringent information-theoretic definition of death retain sufficient biological and neurological structure to be restored to full physical and mental health using advanced future technologies.

Rather than giving up on a patient and having them buried or cremated, cryonics preserves the person and gives them a chance to be treated by more advanced medicine in the future. Wouldn’t you take an experimental drug if it was your only chance? (See: Why cryonics makes sense) 

The practice of cryonics is justified by three facts: 

  1.  Many living things, including human embryos, can be successfully cryopreserved and revived. Cells and organisms do not need to operate continuously to remain alive. Humans can survive cardiac arrest and cessation of brain activity during hypothermia without lasting harm. Animals have survived three hours of cardiac arrest near 0°C (+32°F) (Cryobiology 23, 483-494 (1986)). There is no technical reason based on the laws of physics why such states of being could not be extended indefinitely at even lower temperatures. 
  2. Existing cryopreservation techniques, while not yet reversible, can preserve the fine structure of the brain remarkably well. This is especially true for cryopreservation by vitrification. Survival of structure, not function, determines survival of the organism. 
  3. It is now possible to foresee specific future technologies (see “A Cryopreservation Revival Scenario using Molecular Nanotechnology“) that will one day be able to diagnose and treat injuries right down to the molecular level. Such technology could repair and/or regenerate every cell and tissue in the body if necessary. For such technology, any patient retaining inferable brain structure (the physical basis of their mind) will be viable and recoverable. 

Yes. When carried out under favorable conditions, there is evidence to support the conclusion that cryonics has a reasonable chance of working. The degree to which cryonics is successful for a particular patient will depend on how much of the patient’s original memory and personality survives the cryopreservation and restoration process. 

Assuming future medical capabilities are as effective as we expect, complete molecular repair and tissue regeneration should permit recovery of perfect health after any injury other than complete physical destruction. Unlike medicine today, which can leave a patient alive but suffering from chronic and incurable physical or neurological deficits, mature medical capabilities based on molecular repair should be able to cure almost all medical conditions. Survival of your memories and personality depend on the extent of survival of brain structures that store your memories and other identity-critical information. 

 For further discussion of the problem of identity recovery after major brain repair, see the articles Cryonics, Cryptography, and Maximum Likelihood Estimation, Molecular Repair of the Brain, Neural Archaeology, and Prospects of a Cure for “Death”. 

To be successful, Alcor will have to keep you cryopreserved for as long as might be needed. The Alcor community is dedicated to the successful revival of the patients.  

In September of 1970, Linda and Fred Chamberlain, the founders of Alcor believed that people would someday travel to the stars. Fred searched through star catalogs and astronomy books, hoping to find a star that could serve as a fitting name for a cryonics organization. Alcor, a dim star near the bright star Mizar, has been used for centuries as a test for good eyesight. If you can see the goals and purpose of Alcor, you have excellent focus and vision. 

For the most up-to-date information about the cost of membership, click here. 

Yes! You are always welcome to schedule a tour or visit Alcor’s facility in Scottsdale, Arizona. Please contact us for more information or use our online tour reservation form. 

Embryos are frequently cryopreserved and can remain viable upon rewarming. At this point in time, no person developed beyond the embryo stage has been revived from temperatures far below freezing. Cryonics patients are cared for in the expectation that future technology will be available to reverse damage associated with the cryopreservation process. As an important proof of concept, rabbit kidneys have been cryopreserved, rewarmed, and implanted into the animal and continued to function. 

Before cryonics procedures can begin a patient must be legally dead. Legal death is a determination made by a legally qualified authority that a patient whose heart and lungs has stopped normal functioning cannot benefit from further medical care. The details of the determination depend upon care that is available, disease prognosis, and patient wishes (e.g., do-not-resuscitate order). 

The legal status of cryonics care is after-death care. There is no legal ambiguity. However, philosophically, cryonics can be regarded as an attempt to continue care in hope of future resuscitation even after today’s medicine declares that it can do no more to resuscitate someone.  

Physical conditions corresponding to legal death change over time. In the past, if someone stopped breathing, they were declared legally dead. Later, death became cessation of heartbeat. Today, a stopped heart can be restarted with CPR. As medical technology improves, the understanding of death changes. 

Given the gap between today’s medical technology and the expected capabilities of future medical technology, the difference between present and future medical criteria for determination of death is likely to persist for some time (The future of death. J Crit Care. 2014;29(6):1111-3).

Under ideal conditions, cryonics procedures can begin shortly after the heart stops beating. Blood circulation and breathing can be artificially restored, keeping cells of the brain and body alive and functioning during the early stages of cryopreservation. Cryonics may also be performed after longer periods of legal death while retaining the possibility of future repair and resuscitation. Until information theoretic death occurs, there is reason to believe a cryopreserved person might be resuscitated in the future.

The sooner cryopreservation is started, the better the expected outcome. Cryonics procedures should ideally begin within the first one or two minutes after the heart stops, after pronouncement of legal death, and preferably within 15 minutes. Longer delays place a greater burden on future technology to reverse injury and restore the brain to a healthy state. This makes it more uncertain that the correct original state can be determined. Exactly when such restoration is no longer feasible is a matter of some debate. The greatest impact of delay is that it degrades the circulatory system, reducing the ability to circulate chemicals that reduce freezing injury.  

It is unlikely that all patients will be revived at the same time. Those cryopreserved with more advanced preservation technology will probably be revived earlier than those with less advanced methods. Patients who were in a more damaged condition may not be revived until after patients with less damage. The date of attempted revival will depend not only on individual patient condition and the level of technology used when cryopreserved but also on the pace at which cryonics-related technologies improve. 

Eventually, a time may come when revival technology will be perfected. In other words, it may be possible to routinely cryopreserve and revive people for medical time travel, space travel, and other purposes. As progress continues, it may then become possible to recover people preserved at earlier times, with less perfect methods and greater degrees of injury.  

Some think it will take centuries before patients can be revived, while others think the accelerating pace of technological change might so rapidly transform our world that decades would suffice. Alcor has created robust mechanisms to care for the patients in its care for however long it may take. For more information see: Alcor’s Patient Care Trust. 

The short answer is “Alcor will revive them.”

The third item in Alcor’s mission statement is: “Eventually restore to health and reintegrate into society all patients in Alcor’s care.” 

The Alcor Care Trust, which is responsible for funding revival, grows in real value over time — compound interest should eventually produce sufficient assets to cover the costs of revival. At the same time, as technology progresses the cost of reviving patients should decrease over time. Eventually, the increasing funds available in the ACT should be sufficient to pay the costs of reviving and reintegrating patients into society. Even at 3% return, assets will increase by around 1600% over a century. 

Socially, Alcor is a community. Some members of this community are alive and healthy, while others have been cryopreserved. This community forms an interconnected network of friendships and close ties. At any point in time the healthy members of this network have friends, relatives and loved ones in cryopreservation and will seek to revive them. Once revived, those members will in turn have other friends in cryopreservation, and they will in turn seek to revive them.  

The plan is not for “them” to revive us. The plan is that we, the Alcor community, will revive ourselves. 


Alcor must wait for an independent authority to declare that illness or injury has caused the heart to stop, that further medical care is not appropriate, and that therefore legal death has occurred. Only after that determination is made can the cryopreservation procedures legally begin. 

Some states within the US and some countries have Death with Dignity laws. These arrangements must be made with your medical provider within their detailed criteria and requirements. Alcor will work with you if you choose to make this decision for yourself. Alcor members have utilized death with dignity and were successfully cryopreserved after legal death. 

Alcor uses liquid nitrogen to keep cryonics patients cold, not electricity. Liquid nitrogen refills are needed every few weeks, but electricity is not required for the patient care system. 

Alcor is a 501(c)(3) scientific and educational non-profit organization. To be tax-exempt under section 501(c)(3) of the Internal Revenue Code, an organization must be organized and operated exclusively for exempt purposes set forth in section 501(c)(3), and none of its earnings may benefit any private shareholder or individual. Non-profit organizations do not have shareholders who would be able to change Alcor’s Mission Statement to a purpose other than the benefit of the patients. 

No. Alcor does not currently offer a DNA storage option.