Rejuvenation and Regeneration

Updated June 2026. Originally published February 2021.

Rejuvenation and regeneration are progressing rapidly toward becoming mainstream medical practices to extend healthspan and lifespan. Science fiction is becoming science.

“Every generation needs regeneration.” — Charles Spurgeon, 1800s Baptist preacher

“Walk into your local drugstore, you’re going to see about 50 products that claim to be anti-aging, and I can assure you that none of them are.” — Greg Bailey, CEO Juvenescence

Data from a 2020 experiment to restore vision loss in old mice indicates that mammalian tissues retain a record of youthful epigenetic information — encoded in part by DNA methylation — that can be accessed to improve tissue function and promote regeneration in vivo. — Dr. David Sinclair and the Life Biosciences team. As of June 9, 2026, Life Biosciences has now dosed the first human patient with a cellular reprogramming therapy — moving this vision from mice to people. Keep Health covers that milestone in depth in Reversing Aging.

“Lifespan is controlled by how well your body can repair and regenerate. Young and old people take the same damage. Young people can repair and regenerate better.” — Irina Conboy

How to look, feel and actually be physically younger

As noted in What Causes Aging, two main categories of factors influence biological aging: programmed and damage-related. Programmed factors follow a biological timetable, including those regulating childhood growth and development. Damage-related factors include internal and environmental assaults that induce cumulative impairment and dysfunction, including in our DNA.

Defying aging is a continuous four-part process:

For older adults, rejuvenate your body to its desired youthful state.
Stop the programmed aging process. (See Reversing Aging.)
Repair damage rapidly through healing and regeneration.
Don’t die. (See Brain and Body Protection.)

This article focuses on #1 (Rejuvenation) and #3 (Healing and Regeneration).

Rejuvenation targets

As people age, what do you notice most? Wrinkled skin? Loss of muscle tone and flexibility? Loss of hair? Dwindling eyesight? Impaired brain function?

Commercial research now targets multiple areas for whole-body rejuvenation:

Blood and Plasma
Brain
Cells (see Cellular Reprogramming)
Eyes (see 2020 Vision Eye Care)
Hair (see Keep Hair)
Muscles (see Strength Training: Power Up! and Flexibility and Pliability)
Skin (see Feel Comfortable in Your Own Skin)

This article covers Blood and Plasma rejuvenation and Brain rejuvenation in detail. The latest scientific research on Blood and Plasma rejuvenation has produced the first positive human trial data — and its effects reach directly into the youthfulness of your brain, eyes, hair, muscles and skin.

Blood and plasma rejuvenation — clean out accumulated junk

A major key to rejuvenation is cleansing your blood plasma. You may have heard of experiments transfusing young blood into old people to rejuvenate them. Scientifically thin companies such as Ambrosia were shut down by the FDA as a scam in February 2019. Under any name — including its brief reincarnations as Ivy Plasma and Ambrosia Plasma — those services are not a good health risk.

Expert scientists led by Drs. Irina and Michael Conboy at the Conboy Laboratory for Engineering Longevity looked deeper into the early research and made a fascinating discovery. The young blood itself wasn’t the benefit. Rather, the benefits traced to removing the old blood plasma and its accumulated protein debris, which biologically interferes with youthful, healthy processes. This resembles ongoing research to remove senescent cells from the body, but blood dilution goes further than just limiting SASP (Senescence-associated secretory phenotype). Dilution removes the main toxic components: myostatin and elevated TGF-beta family proteins, both of which inhibit regeneration.

The Conboys demonstrated in animals that aged blood can be filtered of pro-aging factors, producing rejuvenated, biologically younger mice. Their IMYu startup partnered with plasma expert Dr. Dobri Kiprov to develop improved filtration methods using an FDA-approved procedure called therapeutic plasma exchange (TPE) — similar to kidney dialysis but targeting harmful proteins rather than toxins.

Major update — first positive human trial published May 2025. A randomized, single-blinded, placebo-controlled trial conducted by Circulate Health and the Buck Institute for Research on Aging, published in Aging Cell on May 28, 2025, enrolled 42 adults and tracked them across 36 different epigenetic clocks — measuring biological age changes across the epigenome, proteome, metabolome, glycome, and immune system. The results: participants receiving biweekly TPE combined with intravenous immunoglobulin (IVIG) showed an average biological age reduction of 2.61 years. Monthly TPE alone produced a 1.32-year reduction. This is the first clinical trial to demonstrate that TPE measurably reverses biological age in humans using comprehensive multi-omics profiling. The lead researchers note these are biomarker signals rather than clinical outcomes, and that larger trials with longer follow-up are needed to confirm the durability and scope of the effect.

Plasma is 90%–95% salt water, making up a little more than half of the body’s blood volume. The primary plasma protein is albumin, which regulates which molecules move into tissues from the bloodstream — and which waste products get removed. Cleaning blood plasma therefore allows tissues and organs to dispose of unhealthy waste products more effectively.

The Conboys’ GeroScience 2022 study of three people showed that old people reset to younger states through TPE, regaining younger blood proteins that control brain health, homeostasis, regeneration, and immune responses. The 2025 Aging Cell trial extends this with a controlled design and much larger measurement scope.

Companies working on plasma rejuvenation:

Circulate Health

Backed by Khosla Ventures; led the 2025 Aging Cell trial in partnership with the Buck Institute and Dr. Dobri Kiprov
Advancing TPE as a longevity-focused clinical service, building on the first positive randomized controlled trial data in the field

Elevian

Developing therapeutics that regulate Growth Differentiation Factor 11 (GDF11) and other circulating factors to restore the body’s natural regenerative capacity
GDF11 promotes blood vessel formation and declines with age; supplementation reduces cardiac hypertrophy, accelerates muscle repair, improves brain function, and improves metabolism
Important caveat: GDF11 carries a meaningful association with cancer growth, making it a risky target — approached carefully

Alkahest — Acquired by Grifols

Originally developing clinical candidates targeting specific age-related blood proteins (chronokines) for neurodegeneration, cognitive decline, and ophthalmic conditions
Grifols completed the acquisition in 2021 for $146 million and continues chronokine research as a Grifols subsidiary, particularly mapping the human plasma proteome for age-related therapeutic targets
Early clinical trials struggled to identify validated targets; research continues

NuGenics Research

Drs. Harold Katcher and Steve Horvath conducted plasma experiments that dramatically reduced the biological age of old rats
This conflicts with the Conboy team’s position that protein removal — not young protein addition — drives the effect
No updates have emerged since 2020; website appears inactive

Brain rejuvenation — avoid age-related functional and memory loss

Impaired brain function is perhaps the most frightening aspect of aging — losing the ability to think quickly, focus, recall words, and access memories. Here is the top research on what’s possible today:

As we age, increasing brain stiffness causes dysfunction of brain stem cells needed for normal function and the regeneration of myelin — the fatty sheath surrounding nerves. A protein called Piezo1 on the cell surface informs cells whether their surrounding environment is soft or stiff. Deleting Piezo1 in stem cells within elderly rat brains led to cellular rejuvenation, restoring their normal regenerative function.
The hypothalamus plays a crucial role in controlling aging. At the Albert Einstein College of Medicine, Dr. Dongsheng Cai’s team identified neural stem cells in the hypothalamus as responsible for the pace of aging, and showed the process can be counteracted by adding fresh stem cells — though that’s obviously not a practical consumer solution yet.
Athira Pharma (NASDAQ: ATHA) focuses on restoring neuronal health through small molecule therapies promoting natural brain repair. The company has candidates targeting neurodegeneration in early clinical development.
Healing scar tissue from brain injuries is now also possible. Research from Dr. Gong Chen showed glial tissue can be reversed back to neuronal tissue through neuroregenerative gene therapy involving four core molecular switches.
A 2020 study demonstrated that inhibiting intracellular brain stress restored youthful brain function in mice, adding another potential therapeutic pathway to the brain rejuvenation toolkit.

For more on protecting brain health, see Connect With Your Brain and Outthink Your Brain.

Healing and regenerative medicine: growing cells, tissue, organs and limbs

On any given day, roughly 330 billion cells in the body die and get replaced by new ones. Within about 80 days, enough cells are replaced to match your body weight. The Weizmann Institute in Israel has created a baseline for the composition of cell types in the human body and is analyzing how these replacement capabilities are lost with age.

Although all animals can heal wounds, some organisms reconstruct their entire bodies from small fragments. Research on the genetics of whole body regeneration at Harvard has yielded discoveries directly applicable to human healing.

Leading-edge work to heal and regenerate cells, tissue, organs, and limbs:

Wake Forest Institute of Regenerative Medicine — led by Anthony Atala

Around 400 researchers have engineered human replacement tissues and organs across four categories: flat structures, tubular tissues, hollow organs, and solid organs
In human patients, 15 cell and tissue therapy technologies have been used — including skin, urethras, cartilage, bladders, muscle, kidneys, and vaginal organs
Here’s how they do it using 3D bioprinting

Xenotransplantation — growing organs in pigs for humans

One of the most dramatic developments in regenerative medicine since this article was first published: xenotransplantation — transplanting gene-edited pig organs into humans — has moved from science fiction to FDA-approved clinical trials.

eGenesis and United Therapeutics / Revivicor lead the field:

March 2024: Massachusetts General Hospital performed the first transplant of an eGenesis gene-edited pig kidney into a living human patient (Richard Slayman). He died approximately two months later, though doctors confirmed the kidney itself was not the cause of his death.
The eGenesis pig undergoes 69 gene edits — including inactivating 59 genes to remove integrated pig viruses and adding human compatibility genes.
United Therapeutics’ UKidney uses 10 gene edits (six human genes added, four pig genes inactivated including one restricting organ growth and three triggering human rejection).
January 2025: Tim Andrews received an eGenesis kidney at Massachusetts General Hospital. By June 2025, he threw the first pitch at Fenway Park for a Boston Red Sox game — one of the more vivid demonstrations in the history of medicine that a procedure worked.
September 2025: The FDA granted investigational new drug (IND) clearance for a formal Phase I/II/III clinical trial of eGenesis’s EGEN-2784 pig kidney.
February 2025: The FDA approved United Therapeutics / Revivicor to begin a formal xenotransplantation clinical trial — the first multi-patient regulatory approval in this field.

Both companies now have FDA-approved clinical trials underway. The xenotransplantation era has formally begun. The primary challenges remaining are immunological: current pig kidney transplants can last months to a couple of years in some patients, but durable long-term outcomes require further refinement of gene editing, immunosuppression regimens, and patient selection.

More than 100,000 people in the US wait for kidney transplants; roughly 13 people die each day waiting. Successful xenotransplantation would effectively eliminate the organ shortage for kidneys — and potentially extend to hearts, livers, and lungs over the following decade.

Other regenerative medicine approaches:

Prellis Biologics and over 20 other commercial companies are working on human tissue and organ bioprinting.
Morphoceuticals (using bioelectrics), LyGenesis (using lymph nodes as bioreactors to regrow organs), and Juvena Therapeutics (novel signaling proteins that regenerate any tissue type) are creating ways to initiate regeneration in living patients.
The Allen Discovery Center at Tufts, led by Dr. Michael Levin, works on using bioelectric signaling to induce targeted regeneration.
AgeX Therapeutics (NYSE American: AGE) received an NYSE non-compliance notice in 2023 and has struggled financially. Its induced Tissue Regeneration (iTR™) platform and cell therapy candidates — AGEX-VASC1 (vascular progenitor cells for tissue ischemia) and AGEX-BAT1 (brown fat cells for type 2 diabetes) — remain in preclinical stages. The company continues to seek licensing and collaboration partnerships to remain viable.
Turn.Bio attempted, but failed, to create mRNA medicines that instruct specific cells to fight disease or repair damaged tissue through epigenetic reprogramming. The company has ceased operations.

Hyperbaric oxygen therapy and red light therapy

For information on Hyperbaric Oxygen Therapy and Red Light Therapy for rejuvenation, Keep Health’s dedicated articles on each cover the research and practical applications.

The bottom line

Rejuvenation and regeneration have crossed a meaningful threshold since this article was first published. The first controlled human trial of therapeutic plasma exchange demonstrated measurable biological age reversal — 2.61 years on multi-omics biomarkers — in a placebo-controlled study published in 2025. Gene-edited pig kidneys moved from experimental procedures in deceased patients to FDA-approved clinical trials in living recipients across 2024 and 2025. On June 9, 2026, Life Biosciences dosed the first human participant in a cellular reprogramming trial.

None of these are ready for broad clinical use. Each represents an early-stage clinical milestone in a field where the gap between promising results and proven, durable human therapies remains substantial. However, the direction of travel is clear: the tools to rejuvenate and regenerate human bodies are advancing from concept to clinical trial at an accelerating pace.

For more on the science underpinning these developments, see Cellular Reprogramming, Reversing Aging, Your Bioelectric Body, and Preventing Age-Related Diseases.

As your reward for focusing on your health today, watch this powerful TED Talk by physician Sangeeta Bhatia on tiny liver-inspired particles that could roam your body to find and treat disease — a vivid illustration of how regenerative medicine is beginning to reach inside us at the cellular level.