Plasma exchange for aging
Therapeutic plasma exchange removes part of a person's own blood plasma and replaces it with an albumin solution, on the theory that diluting pro-aging factors in old blood rejuvenates tissues. It grew out of mouse experiments joining old and young animals. In healthy people, the one sham-controlled trial found a biological-age shift midway that had disappeared by the end. It should not be confused with commercial "young plasma" infusions, which the US regulator has warned against.
Don't buy young-plasma infusions, and treat plasma exchange for aging as an experiment: in healthy adults the evidence is biomarker-only and short-lived.
Where the idea came from
The thinking traces to parabiosis: surgically joining the circulations of an old and a young mouse, which restored the repair capacity of aged muscle and liver stem cells.[1] That result launched a hunt for youthful "rejuvenation factors" in blood. Parabiosis has since produced a lifespan result: old female mice joined to young partners for three months and then separated lived a median of about six weeks longer than old mice joined to old partners,[2] though a second lab using a similar design found only a small, non-significant gain, and its young partners died sooner.[3]
The cautionary tale: GDF11
A circulating protein called GDF11 was reported to reverse age-related decline in mouse muscle,[4] but an independent team could not reproduce this. They found that the tests used could not tell GDF11 apart from a near-identical protein (myostatin), and that extra GDF11 actually hindered muscle repair in mice.[5] Even whether GDF11 levels change with age is still disputed: a later human study using a test specific to GDF11 found that its levels did not fall with age.[6] It is a textbook case of a young-blood claim that did not hold up.
From adding youth to diluting age
Later mouse work reframed the benefit: much of what parabiosis achieves may come from diluting the pro-aging factors in old blood rather than adding youthful ones. Simply exchanging old plasma for a neutral saline-albumin solution reproduced part of the effect.[7]
What happened in people
- An uncontrolled start. A study of 8 people with no comparison group reported younger-looking blood-protein profiles after repeated exchanges.[8]
- The first sham-controlled trial. It enrolled 44 healthy adults over 50, of whom 42 finished, and compared plasma exchange with a fake treatment (sham). The procedure was well tolerated. Midway through, it lowered blood-based biological-age estimates by about 1.3 years on average, or about 2.6 years when combined with an immunoglobulin infusion. At that point, fifteen of the 36 DNA-methylation clocks measured showed rejuvenation relative to sham, while the sham arm moved on none. By the end of the study the difference from the sham group had disappeared. An exploratory analysis hinted that people whose routine blood tests sat at the less healthy end of the normal range showed the biggest clock changes, but other markers pointed the other way, every participant's values were within the normal range, and each group held only about eleven people.[9]
- An independent trial moved the clocks the other way. In 34 healthy first-time plasma donors aged 40 to 60, removing plasma four or eight times over 18 weeks without replacing it, as in routine plasma donation, made no epigenetic clock look younger; three aging measures moved slightly in the older direction, which the authors suggest may be a stress response to the procedure. This is not the same procedure as exchange with albumin.[10]
- In Alzheimer's disease, a large trial had a mixed result. In 347 people with mild-to-moderate Alzheimer's, about 14 months of plasma exchange with albumin slowed the loss of everyday-living abilities by about half compared with sham, memory and thinking scores fell just short of significance, the benefit was seen in people at the moderate stage but not the mild one, and the albumin maker sponsored it. It tested a disease, not healthy aging.[11]
The first sham-controlled trial (above) has three further limits: participants were assigned in order of sign-up rather than truly at random, no health or function outcomes were measured, and several authors work for a plasma-exchange company. In healthy adults, the evidence is biomarker-only and preliminary.
Young plasma is a different thing, and a trap
Commercial "young plasma" infusions transfuse plasma from young donors. In 2019 the US Food and Drug Administration (FDA) warned that they have no proven benefit against aging or memory loss and carry infection, allergy, lung and heart risks.[12] Unproven stem-cell injections are a similar trap; see stem-cell therapy.
What to do
- Skip young-plasma infusions. They are unproven and carry real transfusion risks.
- Read plasma-exchange claims for aging as biomarker results, not evidence that you will live longer or function better.
- If you are curious, wait for or join a properly randomised trial with health outcomes, and see stem-cell exhaustion for the levers with better evidence.
Further reading
- Conboy IM, et al. Rejuvenation of aged progenitor cells by exposure to a young systemic environment. Nature 2005.[13]
- Egerman MA, et al. GDF11 Increases with Age and Inhibits Skeletal Muscle Regeneration. Cell Metab 2015.[14]
- Mehdipour M, et al. Rejuvenation of three germ layers tissues by exchanging old blood plasma with saline-albumin. Aging (Albany NY) 2020.[15]
- Fuentealba M, et al. Multi-Omics Analysis Reveals Biomarkers That Contribute to Biological Age Rejuvenation in Response to Single-Blinded Randomized Placebo-Controlled Therapeutic Plasma Exchange. Aging Cell 2025.[16]
- Borsky P, et al. Human clinical trial of plasmapheresis effects on biomarkers of aging (efficacy and safety trial). Sci Rep 2025.[17]
- Boada M, et al. A randomized, controlled clinical trial of plasma exchange with albumin replacement for Alzheimer's disease: Primary results of the AMBAR Study. Alzheimers Dement 2020.[18]