Plasma Exchange (Therapeutic Plasma Exchange)

Therapeutic plasma exchange (TPE), removing a patient's blood plasma and replacing it with albumin or donor plasma, sometimes combined with intravenous immunoglobulin (IVIG), has moved from a treatment for autoimmune disease into experimental longevity use on the theory that plasma carries age-related inflammatory and pro-aging signaling factors that dilution can remove.

The core supporting trial comes from Circulate Health and the Buck Institute: a single-blind, placebo-controlled study in adults over 50 found biweekly TPE combined with IVIG reduced biological age by 2.61 years as measured by epigenetic clocks, compared to 1.32 years for TPE alone, published in Aging Cell in May 2025 [1]. A related peer-reviewed report on the same trial found 15 different epigenetic clocks showed statistically significant rejuvenation signals relative to placebo (false discovery rate under 0.05) [2]. A preprint version of the same underlying study described the therapy as reversing markers of age-related immune decline [3].

The featured counter-finding is a real and important one: this is a single trial, run and funded by a company, Circulate Health, that sells TPE-based longevity treatments commercially and holds patents on aspects of the protocol [4]. No independent, non-industry-funded laboratory has yet replicated these specific biological-age reduction figures. The company's own materials describe itself as an 'industry pioneer' in this space, language that signals commercial rather than purely academic framing of the results. A related, larger sham-controlled trial (ClinicalTrials.gov NCT06534450) was still recruiting or in progress at time of writing, meaning the field's most rigorous ongoing test of TPE's longevity claims had not yet reported final results [5].

Who this does not work for, or where the evidence is weakest: TPE is an invasive procedure requiring intravenous access and carries real, if generally low, procedural risks, including infection, blood pressure changes, and allergic reaction to replacement fluids, risks that matter more given how thin the independent efficacy evidence currently is. The epigenetic-clock outcome measures used across these trials are themselves imperfect proxies for true biological aging rate, not a validated surrogate for actual lifespan or healthspan extension. Given the single-company funding source and the absence of independent replication, this intervention sits closer to a promising but commercially entangled early signal than to an established therapy, and anyone considering it should weigh that a company with a direct financial stake in positive results designed, ran, and published the primary supporting trial.

Mechanistically, TPE is proposed to dilute or remove circulating pro-inflammatory and pro-aging plasma proteins that accumulate with age, plausible given parabiosis research in animal models showing young blood plasma can partially reverse aging phenotypes in old mice, though the human TPE evidence remains far earlier-stage than that animal literature might suggest.

Plain takeaway: a single industry-funded, placebo-controlled trial found TPE, especially combined with IVIG, reduced measured biological age by roughly 1.3 to 2.6 years using epigenetic clocks, a genuinely interesting result, but it comes from one company with a direct commercial stake in the outcome, has not been independently replicated, and rests on epigenetic-clock proxies rather than measured lifespan or healthspan outcomes.