E5 Plasma Fraction
E5 (purified plasma fraction from young pigs)
Written by Aaron CuhaReviewed Sep 2026
Also known as: E5, Young porcine plasma fraction, Plasma fraction treatment
A purified fraction of plasma from young pigs, given to old rats, which more than halved epigenetic age in blood, heart and liver. No human has received it.
Overview
E5 is a purified fraction of plasma taken from young adult pigs. The single study behind it, published in GeroScience in 2024, first developed and validated six epigenetic clocks for rat tissues using 613 tissue samples, including two clocks that work across both human and rat tissues, then used those clocks to measure what the porcine plasma fraction did to old rats.
The reported result is large. Treatment more than halved the epigenetic ages of blood, heart and liver tissue, with a smaller but statistically significant effect in the hypothalamus. The authors report that this was accompanied by progressive improvement in the function of those organs across biochemical, physiological and behavioural measures including cognitive tests, and by a shift in immunoglobulin G N-glycosylation from a pro-inflammatory to an anti-inflammatory pattern. The work had NIH support along with non-US government funding.
No human has received E5. There is no registered human trial of a porcine plasma fraction for ageing on ClinicalTrials.gov. A cross-species plasma product raises specific questions, including immunogenicity and the risk of transmitting porcine endogenous retroviruses, that a rat study is not designed to answer. Nothing published tells you what would happen if this were given to a person.
Mechanism of action
Not established, in any species. The paper measures outcomes, chiefly epigenetic clock readings and organ function markers, rather than identifying which component of the fraction acts on what. The active constituent has not been named. That is the ordinary position for whole-plasma and plasma-fraction interventions, and it is why the field's serious drug work is on individual identified factors such as TIMP2, platelet factor 4 and Gpld1 rather than on mixtures.
Human evidence
None. No human has received E5 or any young porcine plasma fraction. There is no registered human trial and no published human safety, pharmacokinetic or biomarker data of any kind.
What this does not tell you: A rat result of this size is worth reporting and tells you nothing about a person. Beyond the ordinary species gap, this is a cross-species biological product, which raises immunogenicity and xenotransmission questions that no published work has addressed, and the active constituent has never been identified, so there is nothing to characterise, dose or manufacture to a standard. The primary outcome measured is an epigenetic clock, which is a correlational marker; the paper also reports functional improvements, which is a stronger claim, but all of it is in rats.
Reading the research record
One paper, one laboratory, one species, no replication. That is the whole record, and it is stated here plainly because the headline number, more than halving epigenetic age in three organs, is the kind of figure that travels a long way from its source. The paper is well constructed on its own terms: the authors built and validated the rat clocks first, which is more care than most animal epigenetic ageing work takes, and they report functional measures alongside the clocks rather than clocks alone.
The comparison that matters is the mouse plasma dilution work published in Aging in 2020, which found that exchanging half the plasma volume for saline plus albumin, adding nothing young at all, matched the effects attributed to young blood. If that is right, a young plasma fraction may be working by removing old plasma rather than by supplying anything. No experiment has been run that separates those explanations for E5 specifically.
No company programme for this product is registered on ClinicalTrials.gov. Where a research doc or a press account describes a human programme, the registry is the check, and the registry is empty.
The evidence, charted
Fig. 1 · evidence composition
0of 4 citations (0%) are in people
Every citation cited here is Animal work; no other study type is cited on this page. This count is of our own citation list and understates any literature larger than the sources we cite.
Fig. 2 · evidence over time
Evidence spans 4 distinct years, 2011 to 2024, counted from the citation list on this page.
Fig. 3 · legal status at a glance
US
Not approved
UK
Approved
AU
Approved
CA
Not approved
Approved in 2 of 4, prescription route in 0, not approved in 2. A jurisdiction's classification is a regulatory fact, not a verdict on the science; see Legal status below for the full text and any notes.
Fig. 4 · dose response
No human dose response curve exists
We draw this figure where the data supports it. For this compound in humans it does not, so the panel stays empty rather than borrowing an animal curve and implying it transfers.
Key studies & citations
- Animal2024
Reversal of biological age in multiple rat organs by young porcine plasma fraction
Rat. Six epigenetic clocks were developed and validated for rat tissues from 613 tissue samples, with two clocks trained on an additional 1,366 human tissue samples to work across both species. A young porcine plasma fraction treatment more than halved the epigenetic ages of blood, heart and liver tissue in old rats, with a smaller but statistically significant effect in hypothalamus, accompanied by improvements in biochemical, physiological, behavioural and cognitive measures and a shift in immunoglobulin G N-glycosylation from pro- to anti-inflammatory. NIH supported with non-US government funding.
GeroScience - Animal2011
The ageing systemic milieu negatively regulates neurogenesis and cognitive function
Mouse. The heterochronic parabiosis experiment that established that blood-borne factors can inhibit or promote adult neurogenesis in an age-dependent way, and that plasma from old mice impairs synaptic plasticity, contextual fear conditioning and spatial learning in young mice.
Nature - Animal2020
Rejuvenation of three germ layers tissues by exchanging old blood plasma with saline-albumin
Mouse, and the most important comparison for this page. A single exchange of half the plasma volume for saline containing 5 percent albumin, with no young plasma added at all, met or exceeded the effects of young blood on muscle repair, liver adiposity and fibrosis, and hippocampal neurogenesis. If dilution alone can reproduce the effect, the case that a young plasma fraction contains a specific rejuvenating agent becomes harder to make.
Aging (Albany NY) - Animal2017
Human umbilical cord plasma proteins revitalize hippocampal function in aged mice
Mouse. Human umbilical cord plasma improved hippocampal function and cognition in aged mice, and TIMP2 was identified as a specific blood-borne factor necessary for that benefit. This is the alternative research strategy to whole-fraction dosing: find the molecule.
Nature
Frequently asked questions
Has E5 been given to a human?
No. There is no published human study and no registered human trial of a porcine plasma fraction for ageing. Everything known about it comes from one paper in old rats.
What did it do in rats?
It more than halved the epigenetic ages of blood, heart and liver tissue and produced a smaller significant effect in the hypothalamus, with reported improvements in organ function across biochemical, physiological, behavioural and cognitive measures, and a shift in immunoglobulin G glycosylation toward an anti-inflammatory pattern. One paper, one laboratory, no independent replication.
Is a pig plasma product safe to give a person?
Nobody knows, because nobody has published doing it. A biological product from another species raises immunogenicity questions and xenotransmission questions that a rat study does not address, and the active component of E5 has never been identified.