Head to head
Therapeutic Plasma Exchange against Plasma Dilution
The clinical procedure and the mouse experiment that explains why it might work at all. Both point at removal rather than addition, and two small 2025 randomised trials of ageing biomarkers on the clinical version reached opposite conclusions.
Column A
Therapeutic Plasma ExchangeTherapeutic plasma exchange (plasmapheresis with albumin or albumin plus immunoglobulin replacement)
An established medical procedure that removes plasma and replaces it with albumin. A 347-patient randomised trial in Alzheimer disease met one of two co-primary endpoints, and two small 2025 randomised trials of ageing biomarkers reached opposite conclusions.
Column B
Plasma DilutionPlasma dilution (neutral blood exchange with saline and albumin)
The mouse experiment that asked whether young blood is necessary at all. Replacing half the plasma with saline plus albumin, adding nothing young, matched the effects attributed to young blood.
Side by side, on the facts we can check
| Attribute | Therapeutic Plasma Exchange | Plasma Dilution |
|---|---|---|
| Category | Longevity | Longevity |
| FDA status | Therapeutic plasma exchange is an established medical procedure performed with cleared apheresis devices and has recognised indications in neurological, haematological and renal disease. It is not approved for ageing, biological age reduction or Alzheimer disease anywhere. | Not approved anywhere as an ageing intervention, and not registered as a human trial under this name. The closely related human procedure, therapeutic plasma exchange, is an established medical treatment with its own indications. |
| Half-life | Not reported | Not reported |
| Molecular weight | Not reported | Not reported |
| Mechanism | Two competing accounts, neither settled in humans. The dilution account, developed in mice, holds that removing a fraction of old plasma dilutes age-elevated autoregulatory proteins and resets systemic signalling, and that the replacement fluid is secondary; the 2020 mouse work found that saline plus albumin exchange matched the effects of young blood. The replacement account holds that the albumin itself matters, either by binding and carrying away circulating ligands or by restoring binding capacity; this is the rationale for the AMBAR protocol, in which albumin is the replacement product. The 2025 Scientific Reports trial, which removed plasma without replacing it with albumin and saw epigenetic clocks move in the wrong direction, is a data point against dilution alone being sufficient, though a single small crossover trial does not settle it. | Established in mice only. The proposal is that plasma contains autoregulatory proteins whose concentrations feed back on their own production and on multiple signalling pathways, so that diluting them resets those pathways and produces durable transcriptional changes rather than a transient concentration drop. Albumin was added to the exchange fluid to replace what saline alone would have diluted, and the authors state that ectopically added albumin does not appear to be the sole determinant of the effect, noting that albumin levels do not fall with age and do not rise after exchange. The mechanism has not been demonstrated in a person. |
| Human studies cited | 7 | 2 |
| Legal status, US | Approved medical procedure; not approved for ageing indications | Investigational, not approved |
Frequently asked questions
What is the difference between Therapeutic Plasma Exchange and Plasma Dilution?
Therapeutic Plasma Exchange: An established medical procedure that removes plasma and replaces it with albumin. A 347-patient randomised trial in Alzheimer disease met one of two co-primary endpoints, and two small 2025 randomised trials of ageing biomarkers reached opposite conclusions. Plasma Dilution: The mouse experiment that asked whether young blood is necessary at all. Replacing half the plasma with saline plus albumin, adding nothing young, matched the effects attributed to young blood.
Which has stronger research evidence, Therapeutic Plasma Exchange or Plasma Dilution?
This database does not grade compounds. It counts what was run in people: 7 of the 7 studies cited on the Therapeutic Plasma Exchange profile were human work, against 2 of 4 for Plasma Dilution. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are Therapeutic Plasma Exchange and Plasma Dilution FDA-approved?
Therapeutic Plasma Exchange: Therapeutic plasma exchange is an established medical procedure performed with cleared apheresis devices and has recognised indications in neurological, haematological and renal disease. It is not approved for ageing, biological age reduction or Alzheimer disease anywhere.. Plasma Dilution: Not approved anywhere as an ageing intervention, and not registered as a human trial under this name. The closely related human procedure, therapeutic plasma exchange, is an established medical treatment with its own indications..
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.