Peptides/Longevity
FOXO4-DRI
Also sold as FOX04-DRI, Senolytic peptide, Proxofim
The senolytic peptide from one striking 2017 mouse paper, built to clear the cells that stop dividing but refuse to die.
At a glance
What people use it for
- Marketed for clearing senescent cells
- Sold for ageing and tissue repair
- Promoted for hair and kidney function, from the mouse data
How it is taken
Sold as a powder for injection, usually in short courses.
Evidence
No human trials yet
Best known for
- A designed peptide, not a natural one
- Built as a retro-inverso sequence, so it resists being broken down
- The 2017 mouse paper reported restored fur, kidney function and exercise capacity
- Targets senescence, one of the most discussed mechanisms in ageing research
FOXO4-DRI is a designed peptide, not a natural one. It is built as a retro-inverso sequence, meaning the amino acids run in reverse order and in mirror-image form, which makes it resistant to being broken down.
It exists because of one paper in Cell in 2017, and almost everything sold and said about it traces back to that paper.
Why people are talking about it
Senescent cells. They are cells that have stopped dividing but refuse to die, and they accumulate with age while releasing inflammatory signals into the tissue around them. Clearing them is one of the most actively pursued ideas in ageing research.
The 2017 results are the other reason. In aged mice the paper reported restored fur density, improved kidney function and better exercise capacity, which is about as vivid a set of outcomes as animal ageing research produces.
What people take it for
Clearing senescent cells, which is the entire pitch.
Killing senescent cells
The claim is that the cells driving age-related inflammation are removed while healthy cells are left alone. The mechanism is genuinely clever: senescent cells survive by sequestering p53, a protein that would otherwise trigger their death, and FOXO4-DRI is designed to disrupt that interaction and let the death signal through.
In practice that describes removing a cell's excuse for staying alive. That was demonstrated in aged mice.
What the evidence shows
One influential mouse study, published in a leading journal, with striking results. That is the substance of it.
There is no human trial, no dose-finding work in people, no human pharmacokinetics, and no independent replication of the mouse results at the scale the claim would need. Nine years after publication, a result that transformative would normally have attracted a great deal of follow-up, and the relative quiet since is worth noticing.
Because no human has taken it in a controlled setting, there is no side effect profile to describe either.
How it is taken
Sold as a powder for reconstitution and injection, usually in short courses on the reasoning that senescent cells need clearing periodically rather than continuously.
No dose has been established in people. The retro-inverso construction is also harder to synthesise correctly than an ordinary peptide, which is part of why it is among the most expensive vials in the market.
How it compares
Against the other senolytic approaches
Small-molecule senolytics such as the dasatinib and quercetin combination have reached early human trials, which is further than this peptide has gone. They are the comparison worth tracking.
Against the other longevity peptides
Epitalon targets telomeres and MOTS-c targets mitochondrial signalling. FOXO4-DRI has the most dramatic single result and the thinnest overall evidence base of the three.
Common questions
Has anyone taken it in a trial?
No. There has been no human trial of any phase.
Did the mouse study really show that?
It reported restored fur density, improved kidney function and better exercise capacity in aged mice. Those are the results; what they mean for a person has not been tested.
Why is it so expensive?
Retro-inverso peptides are harder to make, and the market bears the price.
What does retro-inverso mean?
The sequence runs backwards and each amino acid is the mirror image of the natural form, which together make the molecule much harder for the body's enzymes to break down.
Last reviewed .