Overview

FOXO4-DRI is a lab-made peptide designed to kill 'senescent' cells, old damaged cells that stop dividing but linger and cause inflammation. A 2017 mouse study made headlines when it restored fur, fitness and kidney function in old mice. It has never been tested in a published human trial.

How it works

Proposed from cell and animal studies. In senescent cells, the protein FOXO4 binds p53 in the nucleus and helps keep those cells alive instead of letting them self-destruct. FOXO4-DRI is designed to block that FOXO4-p53 contact; p53 is then pushed out of the nucleus and the senescent cell undergoes apoptosis (programmed cell death), while normal cells appear largely spared ¹. Later mouse and cell studies reported the same pathway, with activation of BAX and cleaved caspase-3 ³. Not established in humans.

What research shows

Baar et al. 2017, Cell (mouse and cell study): FOXO4-DRI selectively triggered death of senescent cells, countered doxorubicin chemotherapy toxicity, and restored fitness, fur density and kidney function in fast-aging and naturally aged mice ¹.
Zhang et al. 2020, Aging (cell and aged-mouse study): raised blood testosterone and lowered senescence markers in aged male mice; authors note no direct proof that senescent Leydig cells were removed in vivo ².
Huang et al. 2021, Front Bioeng Biotechnol (lab study): removed many senescent cells from expanded human cartilage cells but did not improve cartilage-forming ability in standard culture ⁴.
Hu et al. 2026, Front Bioeng Biotechnol (aged and prematurely aged mice, endothelial cells): reduced aortic senescence markers and improved arterial stiffness; authors say the work is still preclinical ³.
No published human trials were found.

Doses studied in people

No published human dosing data exist; doses circulating online are extrapolated from mouse studies (typically given by injection into the abdomen).

Read this first: these are the amounts given to participants in published studies or written on official prescribing labels, reported for reference. They are not recommendations. Trial doses were chosen for specific patients under medical supervision, and a dose that is safe in one person can be harmful in another.

Weekly protocol

How the schedule looks week by week. Each chart says where it comes from: a prescribing label, a clinical trial, or a protocol commonly reported online.

PeptideDosages.com daily protocol

Commonly reported, not studied

One week

D1D2D3D4D5D6D7

Once daily · Subcutaneous injection

Syringe units (U-100)

Vial Water added

Dose by week

250 mcgwk 1–4

375 mcgwk 5–8

500 mcgwk 9–16

Supplies for one course (estimate)

Counts only. This site does not sell or link to supplies.

Course: 8–16 weeks
Note: No human safety or efficacy data exist.
Source: PeptideDosages.com: FOXO4-DRI (10 mg vial) dosage protocol

Short 'hit-and-run' course

Commonly reported, not studied

One week

D1D2D3D4D5D6D7

Every other day · Subcutaneous injection

Syringe units (U-100)

Vial Water added

Dose by week

3–25 mg per injection (highly variable)wk 1–2

Supplies for one course (estimate)

Counts only. This site does not sell or link to supplies.

Course: 3–6 doses per course, repeated 1–3 times a year
Note: Loosely modelled on the mouse study (5 mg/kg IV three times a week). No established human dose.
Source: Peptide Protocol Wiki: FOXO4-DRI dosing protocols

Reference only, not a recommendation. Charts marked "commonly reported" describe what public sources say people use. They have not been tested in trials, and their safety and effect are unknown. Label and trial schedules were set for specific patients under medical supervision. Use the calculator only to understand the arithmetic.

Vial math

Many research vials hold 5 or 10 mg of powder. This table shows how much ends up in each mark on a U-100 insulin syringe for common amounts of added liquid. It is arithmetic only, not a dose.

Vial	Liquid added	Concentration	Per unit (0.01 mL)
5 mg	1 mL	5 mg/mL	50 mcg	Open in calculator
5 mg	2 mL	2.5 mg/mL	25 mcg	Open in calculator
5 mg	3 mL	1.67 mg/mL	16.7 mcg	Open in calculator
10 mg	1 mL	10 mg/mL	100 mcg	Open in calculator
10 mg	2 mL	5 mg/mL	50 mcg	Open in calculator
10 mg	3 mL	3.33 mg/mL	33.3 mcg	Open in calculator

More sizes: all vial sizes · How this works: Syringes and units · Reconstitution guide.

Safety

No human safety data; short- and long-term risks are unknown.
In mice it was reported as well tolerated over short courses ¹, but mouse tolerance does not predict human safety.
p53 is a key tumor-suppressor protein; the long-term effect of altering its location in cells has not been studied in people.
Unregulated 'research' products may vary in purity and identity.

Report side effects of any drug or product to the FDA through MedWatch. For a possible poisoning in the US, call Poison Control at 1-800-222-1222.

Legal status

FDA: Not FDA-approved; no published human trials.
Compounding: Not named on FDA's 503A Category 2 page or withdrawn-nominations table (current as of 04/22/2026), and not found on FDA's 503A nominations list as retrieved ⁶⁷.
Sports (WADA): Not named on the 2026 Prohibited List. As a substance with no government approval for human use, it would likely fall under S0 (non-approved substances, prohibited at all times); athletes should confirm with their anti-doping organization ⁸.
Other: No approval in any country found.

Rules change often. See Legal status of peptides for how these categories work.

History

Developed by Peter de Keizer and colleagues at Erasmus University Medical Center in the Netherlands, with collaborators including Judith Campisi; published in Cell in 2017 ¹. A start-up, Cleara Biotech, was later formed to develop therapies based on the FOXO4-p53 concept, and has remained preclinical according to a 2026 commentary ⁵. Independent groups have since tested it in aged-mouse Leydig cells (2020), human cartilage cells (2021) and blood vessels (2026) ²⁴³.

Common questions

Has FOXO4-DRI been tested in humans?

No published human trials exist; all evidence comes from mice and cells in the lab ¹³.

What did the famous 2017 study show?

In old and fast-aging mice, FOXO4-DRI cleared senescent cells and improved fur, fitness and kidney function ¹.

Is FOXO4-DRI approved?

No. It is an experimental compound with no approval anywhere and is not on FDA's compounding lists ⁶⁷.

Is FOXO4-DRI banned in sport?

It is not named on the 2026 WADA list, but unapproved substances are generally covered by the S0 ban ⁸.

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