FOXO4-DRI dosage: why nobody can give you a number
A dose is not a figure somebody has used. It is the output of a process: phase 1 trials establishing how a compound behaves in humans and where tolerability breaks down, then phase 2 finding where benefit appears, then a regulator reviewing all of it and approving a label.
FOXO4-DRI has completed none of those stages. There is no measured human half-life, no bioavailability figure, no clearance route, no maximum tolerated dose and no adverse-event dataset.
That includes clinics. A longevity practice quoting a FOXO4-DRI dose is not drawing on data a consumer lacks access to, because no such data exists anywhere. They are extrapolating from the same mouse papers, in a setting that lends the number unearned authority.
| Requirement | Status for FOXO4-DRI |
|---|---|
| Phase 1 tolerability data | Never collected |
| Human half-life | Never measured |
| Bioavailability | Never measured |
| Maximum tolerated dose | Never established |
| Regulatory review | Never conducted |
| Approved label | Does not exist |
What a dose requires, and what exists
What the mouse studies actually used
The foundational 2017 study reports its dosing explicitly, so it can be described rather than guessed at.
Mice received FOXO4-DRI at 5 mg/kg, three times on alternating days, days 1, 3 and 5. Administration was intravenous in the chemotoxicity experiments and intraperitoneal in the ageing cohorts. Doxorubicin, used to drive cells into senescence in that model, was given separately at 10 mg/kg in mice.
Two things are consistently misreported. The schedule was intermittent, three doses across five days rather than a course. And both routes are laboratory routes; intraperitoneal injection has no routine human application.
Why the mouse figure cannot be converted
The obvious move is to multiply by body weight and apply a scaling factor. Allometric scaling is a real method, but it estimates a starting point for formal study rather than producing a usable dose, and it needs inputs that do not exist here.
Scaling assumes you know how a compound is absorbed, distributed, metabolised and cleared in the target species. For this peptide in humans, none of those has been measured.
The construction complicates it further. FOXO4-DRI is built to resist protease degradation, which should extend its persistence relative to an ordinary peptide, and by how much in a human body has never been determined.
The problem that exists before any dose question
Even in a laboratory, the arithmetic starts from a mass, and for this product the label and the assays disagree.
Kovera Labs measured 11.41 mg on batch 55-05260628. MZ Biolabs measured 8.30 mg on lot 55-01260229. Both vials were labelled 10 mg, and both tested above 99% pure, because purity and quantity are separate measurements.
Anyone calculating a concentration from the label while holding the January batch is working roughly 17% below what they recorded. No care downstream corrects an incorrect starting mass.
For what goes wrong in this arithmetic more generally, see our work on dosing errors.
| Starting mass | In 1 mL | In 2 mL | In 3 mL |
|---|---|---|---|
| 10 mg, label | 10.00 mg/mL | 5.00 mg/mL | 3.33 mg/mL |
| 11.41 mg, Kovera | 11.41 mg/mL | 5.71 mg/mL | 3.80 mg/mL |
| 8.30 mg, MZ Biolabs | 8.30 mg/mL | 4.15 mg/mL | 2.77 mg/mL |
Concentration by starting mass