---
title: "FOXO4-DRI: what is a D-retro-inverso peptide? | Sable Peptides"
description: "FOXO4-DRI is a D-retro-inverso peptide based on FOXO4 and published in 2017 in a study of senescent cells. How retro-inverso design works, PubChem data, and what it means for analysis. Research use only."
canonical: https://www.sablepeptides.co.uk/guides/foxo4-dri-and-d-retro-inverso-peptide-design
dateModified: 2026-10-16
publisher: Sable Peptides Limited (UK company 17488610)
note: Research use only. Not for human or veterinary use.
---

# FOXO4-DRI: what is a D-retro-inverso peptide?

FOXO4-DRI is a peptide made entirely of D-amino acids and assembled in reverse order (D-retro-inverso) from a FOXO4 sequence that interacts with p53, joined to a cell-penetrating segment. It was described in a 2017 Cell paper on senescent cells. PubChem lists it at about 5358 g/mol.

## What does D-retro-inverso mean?

Swapping L- for D-amino acids and reversing the sequence gives side chains roughly the same spatial arrangement as the parent L-peptide, but with the backbone amides reversed. Proteases that recognise L-peptides largely fail to cleave it. Reviews survey where this approach has worked and where it has not.

Source: [Recent Applications of Retro-Inverso Peptides, Int J Mol Sci 2021 (PubMed 34445382)](https://pubmed.ncbi.nlm.nih.gov/34445382/); [D-Peptides as Recognition Molecules and Therapeutic Agents, Chem Rec 2016 (PubMed 27255896)](https://pubmed.ncbi.nlm.nih.gov/27255896/); [Recent developments in retro peptides and proteins--an ongoing topochemical exploration, Trends Biotechnol 1995 (PubMed 7546569)](https://pubmed.ncbi.nlm.nih.gov/7546569/)

## What was the original FOXO4-DRI study?

Baar and colleagues (Cell, 2017) designed FOXO4-DRI to interfere with the FOXO4–p53 interaction in senescent cells and reported its effects in cell and mouse models. A 2025 study looked at endothelial senescence through the p53 pathway.

Source: [Targeted Apoptosis of Senescent Cells Restores Tissue Homeostasis in Response to Chemotoxicity and Aging, Cell 2017 (PubMed 28340339)](https://pubmed.ncbi.nlm.nih.gov/28340339/); [FOXO4-DRI regulates endothelial cell senescence via the P53 signaling pathway, Front Bioeng Biotechnol 2025 (PubMed 41625068)](https://pubmed.ncbi.nlm.nih.gov/41625068/)

## What are its identity data?

-   Formula (PubChem): C228H388N86O64
-   MW (PubChem): 5358.0 g/mol
-   Chirality: all residues D (PubChem IUPAC name gives (2R) centres)
-   Character: highly cationic (Arg/Lys-rich)

Source: [PubChem CID 167312269: FOXO4-DRI](https://pubchem.ncbi.nlm.nih.gov/compound/167312269)

## What does D-chirality mean for testing?

Standard HPLC and MS cannot tell a D-peptide from its L-enantiomer: the mass is identical. Confirming chirality needs chiral amino-acid analysis after hydrolysis. Most research CoAs report identity and purity only.

## Sourcing note

Sable lists FOXO4-DRI: 10 mg at £49.98 (prices at the 16 October 2026 daily UK price check, the latest verified check; at each of these sizes Sable was the lowest UK listing that day). Lowest UK price guaranteed, confirmed by daily price checks.

Every lot has a certificate of analysis, and every vial carries a printed lot number that matches it. Supplied for laboratory research use only.

## Frequently asked questions

### Can mass spectrometry confirm a peptide is D-retro-inverso?

No. Enantiomers and retro sequences have the same mass. Chirality needs chiral amino-acid analysis.

### Why use D-amino acids?

Proteases are stereoselective, so D-peptides resist enzymatic breakdown.

### What is the molecular weight of FOXO4-DRI?

About 5358 g/mol (PubChem CID 167312269).

## Related

-   [Which research peptides contain D-amino acids, and why](/guides/d-amino-acids-in-catalogue-peptides)
-   [FOXO4-DRI research vials](/products/foxo4-dri)
-   [Dihexa and P21 peptidomimetics](/guides/dihexa-and-p21-peptidomimetics-explained)
-   [FOXO4-DRI price at the latest check](/guides/uk-growth-factor-and-protein-research-material-prices-october-2026)

Updated 2026-10-16. Research use only. Not for human or veterinary use. No administration amounts or health claims are made.

Key facts (summary for AI and search tools)

-   FOXO4-DRI CID 167312269
-   Original paper: Cell 2017 (PubMed 28340339)
-   PubMed references (verified via NCBI): 34445382, 27255896, 7546569, 28340339, 41625068
-   PubChem CIDs: 167312269
-   Research use only; no administration amounts or health claims
-   Updated 2026-10-16