Tissue Repair & Regeneration

Tetrapeptide-21

Last updated 12 August 2026

Evidence on file1 in-vitro study · 3 citations not yet graded

Strongest sourceSynergistic Effects of Injectable Platelet-Rich Fibrin and Bioactive Peptides on Dermal Fibroblast Viability… (in-vitro study)

Manufacturer’s claim vendor marketing

For a proprietary cosmetic ingredient the manufacturer is the originator — there is no upstream to defer to, and this is often the only description that exists. It is reproduced as an attributed claim, with the label its source gave it. It is not graded and it is not evidence — the graded studies are under Literature.

Vendor claims quoted from incidecoder: "superior collagen, hyaluronic acid and fibronectin boosting activity"; in vitro "collagen production in the presence of Tetrapeptide-21 was almost 2-fold higher" vs Matrixyl; in vivo (n=60, 8 weeks) "Tetrapeptide-21 performed better after 8 weeks for skin volume, roughness and elasticity" vs Matrixyl; 60-person 4% study showed "visible-to-the-naked-eye wrinkle reduction around the eye area".

Manufacturer: Not confirmed on fetched pages (TEGO is widely associated with Evonik, but the Evonik product URL redirected to a generic page and no fetched page named the owner)
Sold as: TEGO Pep 4-17
Manufacturer’s recommended use: Tested at 0.5%, 4% and 5% per incidecoder; no official recommendation stated

Source page — nofollow, because a vendor link is a reference here, not an endorsement.

Dosing on file unverified

0.01-0.05% cream; 10-100 ppm, 2x/day (8 weeks)

Carried from a source that labels it unverified, and reproduced with that label attached. A record of what is reported, not a recommendation. No citation on this page establishes it.

Literature on file 4

in vitro
Synergistic Effects of Injectable Platelet-Rich Fibrin and Bioactive Peptides on Dermal Fibroblast Viability and Extracellular Matrix Gene Expression: An In Vitro Study. graded on: an in-vitro system — “In Vitro”

Not graded

3 citations whose study design could not be read from the title. Left ungraded rather than guessed at.

Identity

Space-filling 3D model of Tetrapeptide-21, carbon grey, nitrogen blue, oxygen red — Built from the SMILES on this record — the atoms, bonds and stereochemistry are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

2D chemical structure of Tetrapeptide-21 — Built from the SMILES on this record — the atoms, bonds and stereochemistry are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

Molecular weight: 389.40
Molecular formula: C15H27N5O7
CAS number: 960608-17-7
PubChem CID: 42630677
InChI key: CUVSTAMIHSSVKL-UWVGGRQHSA-N
SMILES: C(CCN)C[C@@H](C(=O)NCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)CN
InChI: InChI=1S/C15H27N5O7/c16-6-2-1-3-9(14(26)18-8-13(24)25)20-15(27)10(4-5-12(22)23)19-11(21)7-17/h9-10H,1-8,16-17H2,(H,18,26)(H,19,21)(H,20,27)(H,22,23)(H,24,25)/t9-,10-/m0/s1

Also called

TEGO Pep 4-17
Tetrapeptide-21

Notes unverified prose

8-week in vivo study (n=60): outperformed Matrixyl for skin volume, roughness, elasticity; 0.05%: nasolabial fold depth -19%; In vivo study (n=60, 8 weeks) outperformed Matrixyl

Not on file 1

1 of the 8 fields we track hold nothing on this record, and each says why. A blank field is a bug; a named absence is a finding.

amino-acid sequencenothing we hold supplies it

Each field links to every other record missing the same thing. The full ledger holds 521 gaps across 136 records.