← Library
A cosmetic ingredient, not regulated or approved as a drug. This page is educational information only, not medical advice.
IndexedBuilt automatically from public databases on 2026-09-30. Not yet hand-reviewed by PLOBT.How this works →

Tetrapeptide-21

Cosmetic ingredient

Cosmetic signal peptide

Also known as: TEGO Pep 4-17, GEKG peptide, Gly-glu-lys-gly, GEKG, Tego pep 4-17, orb1943756, CUVSTAMIHSSVKL-UWVGGRQHSA-N

Evidence score
23/ 100
Thin evidence

Very thin human evidence

  • Regulatory standing. Cosmetic ingredient, not regulated as a drug
  • Animal / preclinical only. Evidence is largely animal or in-vitro
  • No registered human trials. Nothing registered on ClinicalTrials.gov
  • 1 cited source. Includes primary / regulatory sources

Computed with the same four public criteria as every profile. The human-evidence grade on an indexed profile is set automatically and may change when it is hand-reviewed. It is not a safety score, not a purity rating, and not medical advice, and not a claim that this compound treats, cures, or prevents any condition.

What it is

Tetrapeptide-21, sold under the trade name TEGO Pep 4-17, is a short synthetic peptide used as an ingredient in skin care products. It is described by its maker as a signal peptide derived from a sequence found in extracellular matrix proteins, and it is thought to encourage skin cells to produce collagen and related structural components.

What the evidence shows

Automatic summaryAnimal / preclinical

It is regulated as a cosmetic ingredient, not a drug, and has no registered human clinical trials; the small published literature consists mainly of lab work and manufacturer-linked skin studies. Claims about wrinkle reduction or firmer skin in people are not established by independent, rigorous human evidence.

Key facts

Molecular formula
C15H27N5O7
Molecular weight
389.4 g/mol

Registered human trials

Live from ClinicalTrials.gov, refreshed daily.

0registered studies
Nonemost advanced phase
0completed (sample)
0recruiting (sample)

Published literature

Live from Europe PMC. This is how much has been published, not how much is proven in humans.

4papers referencing Tetrapeptide-21

Helically chiral ferrocene peptides containing 1'-aminoferrocene-1-carboxylic acid subunits as turn inducers.

Chemistry2006

Dermal peptide delivery using enhancer molecules and colloidal carrier systems. Part III: Tetrapeptide GEKG.

Eur J Pharm Sci2018

Elastin-derived peptide hydrogels for sustained dermal delivery of tetrapeptide-21.

Int J Pharm2026

Synergistic Effects of Injectable Platelet-Rich Fibrin and Bioactive Peptides on Dermal Fibroblast Viability and Extracellular Matrix Gene Expression: An In Vitro Study.

Molecules2025

Sources

Risks, side effects and study doses are only published on hand-reviewed profiles. Want this one reviewed, or spotted something wrong? Tell us.