Longevity & Cellular Health

Tetrapeptide-30

Tetrapeptide-30 is four amino acids — proline, lysine, glutamate, lysine, usually abbreviated PKEK — applied to skin to even out tone. Its proposed mechanism is upstream rather than bleaching: it suppresses the ultraviolet-B-driven signals, including proopiomelanocortin and the enzyme tyrosinase, that tell skin cells to make pigment in the first place. Its graded evidence is entirely in silico, both citations being computer predictions, a safety model and an ecotoxicity estimate, with no laboratory measurement among them. A vehicle-controlled study in South Africa did report better skin tone at twelve weeks, though the widely quoted pigment-fading result comes from PKEK paired with a vitamin C derivative, so it belongs to the pair.

Last updated 12 August 2026

Studied forHyperpigmentation research · Skin tone evenness · UV response context

Evidence on file2 computational studies · 1 citation not yet graded

Strongest sourceA framework for the safety evaluation of peptides in cosmetics. (computational study)

Mechanism

Suppresses UVB-induced expression of inflammatory cytokines, proopiomelanocortin, and tyrosinase, reducing melanin production.

Reported effects

What sources associate with this compound. Reported categories, not outcomes we have graded — each would need its own citation and rung.

Hyperpigmentation research
Skin tone evenness
UV response context

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 claim (SpecialChem/Evonik datasheet): "an anti-aging, anti-inflammatory and brightening agent" that "contributes to an even skin tone and leads to a visible fading of the hyperchromatic spots", "brightens the skin", "reduces acne lesions and alleviates melasma on ethnic skin". ci.guide adds it "helps to relieve melasma and/or post-inflammatory hyperpigmentation or acne lesions". No n= or duration on fetched pages.

Manufacturer: Evonik
Sold as: TEGO Pep 4-Even (TEGO Pep 4-Even MB)

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

Dosing on file unverified

No established human dose; cosmetic serum concentrations vary

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 5

review or editorial
Peptides: Emerging Candidates for the Prevention and Treatment of Skin Senescence: A Review. graded on: indexed as "review-article" - secondary literature, not a study — “review-article”
review or editorial
Topical Treatments for Melasma and Their Mechanism of Action. graded on: indexed as "review-article" - secondary literature, not a study — “review-article”
computational
A framework for the safety evaluation of peptides in cosmetics. graded on: in-silico safety framework applied through six bioinformatic tools — read from the abstract — “abstract review”
computational
Usage Frequency and Ecotoxicity of Skin Depigmenting Agents. graded on: a computational prediction — read from the indexed abstract — “in silico”

Not graded

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

not graded
MANUFACTURER_DATA_ONLY

Identity

Space-filling 3D model of Tetrapeptide-30, carbon grey, nitrogen blue, oxygen red — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

2D chemical structure of Tetrapeptide-30 — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

Molecular weight: 500.6
Molecular formula: C22H40N6O7
CAS number: 1036207-61-0
PubChem CID: 25001762
InChI key: LYHZXMVNRVAAJA-QAETUUGQSA-N
SMILES: C1C[C@H](NC1)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CCCCN)C(=O)O
InChI: InChI=1S/C22H40N6O7/c23-11-3-1-6-15(26-19(31)14-8-5-13-25-14)20(32)27-16(9-10-18(29)30)21(33)28-17(22(34)35)7-2-4-12-24/h14-17,25H,1-13,23-24H2,(H,26,31)(H,27,32)(H,28,33)(H,29,30)(H,34,35)/t14-,15-,16-,17-/m0/s1

Also called

TEGO Pep 4-Even
Tetrapeptide-30

Notes unverified prose

Topical cosmetic studies only

Not on file 2

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

amino-acid sequencenothing we hold supplies it
half-lifenothing we hold supplies it

Each field links to every other record missing the same thing. The full ledger holds 765 gaps across 163 records.