Supplied as a finished topical
Skin & Cosmetic
At a glance
Ten answers, each one line. Open any row for the detail behind it.
What it does A fragment of type I collagen that signals to fibroblasts that collagen has been damaged…
A fragment of type I collagen that signals to fibroblasts that collagen has been damaged, prompting them to make more. The palmitoyl tail is what lets it actually get through the skin barrier — a design detail many peptide cosmetics neglect.
Half-life Not applicable — applied topically. The palmitoyl chain drives… — Documented
Not applicable — applied topically. The palmitoyl chain drives partitioning into the stratum corneum; no systemic pharmacokinetics exist.
Typical studied dose Set by the formulation, as a percentage of the finished cream or serum… — On the label
Set by the formulation, as a percentage of the finished cream or serum rather than as an amount taken. The concentration used in the published work is the figure worth comparing a product against.
How often it is used Applied as the product directs, usually once or twice a day. Topical… — On the label
Applied as the product directs, usually once or twice a day. Topical results in the published trials came from months of continuous use, not from a short course.
How it is taken Topical — Documented
Topical
Main side effects Concentration varies widely between products · Industry-funded research · Modest effect sizes — Depends on the study
Concentration varies widely between products — Many products contain far less than the concentrations used in studies.
Industry-funded research — Much of the evidence originates with ingredient suppliers.
Modest effect sizes — Real but incremental; it will not match procedural interventions.
Storage before mixing A finished cream or serum follows its own label — usually cool, dark and…
A finished cream or serum follows its own label — usually cool, dark and sealed. Copper peptides in particular discolour when they degrade, and a colour change is a reason to stop using it.
Shelf life after mixing Nothing to mix — it is not supplied as a powder. The relevant date is…
Nothing to mix — it is not supplied as a powder. The relevant date is the one printed on the product.
Evidence level 3/5 · Moderate — Depends on the study
Small or early-phase human trials, or good controlled topical human data.
Regulatory status Cosmetic Ingredient — Nothing established
Established cosmetic ingredient with published controlled human studies, including a comparison against retinol. Lawful cosmetic ingredient.
Overview
A fragment of type I collagen that signals to fibroblasts that collagen has been damaged, prompting them to make more. The palmitoyl tail is what lets it actually get through the skin barrier — a design detail many peptide cosmetics neglect.
Cosmetic IngredientEstablished cosmetic ingredient with published controlled human studies, including a comparison against retinol.
| Regulatory status | Established cosmetic ingredient with published controlled human studies, including a comparison against retinol. |
|---|---|
| Drug class | Lipidated pentapeptide — a collagen fragment conjugated to palmitic acid |
| Route | Topical |
| Half-life | Not applicable — applied topically. The palmitoyl chain drives partitioning into the stratum corneum; no systemic pharmacokinetics exist. |
| Evidence rating |
3/5 Moderate
Evidence rating 3 out of 5: Moderate
Small or early-phase human trials, or good controlled topical human data. |
| Studied in | A 12-week double-blind split-face trial versus vehicle; a comparative study against retinol; multiple fibroblast and ex-vivo skin studies. |
Matrixyl (Palmitoyl Pentapeptide-4) sequence & structure
Matrixyl (Palmitoyl Pentapeptide-4) is a 5-residue linear peptide with a free C-terminal acid, carrying a fatty-acid side chain; molecular weight 802.07 Da.
| Three-letter | Pal-Lys-Thr-Thr-Lys-Ser-OH |
|---|---|
| Length | 5 amino acid residues |
| Modifications |
|
| Molecular formula | C39H75N7O10 |
| Molecular weight | 802.07 Da (average, free base) |
| SMILES | CCCCCCCCCCCCCCCC(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CO)C(=O)O)[C@@H](C)O)[C@@H](C)O |
| Identifiers | CAS 214047-00-4 · PubChem CID 9897237 · UniProt P02452 |
| Which molecule | Palmitoyl Pentapeptide-4 (current INCI name, since 2006) and Palmitoyl Pentapeptide-3 (older INCI name) are the same molecule, Pal-KTTKS; only the INCI numbering changed. This record describes that single lipopeptide, which is what the pepteyes monograph covers. The unlipidated parent KTTKS (Pentapeptide-4) is a different ingredient, and Sederma's later 'Matrixyl 3000' is a blend of palmitoyl tripeptide-1 (Pal-GHK) and palmitoyl tetrapeptide-7 (Pal-GQPR) that does not contain Pal-KTTKS at all; neither is described here. |
| Sources | PubChem CID 9897237 (Palmitoyl Pentapeptide-4)FDA GSRS / UNII KK181SM5JG (Palmitoyl Pentapeptide-4)ChEMBL CHEMBL451881Katayama et al. 1993, J Biol Chem 268:9941-4 (PMID 8486721)NovoPro Labs product page (cross-check) |
Pal-KTTKS is the N-alpha-palmitoylated form of the pentapeptide KTTKS, which Katayama et al. identified as residues 212-216 of the carboxy-terminal propeptide of the pro-alpha1(I) collagen chain (COL1A1, UniProt P02452); the UniProt accession refers to that precursor, not to the synthetic lipopeptide. FDA GSRS names it 'L-Serine, N2-(1-oxohexadecyl)-L-lysyl-L-threonyl-L-threonyl-L-lysyl-' (acyl on the alpha-amine, free C-terminal acid). PubChem gives MW 802.1, ChEMBL 802.07 and NovoPro 802.05 for the free base; it is often supplied as the acetate salt ('Matrixyl acetate') or as a dilute solution in a glycerin/water carrier, so vendor MW and assay figures may not refer to the neat peptide.
Record confidence: high — two independent authoritative sources agree on the sequence and modifications. Every sequence on the site is listed with its sources on the peptide sequences index.
How it works
The KTTKS sequence is a subfragment of type I procollagen. Applied topically it acts as a feedback signal stimulating fibroblast synthesis of collagen I, collagen III, fibronectin and glycosaminoglycans. Palmitoylation greatly increases lipophilicity and stratum corneum penetration.
Evidence base
Rated 3 of 5 — Moderate. Small or early-phase human trials, or good controlled topical human data.
- Among the best-supported topical cosmetic peptides, with a double-blind vehicle-controlled trial.
Benefits and risks, weighed against the evidence
Every entry below carries the strength of the evidence behind it — three bars for strong human data, two for moderate, one for preliminary or preclinical work. The two columns are not equal by design: where a compound has more documented risk than demonstrated benefit, the lists say so.
Reported benefits
5 entries · 1 on strong human evidence
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Wrinkle and roughness improvement in controlled trials
A 12-week double-blind trial showed significant improvement in wrinkle depth and skin roughness versus vehicle.
Evidence: Moderate evidence -
Comparable to retinol with better tolerance
Comparative work suggests effects approaching retinol's with markedly less irritation.
Evidence: Moderate evidence -
Collagen and matrix stimulation
Consistent fibroblast data showing upregulation of collagen and extracellular matrix components.
Evidence: Moderate evidence -
Designed for skin penetration
The palmitoyl chain solves the delivery problem that limits many topical peptides.
Evidence: Moderate evidence -
Very well tolerated
Suitable for sensitive skin and usable alongside most actives.
Evidence: Strong evidence
Risks and cautions
5 entries
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Modest effect sizes
Real but incremental; it will not match procedural interventions.
Evidence: Minor -
Slow onset
Meaningful changes take 8–12 weeks of consistent use.
Evidence: Minor -
Concentration varies widely between products
Many products contain far less than the concentrations used in studies.
Evidence: Moderate evidence -
Industry-funded research
Much of the evidence originates with ingredient suppliers.
Evidence: Moderate evidence -
Rare contact sensitivity
Uncommon.
Evidence: Minor
Counts are not a score. A single serious risk can outweigh several well-supported benefits, and a long benefit list built on preclinical work outweighs nothing at all.
Opinion — what people actually report
4 themes · 2 reported benefits · 1 reported problem
This is the weakest tier on this site. These are themes drawn from public discussion — forums, subreddits and patient threads — not from trials. There is no control group, no denominator, and no way to confirm that what someone injected matched its label. People post when a result is dramatic and when something goes wrong, and rarely when nothing happens, so treat everything below as a description of the conversation rather than of the compound. The bars count how often a thing is said, not how well it is supported.
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One of the few peptides regulars actually recommend Reported benefit. Dominant theme: Comes up in most discussions of this compound.
Skincare communities treat it as a reasonable, low-risk addition, well tolerated by people who cannot use retinoids.
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Slower and subtler than retinoids Reported problem. Dominant theme: Comes up in most discussions of this compound.
The standard framing — worth using, not a replacement, and requiring months.
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The name means several different things Practical note. Dominant theme: Comes up in most discussions of this compound.
Matrixyl, Matrixyl 3000 and Matrixyl Synthe'6 are different blends, and the naming confusion is a persistent complaint.
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Layers well with almost everything Reported benefit. Recurring: Raised regularly, though not by everyone.
A practical advantage frequently cited over GHK-Cu and vitamin C.
Where the reports and the evidence part ways
This is one of the better-behaved corners of the peptide world. Palmitoyl pentapeptide-4 has controlled human studies showing modest improvements in wrinkle depth and skin roughness, and the community's appraisal — real but modest, slower than retinoids, well tolerated — matches them closely. The main caveats are that the studies are small and largely industry-funded, and that "Matrixyl" on a label does not tell you which blend or what concentration you are getting.
Readers on Matrixyl (Palmitoyl Pentapeptide-4)
Questions and answers from readers, under generated names. Nothing here has been checked or reviewed by the site and none of it is medical advice. It is the least verified thing on this page — and it is here because people ask each other these things anyway, and most of the other places they can ask are run by sellers.
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How names work, and the house rules
Names. Every verified address is given one generated name — two ordinary words — and keeps it. Nobody chooses a name and nobody can take another's. Posts marked desk were written by the site's own editorial desk, usually to open a thread; they carry a generated name like everyone else's and are held to the site's rules, which means they never state an amount.
What is not allowed. Selling, sourcing, vendor names, coupon codes and "message me" — posts that read that way are held and usually removed. Personal medical details you would not want public. Abuse. Instructions framed as what someone else should do.
What this is not. A reader's report of what happened to them is a report, not a finding, and an answer here is one person's view. Nothing in this section changes the evidence rating above it. If something you read here would change what you take, take it to a pharmacist or physician first.
Your data. Delete any post of yours at any time, or remove everything you have written together with your name. Details in the privacy notice.
Who should avoid it
- Known ingredient allergy
If used under medical supervision, monitor
- None required
Regulatory & legal status
Lawful cosmetic ingredient.
Infographic
Where to read further
We link to live literature searches rather than a frozen citation list, so you always see current results — including anything published after our last review.
- PubMed — all published literature on Matrixyl (Palmitoyl Pentapeptide-4)
- PubMed — randomized controlled trials only
- ClinicalTrials.gov — registered human trials
Related peptides in Skin & Cosmetic
Terms used on this page
- Collagen Type I
- Collagen type I is the dominant structural protein of tendon, bone, skin and scar, a triple-helical heterotrimer whose thick cross-linked fibrils carry tensile load.
- Skin Barrier Function
- Skin barrier function is the stratum corneum's capacity to restrict water loss outward and chemical entry inward, sustained by corneocytes embedded in ordered intercellular lipid lamellae.
- Fibroblast
- A fibroblast is the mesenchymal cell that produces and maintains connective tissue matrix, and which differentiates into a contractile myofibroblast during wound repair.
- Glycosaminoglycans (GAGs)
- Glycosaminoglycans are long unbranched sugar chains of repeating disaccharides that hold water in the dermal ground substance and, except for hyaluronan, are sulfated and attached to core proteins.
- Stratum Corneum
- The stratum corneum is the outermost epidermal layer of dead, keratin-filled corneocytes in a lipid matrix, and it is the rate-limiting barrier for essentially every topical ingredient.
- Lipidation and Fatty Acid Acylation
- Lipidation is the covalent attachment of a fatty acid to a peptide, usually at a lysine side chain, creating reversible albumin binding that dramatically extends circulating half-life.
This page is educational information, not medical advice. It cannot account for your medical history, medications, or risk factors. Do not start, stop or change any treatment based on it. Speak to a qualified healthcare professional who knows your case.