Palmitoyl tripeptide-5 turns up in serums, eye patches and moisturisers sold on collagen claims, often among several other peptides. Its supplier name is Syn-Coll, and the story attached to it is that it imitates a natural protein that switches on collagen production. This page checks the molecule, the mechanism and the published evidence. It is an ingredient file, not a product recommendation.
The molecule, under three names
| Name | Where it appears |
|---|---|
| Palmitoyl tripeptide-5 | Ingredient lists (INCI) |
| Syn-Coll | Supplier trade name |
| Pal-Lys-Val-Lys (Pal-KVK) | Chemistry and research papers |
PubChem records all three under one entry, CID 11950477: formula C33H65N5O5, molecular weight 611.9 g/mol, CAS number 623172-55-4. The peptide part is just three amino acids — lysine, valine, lysine. The rest is a palmitoyl group, a 16-carbon fatty acid attached to the first lysine to make the molecule more oil-friendly, the same trick used for Matrixyl and palmitoyl tripeptide-1.
The fatty tail is also why its weight sits just above the rough 500-dalton line dermatologists use as a guide to what crosses intact skin. That line is a rule of thumb, not a wall, and lipid tails are added precisely to help peptides into the skin's oily outer layer; but no study we found measured how much palmitoyl tripeptide-5 reaches living human skin from a finished product.
The mechanism, and a sequence that does not match
The claim runs like this. Thrombospondin-1 is a large protein in the tissue between cells. Part of its job is to activate TGF-beta, a growth factor that is stored in an inactive form and, once released, tells fibroblasts to make collagen. A 2021 review describes palmitoyl tripeptide-5 as "a fragment of Thrombospondin I", said to promote type I collagen synthesis and reduce the enzymes that break collagen down (Resende 2021, Pharmaceuticals, PMID 34451799, citing supplier and patent sources).
The laboratory that mapped how thrombospondin-1 activates TGF-beta identified the working sequence precisely: K412-R-F-K415, "KRFK", which binds a matching sequence (LSKL) on the inactive TGF-beta complex (Ribeiro 1999, Journal of Biological Chemistry, PMID 10224129). KRFK has since been tested on its own as a TGF-beta-activating peptide, for example on the eye surface in mice (Soriano-Romaní 2018, PMID 30577496).
Palmitoyl tripeptide-5 is K-V-K. It shares the two lysines at the ends of the activating sequence and replaces the arginine-phenylalanine middle with a single valine. So "a fragment of thrombospondin" overstates it; at most it is a short analogue designed around that sequence. Whether K-V-K activates TGF-beta the way KRFK does is an empirical question, and none of the five indexed papers on palmitoyl tripeptide-5 reports a TGF-beta activation measurement in its abstract. The supplier's own technical page, which would state the claim in its own words, did not load for us on 28 September 2026.
Five papers, counted
On 28 September 2026, Europe PMC's copy of MEDLINE held 5 records naming palmitoyl tripeptide-5, Syn-Coll or Pal-KVK in the title or abstract. As a check that the search works, the same query for acetyl hexapeptide-8 or Argireline returned 39. Searching full texts and patents as well lifts the count to 45, most of which mention the peptide in passing inside a list of ingredients.
| Record | What it is | What it tested |
|---|---|---|
| Avcil 2020, J Cosmet Dermatol (PMID 31134751) | Monocentric 12-week study with volunteers | A hyaluronic-acid microneedle patch containing five actives: arginine/lysine polypeptide, acetyl octapeptide-3, palmitoyl tripeptide-5, adenosine and seaweed extracts. Fine lines down 25.8%, hydration up 15.4%; no product without the peptide |
| Resende 2021, Pharmaceuticals (PMID 34451799) | Market and literature review | Peptides in 88 sensitive-skin facial products; no efficacy study of palmitoyl tripeptide-5 found |
| Shariati Pour 2023, Molecules (PMID 36985499) | Formulation study | Loading the peptide into a self-healing gel; no skin outcome |
| Chen 2025, Colloids Surf B (PMID 39383579) | Formulation plus volunteer measurements | Nanoparticles of lactoferrin, recombinant collagen and palmitoyl tripeptide-5; reported hydration, elasticity and wrinkle changes over 28 days; no peptide-free comparison in the abstract |
| Xiong 2026, J Control Release (PMID 41344485) | Formulation plus consumer evaluation | Pal-KVK self-assembled into a hydrogel mask; "consumer dermatological evaluations" reported anti-wrinkle and moisturising effects |
Every result with people in it comes from a mixture or a new delivery system, and none compares the same formula with and without the peptide. That is the difference between "products containing palmitoyl tripeptide-5 were associated with improvement" and "palmitoyl tripeptide-5 improves skin". Only the first is supported.
The sensitive-skin claim
Palmitoyl tripeptide-5 is also sold into products for sensitive and redness-prone skin. Resende and colleagues analysed 88 facial cosmetics for sensitive skin from multinational brands and found peptides in 17% of them; palmitoyl tripeptide-5 was the fourth most used. It had appeared in a supplier's ingredient mix aimed at redness in type I rosacea that, by 2021, was no longer available. The authors' conclusion is plain: "neither efficacy studies for the use of palmitoyl tripeptide-5 alone or in this mix in rosacea of sensitive skin are available", and most of what is known about these peptides sits "in patents and supplier brochures". Our peptides for rosacea page covers what the wider evidence on peptides and redness holds.
Where it appears on labels
Palmitoyl tripeptide-5 is a common member of multi-peptide blends. On this site's ingredient analyses it is the first of nine peptides Medik8 names for its Liquid Peptides serum, it sits at position 10 of 48 in Naturium's Multi-Peptide Moisturizer, and at position 34 of 41 on the COSRX peptide collagen eye patch, in the final quarter of the list. Patches like that one are compared with the microneedle patches the trials used on our peptide eye patches page. As our peptide serum page explains, below the 1% line a peptide's position does not reveal its amount. It also sits at position 9 of 50, in a run of seven peptides, on ALASTIN Restorative Skin Complex.
What this supports saying
- Palmitoyl tripeptide-5 is a real, well-characterised molecule: Pal-Lys-Val-Lys, 611.9 daltons, sold as Syn-Coll.
- Its collagen mechanism is borrowed from thrombospondin-1's KRFK sequence, which it resembles but does not reproduce, and no indexed paper we found measured the borrowed mechanism for this peptide.
- It has no human trial of its own. The three studies with volunteers all tested mixtures without a peptide-free control.
- The evidence file is about the same size as its neighbours' — see pentapeptide-18 and palmitoyl tripeptide-1 — and far smaller than retinoids'. Our what peptides do for skin page sets out what the whole signal-peptide class has and has not shown.
Sources
- PubChem compound record CID 11950477 (palmitoyl tripeptide-5), synonyms and properties via PUG REST, 28 September 2026.
- Ribeiro SM, Poczatek M, Schultz-Cherry S, Villain M, Murphy-Ullrich JE. The activation sequence of thrombospondin-1 interacts with the latency-associated peptide to regulate activation of latent TGF-beta. J Biol Chem 1999. PMID 10224129.
- Soriano-Romaní L, et al. Topical Application of TGF-β-Activating Peptide, KRFK, Prevents Inflammatory Manifestations in the TSP-1-Deficient Mouse. Int J Mol Sci 2018. PMID 30577496.
- Resende DISP, et al. Usage of Synthetic Peptides in Cosmetics for Sensitive Skin. Pharmaceuticals 2021. PMID 34451799 (full text read).
- Avcil M, et al. Efficacy of bioactive peptides loaded on hyaluronic acid microneedle patches. J Cosmet Dermatol 2020. PMID 31134751.
- Shariati Pour SR, et al. Delivery of Active Peptides by Self-Healing, Biocompatible and Supramolecular Hydrogels. Molecules 2023. PMID 36985499.
- Chen W, et al. Supramolecular collagen nanoparticles for anti-wrinkle, skin whitening, and moisturizing effects. Colloids Surf B 2025. PMID 39383579.
- Xiong Y, et al. Lipidated peptide nanostructures for stabilizing hydrogels with sustained skincare bioactivity. J Control Release 2026. PMID 41344485.
- Europe PMC searches (MEDLINE title/abstract; all sources), 28 September 2026.