Tripeptide-1

Tripeptide-1 is the free-base form of Gly-His-Lys, the collagen-derived fragment that becomes GHK-Cu once copper is bound. Applied without copper, it retains matrikine signalling to fibroblasts for collagen and glycosaminoglycan production, and because its affinity for copper(II) is high it will scavenge copper from the skin's own pool and partially reconstitute the active complex in situ. That last step is the reason it is not simply an inferior product — but it does depend on there being copper available locally, which makes the effect less predictable than dosing the complex directly. Practically, formulators reach for it when they want GHK signalling in a product that also contains L-ascorbic acid, retinaldehyde or another reducing active that would destroy a preformed copper complex, or when they want to avoid the blue colour.

Targets: Dermal fibroblasts, Collagen and glycosaminoglycan synthesis, Endogenous copper(II) binding

• · 0.1-1% w/w, the same range as the copper complex. 200 mg into 20 mL gives 1%.

Work out your exact syringe units →

• rareIrritation— Better tolerated than the copper form, which is part of the appeal.

• redundantghk-cu-topical — Same peptide; the copper form is the more studied of the two.
• synergyl-ascorbic-acid — The main reason to choose this form — no copper to be reduced and destroyed.
• redundantpalmitoyl-tripeptide-1 — Same backbone, lipidated for better penetration.

• · Standardised photography at 0, 8 and 16 weeks.

Cosmetic ingredient (INCI Tripeptide-1) approved worldwide.

• Pickart & Margolina 2018, regenerative and protective actions of GHK-Cu (Int J Mol Sci) (review)

The pharmacologically interesting property of free GHK is that it is not really a copper-free molecule — it is a copper-seeking one. Its affinity for Cu(II) is high enough that it will strip copper from weaker ligands and, crucially, is close enough to that of albumin and histidine that it exchanges rather than sequesters. Skin contains copper. So applying free GHK to skin is applying a chelator into a copper-containing tissue, and the expectation is that it picks up copper locally and partially reconstitutes an active GHK-Cu complex in situ. If that is what happens, Tripeptide-1 is a prodrug and the distinction from GHK-Cu is mostly formulation convenience. If it is not what happens — if local exchangeable copper is scarce, or if the peptide is degraded before it finds any — then Tripeptide-1 is a matrikine without the copper-dependent half of the biology, which is the more interesting half. Nobody has done the experiment. That is the central unknown for this ingredient and it should not be papered over. Independent of copper, the matrikine arm survives: GHK signals fibroblast collagen and glycosaminoglycan production in culture. What formulators actually use it for is more prosaic and more defensible: it is colourless, so no blue staining, and it has no preformed copper to be reduced, so it can sit in a product alongside L-ascorbic acid, retinaldehyde or another reducing active that would destroy the copper complex.

The main error is assuming the GHK-Cu literature transfers. It does not automatically, and the specific parts that make GHK-Cu interesting — antioxidant enzyme induction, wound healing acceleration, the copper-responsive transcriptional programme — are the copper-dependent parts. Buying Tripeptide-1 and citing Pickart is a category slip. The second is formulation stability: unprotected termini and no copper stabilisation mean free GHK is the most labile GHK product, so an unpreserved aqueous solution is genuinely a thirty-day product. The third, and this is a small but real one, is water quality in DIY: use deionised or distilled water, because tap water contains enough copper to turn your colourless serum blue and, more to the point, to consume peptide.

• Copper(II) — as an acquiring ligand — Log K around 16 at physiological pH, comparable to albumin and histidine so exchange is facile

  Scavenges endogenous copper and may reconstitute an active complex in skin. This is the central unproven mechanism.

• Unidentified fibroblast matrikine receptor — No receptor cloned

  Collagen and glycosaminoglycan synthesis, independent of copper.

Week 8-12 for the first visible change, week 16-24 for a fair assessment — the same as the copper form, on the assumption that the mechanism is the same. There is no human timeline data specific to the copper-free form.

The entire reason to choose this form is chemical compatibility, so use it for that. Free GHK layers with L-ascorbic acid, with retinaldehyde, with ferulic acid and with anything else reducing, because there is no preformed copper complex to be destroyed. It also does not stain. If neither of those matters to you, use GHK-Cu, because that is what almost every published study actually used. Do not stack Tripeptide-1 with GHK-Cu or with palmitoyl tripeptide-1 — same backbone, three delivery strategies, one effect. One caution worth knowing: because free GHK is a copper chelator, in a formulation containing trace copper from water or equipment it will turn blue, and formulators occasionally panic about that. It is the complex forming, not contamination in any meaningful sense.

Against GHK-Cu: identical backbone, no copper, no blue stain, no vitamin C conflict, and none of the copper-dependent biology unless the in-situ reconstitution hypothesis is correct. Almost all published GHK research used the copper complex, so on evidence, GHK-Cu wins clearly. Against palmitoyl tripeptide-1: the palmitoylated version penetrates better but has its copper site permanently blocked by the acyl group, whereas free GHK keeps its site available — so free GHK has the better chemistry and worse delivery. The rational selection rule is simple: choose GHK-Cu unless a formulation conflict prevents it, then choose this.

$6–$45/month. Raw GHK is the cheapest peptide in this class at roughly $15-40 per gram, and one gram at 1% makes 100 mL of serum. Finished products $12-45 a month. Market observation, not a sourced pricing study.

• ?Whether free GHK actually acquires enough endogenous copper in skin to reconstitute an active complex is the central open question and has never been tested.
• ?Essentially no clinical data exist for the copper-free form specifically. It inherits its rationale from the copper complex.
• ?No permeation data quantify how much free GHK reaches viable skin.
• ?The molecular weight of 340.4 Da is the standard published figure for free GHK; vendor material is often an acetate or trifluoroacetate salt with a different assay mass.
• ?Whether the matrikine signalling arm is copper-independent at all, or whether every reported GHK effect requires copper, is not clearly established in the literature.

• Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data Pickart L, Margolina A, International Journal of Molecular Sciences, 2018 · PMID 29986520

  The reference review. Read it aware that essentially all of it is about the copper complex, not the free peptide sold as Tripeptide-1.

• Topically applied GHK as an anti-wrinkle peptide: Advantages, problems and prospective Mortazavi SM, Mohammadi Vadoud SA, Moghimi HR, BioImpacts, 2025 · PMID 39963574

  Specifically about topically applied GHK rather than GHK-Cu, and honest about the delivery problem. The most directly relevant paper for this entry.

• The human tripeptide GHK-Cu in prevention of oxidative stress and degenerative conditions of aging: implications for cognitive health Pickart L, Vasquez-Soltero JM, Margolina A, Oxidative Medicine and Cellular Longevity, 2012 · PMID 22666519

  Background on the copper-handling chemistry that determines whether the free peptide behaves as a prodrug.

• Are We Ready to Measure Skin Permeation of Modern Antiaging GHK-Cu Tripeptide Encapsulated in Liposomes? Ogórek K, Nowak K, Wadych E, Ruzik L, Timerbaev AR, Matczuk M, Molecules, 2025 · PMID 39795193

  The analytical state of the art on measuring GHK skin permeation, which is still unsettled.