GHK (Tripeptide-1 / GHK Basic)

1 Identity

Synthetic tripeptide, constitutionally identical to an endogenous human plasma tripeptide. Metal-free. Sold both as a cosmetic raw material and as a research chemical. and CAS 49557-75-7 as commonly published. vendor shorthand "GHK basic".

Sequence

H-Gly-L-His-L-Lys-OH; one-letter GHK. Three residues, all proteinogenic, both chiral centers L. Free N-terminal alpha-amine on glycine, free C-terminal carboxylic acid on lysine, free lysine epsilon-amine, free histidine imidazole. No amidation, no acetylation, no acylation, no lipidation, no PEGylation, no disulfide (there is no cysteine), no non-proteinogenic residue and — the defining negative for this record — no metal. The three free nitrogen donors that make this molecule a good copper ligand are present and unoccupied; that is a property of the ligand and is precisely why an uncomplexed lot and a complexed lot are two different articles. Supplied as the free base or as an acetate salt; the salt form is stated per lot rather than assumed.

Molecular formula

C14H24N6O4 (free base, C-terminal free acid). Acetate salt C14H24N6O4 . C2H4O2 = C16H28N6O6.

Average mass

340.384 Da for C14H24N6O4 on IUPAC 2021 abridged conventional atomic weights. Listings commonly print 340.38 and reference material approximately 340.4; the formula gives 340.384. Acetate salt 400.44 Da (C16H28N6O6).

Monoisotopic mass

340.1859 Da neutral. [M+H]+ 341.1932; [M+2H]2+ 171.1002; [M-H]- 339.1786. Acetate salt 400.2070 neutral.

Salt / variant note

(1) the copper complex, which is A different article on the same shelf. GHK-Cu, C14H22CuN6O4, 401.91 average / 401.100 monoisotopic (63Cu isotopologue), CAS 89030-95-5 — plus 61.53 Da on the free ligand, blue to blue-violet where this article is white, and carrying a copper isotope envelope this article does not have. (2) GHK-Cu mono-acetate, C16H26CuN6O6, 461.97 / 461.121, CAS 300801-03-0 — what one institutional supplier actually ships under the name GHK-Cu. (3) Prezatide copper acetate, C30H48CuN12O10, 800.33 / 799.291, CAS 130120-57-9 — a 2:1 GHK:Cu bis-complex and a different stoichiometry entirely. (4) GHK acetate salt, C16H28N6O6, 400.44 / 400.207 — the ordinary salt form of this article, +60.05 Da, and a number routinely quoted as though it were the peptide's molecular weight. (5) AHK, C15H26N6O4, 354.41 / 354.202, exactly +14.03 Da, and its complex AHK-Cu C15H24CuN6O4 415.94 / 415.116; at least one market reference publishes AHK-Cu under the page heading "Copper Tripeptide-1", which is GHK-Cu's INCI name, so these names are already crossed in print. (6) Palmitoyl tripeptide-1 (pal-GHK), C30H54N6O5, 578.80 / 578.416, +238.42 Da. (7) N-acetyl-GHK, C16H26N6O5, 382.42 / 382.196, +42.01 Da — the incomplete-deprotection or over-acylation residue. (8) GHK C-terminal amide, C14H25N7O3, 339.40 / 339.202, -0.98 Da, inside any tolerance stated in whole daltons. (9) the substitutions no mass measurement can reach. The sequence permutations KHG, HGK, GKH, KGH and HKG all have formula C14H24N6O4 and are isobaric with GHK to every decimal place; and [D-His2]-GHK and [D-Lys3]-GHK are likewise exactly isobaric and co-elute on achiral reversed-phase columns. Only MS/MS sequencing addresses the first class and only a chiral method addresses the second.

2 Class & testing panel

Form

Single article

Testing panel

P1 — panel definitionTwo things sit on the panel for this article in particular. Copper is a release attribute and is reported as a negative result against a numeric limit, with an express statement that copper is not an intentional constituent — the mirror image of the requirement carried on the copper complex. And MS/MS sequencing is a first-lot requirement rather than an option, because the five isobaric sequence permutations of glycine, histidine and lysine cannot be reached by any mass measurement at any accuracy

3 Primary sources & evidence

The index reports the design and provenance of the literature, not a conclusion about effect.

Published literature exists and is predominantly in vitro and animal, with formulation and permeation methodology forming a distinct and active strand. The topical copper-complex file is graded D, animal and in-vitro evidence only, and a separate systemic file is cross-referenced. Identifiers, by study type: reviews and mechanism syntheses — Pickart L, Margolina A, Cosmetics 2015, DOI 10.3390/cosmetics2030236; peptide-chemistry and cell-based work — Choi HR et al., J Pept Sci 2012, DOI 10.1002/psc.2455; computational and structural work — Alshammari MK et al., Comput Biol Chem 2020, DOI 10.1016/j.compbiolchem.2020.107265; formulation and delivery methodology — Dymek M et al., Pharmaceutics 2023, DOI 10.3390/pharmaceutics15102485, and Ogorek et al., Molecules 2025, DOI 10.3390/molecules30010136, the latter's title conceding that the field is still establishing how to measure permeation of the encapsulated complex. No adequately powered, independent, placebo-controlled human randomized controlled trial with biopsy-confirmed endpoints was identified. Critical attribution rule for this record: the great majority of the literature above was generated on the copper complex. A substantial literature exists on copper-free GHK as a distinct entity, and only that subset belongs here. Citing the GHK-Cu file as evidence for this article is misattribution and is refused on the certificate, the product page and the research record alike.

4 Storage & specification

Storage

White to off-white lyophilized or crystalline powder in a Type I amber glass vial with a PTFE-lined closure; this is a laboratory-chemical presentation, not a stoppered and crimped injection vial, and it carries no sterility claim. Store at -20 degrees C plus or minus 5 degrees C, desiccated, tightly closed, protected from light. The salt is hygroscopic — a histidine and lysine peptide salt takes up water quickly in open air — so Karl Fischer runs at release and at every retest point, the label carries a close-immediately-after-weighing instruction, and the sealed vial is equilibrated to ambient temperature before opening so that atmospheric moisture does not condense onto the cake. Keep physically segregated from GHK-Cu and from all copper salts, on a different shelf and with a different weighing area, because trace copper contamination converts part of this article into the neighboring one and does so visibly. Reconstituted solution is aliquoted single-use and held at -80 degrees C. Ships ambient with a labeled cumulative excursion allowance and a single-use temperature logger in every export carton.

Shelf life

Provisional 24 months at -20 degrees C plus or minus 5 degrees C, desiccated and protected from light, from the date of QA release, stated as provisional pending the company's own stability data. Stability-indicating attributes: total related substances by the stability-indicating RP-HPLC gradient, Karl Fischer water, and the copper number, which is retested at each stability pull rather than only at release because copper ingress is a storage failure mode and not only an incoming-material one. Interim pulls at 3, 6, 9 and 12 months real time at the labeled condition plus 6 months accelerated at 40 degrees C and 75 percent relative humidity. Extension beyond 24 months only on real-time data from three commercial lots. Printed retest date on every vial, first-expiry-first-out enforced against that date rather than against receipt date; material passing retest is re-dated for a further 12 months, material failing is destroyed and the destruction is recorded.