Everything below concerns copper tripeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-12-16. Where a claim depends on a specific study, the study is described rather than over-claimed.
GHK-Cu is the copper complex of the tripeptide glycyl-L-histidyl-L-lysine, a short sequence found naturally in human plasma, saliva and urine. Loren Pickart reported the isolation of the free peptide in 1973 while studying factors that influenced the growth of aged liver cells in culture. The peptide was later shown to bind copper(II) with high affinity, and the metal-bound form became the focus of most subsequent research. Its concentration in circulation declines markedly with age, a pattern that is well documented, though the physiological consequences of that decline remain debated.
The peptide portion consists of three amino acids: glycine, histidine and lysine. Copper(II) coordinates through the imidazole nitrogen of histidine, the alpha-amino group of glycine and a deprotonated amide nitrogen of the backbone, producing a roughly square-planar geometry. This arrangement gives the complex its characteristic blue-to-violet colour and helps it resist dissociation in water. Reported stability constants are high, although values differ between studies because of differences in ionic strength and measurement method.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The peptide backbone consists of glycine, histidine, and lysine joined in that order. Copper is held through the imidazole nitrogen of histidine and the alpha-amino group at the N-terminus, which together produce a square-planar arrangement around the metal center. The solid appears blue to violet, a color that originates from d-d electronic transitions within the copper coordination sphere. The complex is indexed under CAS number 89030-95-5.
The sequence now called GHK was first reported in the early 1970s after isolation from human plasma, where it was noted to influence liver cell behavior in laboratory preparations. Later work described a copper-binding form and its activity in fibroblast and wound-model experiments. Review articles frequently group the substance with other copper peptides. Concentrations in blood appear to fall with age in several small surveys, although the reason for this trend is not settled. Whether such a decline carries functional consequences remains an open question.
| Property | Value | Notes |
|---|---|---|
| INCI name | Copper tripeptide-1 | Standard designation on cosmetic ingredient labels |
| Peptide sequence | Gly-His-Lys | Three-residue ligand; binding occurs at the histidine side chain |
| Metal-to-peptide ratio | 1 to 1 | One copper(II) ion per peptide unit |
| Appearance | Blue to violet powder | Colour arises from copper-to-peptide electronic transitions |
| Water solubility | Freely soluble | Commonly formulated in aqueous or water-alcohol systems |
Copper peptide solutions tend to resist degradation better than many free peptides, because the bound metal protects the N-terminus and reduces susceptibility to some peptidases. Backbone hydrolysis, oxidation of the histidine imidazole ring, and photochemical reactions remain the principal degradation routes. Aqueous solutions are generally most stable near neutral to mildly acidic pH, while strongly alkaline conditions accelerate hydrolysis. Light exposure is usually avoided, since both the peptide and the copper center can take part in photochemical processes. Stability data published by suppliers often describe short-term behavior rather than multi-year shelf life.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, frequently paired with mass spectrometry to confirm the molecular ion. Copper content is measured separately, typically by inductively coupled plasma mass spectrometry or atomic absorption spectroscopy, because the chromatographic signal reports the peptide rather than the metal. Ultraviolet-visible spectroscopy provides a fast check on complex formation, since copper(II) peptide complexes absorb in the visible region. Elemental analysis and amino acid analysis are used less often but remain useful for reference standards. A gap between reported peptide purity and measured copper content is a recurring source of confusion.
Aqueous GHK-Cu solutions are less stable than the dry powder. Light, dissolved oxygen and elevated temperature all accelerate loss of the intact complex, and the main observable changes are fading of the blue colour and the appearance of peptide fragments. Acidic conditions protonate the histidine imidazole and weaken copper binding, while strongly alkaline conditions promote hydrolysis of the peptide backbone. Because several degradation routes operate at once, a single shelf-life figure does not describe all storage conditions.
Solid material is typically kept as a lyophilised powder in a sealed, light-protected container at minus 20 degrees Celsius, with desiccant where humidity is high. Working solutions are often prepared fresh, aliquoted and frozen to avoid repeated freeze-thaw cycles. Glassware and buffers are checked for trace metal contamination, since other transition metals can displace copper. Records of lot number, reconstitution date and storage temperature help trace unexpected colour changes. Blue colour itself is not a reliable purity test, because partly degraded solutions can remain visibly coloured.
=== Cutaneous angiofibroma === These papule, nodule, and/or tumor lesions occur on the: 1) face and are typically termed fibrous papules; 2) penis and are typically termed pearly penile papules; and 3) underneath a fingernail or toenail and are typically termed periungual angiofibromas. Some of these cutaneous AGF lesions occur in individuals with one or more of 3 different genetic diseases: tuberous sclerosis, multiple endocrine neoplasia type 1, and Birt-Hogg-Dube syndrome. The following are examples of these cutaneous angiofibromas and their alternate names.
==== Broad-spectrum antibiotics ==== This group of antibiotics is called "broad-spectrum" because they are active against a wide range of Gram-negative bacteria such as Escherichia coli and Salmonella typhi, for which penicillin is not suitable. However, resistance in these organisms is now common.
==== Ban ==== Banban Akaza (赤座 伴番, Akaza Banban), also known as "Ban" (バン), is a hot-headed, chaotic, loudmouthed, bad-tempered, yet fiercely loyal and friendly rookie member of the S.P.D., who previously trained in space before being assigned to lead S.P.D.'s Earth unit in the field as Deka Red (デカレッド, Deka Reddo). While he joins the newly created Fire Squad as an elite officer in the series finale, he occasionally returns to help his original team. Initially having an immature personality, he slowly matures throughout the series. In battle, Ban is a practitioner of the space martial art Juu Kune Do (ジュウクンドー, Jū Kun Dō), which blends unarmed martial arts skills with gunplay. As Deka Red, he dual wields a pair of D-Magnum (ディーマグナム, Dī Magunamu) rayguns, which can combine to form the Hybrid Magnum (ハイブリッドマグナム, Haiburiddo Magunamu) shotgun and allow him to perform the Magnum Execution (マグナムエクスキュージョン, Magunamu Ekusukyūjon), Moonsault Shot (ムーンサルトショット, Mūnsaruto Shotto), Endless Shot (エンドレスショット, Endoresu Shotto), Hurricane Shot (ハリケーンショット, Harikēn Shotto), and Moonsault Galaxy Shot (ムーンサルトギャラクシーショット, Mūnsaruto Gyarakushī Shotto) attacks. He also shares riding the Machine Doberman (マシンドーベルマン, Mashin Dōberuman) police car with Jasmine. If necessary, he can borrow Doggie Kruger's D-Sword Vega to perform the Akaza Sword Art: Raijin Sword (赤座剣法・雷神剣, Akaza Kenpō Raijin Ken) and Impulse Vega Slash (インパルスベガスラッシュ, Inparusu Bega Surasshu) attacks. During the events of the crossover film Mahō Sentai Magiranger vs.
Sources: en.wikipedia.org
=== Nanoscale and spectroscopy below the diffraction limit === The spatial resolution of FTIR can be further improved below the micrometer scale by integrating it into scanning near-field optical microscopy platform. The corresponding technique is called nano-FTIR and allows for performing broadband spectroscopy on materials in ultra-small quantities (single viruses and protein complexes) and with 10 to 20 nm spatial resolution.
== Applications == Alpha emitters such as actinium-225 are favored in cancer treatment because of the short range (a few cell diameters) of alpha particles in tissue and their high energy, rendering them highly effective in targeting and killing cancer cells—specifically, alpha particles are more effective at breaking DNA strands. The 10-day half-life of 225Ac is long enough to facilitate distribution, but short enough that little remains in the body months after treatment. Additionally, each decay of 225Ac to 209Bi nets four high-energy alpha particles, greatly increasing its potency. Despite its limited availability, several clinical trials have been completed, demonstrating the effectiveness of 225Ac in targeted alpha therapy. Complexes including 225Ac—such as antibodies labeled with 225Ac—have been tested to target various types of cancer, including leukemia, prostate carcinoma, and breast carcinoma in humans. For example, one experimental 225Ac-based drug has shown effectiveness against acute myeloid leukemia without harming the patient. Further clinical trials of other drugs are underway such as the SatisfACtion trial (NCT04597411), a Phase I/II, open-label, multi-center study that is evaluating 225Ac-PSMA-R2 in patients with metastatic hormone-sensitive prostate cancer (mHSPC) and metastatic castration-resistant prostate cancer (mCRPC).
The KiSS1-derived peptide receptor (also known as GPR54 or the Kisspeptin receptor) is a G protein-coupled receptor which binds the peptide hormone kisspeptin (metastin). Kisspeptin is encoded by the metastasis suppressor gene KISS1, which is expressed in a variety of endocrine and gonadal tissues. Activation of the kisspeptin receptor is linked to the phospholipase C and inositol trisphosphate second messenger cascades inside the cell. Kisspeptins are neuropeptides synthesized in the hypothalamus and encoded by the KISS1 gene. The KISS1 gene encodes the G protein-coupled receptor 54 (known as KISS1R or GPR54) and plays a crucial role in regulating reproduction, pubertal maturation, and metabolic function. KISS1 neurons located in the arcuate nucleus (ARC) of the mediobasal hypothalamus (MBH) project to GnRH neurons in the median eminence, which expresses KISS1R, to stimulate LH secretions in a pulsatile manner from the anterior pituitary to initiate ovulation/ pubertal maturation. The KISS1 and KISS1R/GPR54 genes have been detected in the brain, pituitary, placenta, pancreas, liver, and small intestine.
Sources: en.wikipedia.org
It is a complex of a three-amino-acid peptide, glycine, histidine and lysine, bound to a single copper(II) ion. The metal is held mainly by the histidine side chain and the peptide backbone. Most commercial material is supplied as an acetate salt rather than as the free complex.
The free peptide was reported in 1973 by Loren Pickart, who isolated it from human plasma. Its copper-binding behaviour was characterised over the following years. The metal-bound form has been the subject of most later research.
Yes. Copper tripeptide-1 is the name used in cosmetic ingredient labelling, while GHK-Cu is the shorthand found in the scientific literature. Both refer to the same peptide-copper complex, and the two terms are interchangeable in most technical documents.
It is the copper complex of the tripeptide glycyl-L-histidyl-lysine. The metal ion is held by the histidine imidazole group and the peptide N-terminus. Most research on it concerns skin and wound models.