GHK-Cu is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-03-20. Numbers and descriptions here follow the published literature rather than marketing material.
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.
The International Nomenclature of Cosmetic Ingredients lists the substance as copper tripeptide-1, the name that appears on most topical product labels. Related designations include copper peptide and GHK-Cu, and the hyphenated form is common in research literature. In cosmetics the material is regulated as an ingredient rather than as a drug, so products may reach the market without evidence of the effects claimed for them. Whether those effects are clinically meaningful is an open question, since most supportive data come from laboratory work and small trials.
The copper-binding activity of this sequence was described in the 1970s during studies of liver tissue and plasma factors. Early work identified the peptide as a component that influenced copper uptake by cells and that appeared in wound fluid. Later investigations examined its presence across species, reporting the same chain in human and animal samples. A decline in measured concentration with age became a recurring observation, although the underlying causes remain incompletely characterised.
Published studies describe the complex in several research contexts, including collagen synthesis, antioxidant behaviour, and wound repair models. Much of this work is conducted in cultured cells or in small animal systems, and the findings are frequently cited in reviews of copper peptides. Direct clinical evidence in humans is comparatively limited, and reported outcomes vary with formulation and study design. Whether free chain or metal-bound form was used is not always stated, a point that complicates comparison between reports.
GHK-Cu is a coordination complex formed between the peptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The unbound chain, abbreviated GHK, consists of three amino acids and occurs naturally in human plasma, saliva, and urine. Binding of the metal is mediated mainly by the imidazole nitrogen of the histidine residue together with backbone amides, producing a stable chelate. Ingredient nomenclature often lists the same substance as copper tripeptide-1. Its charge and solubility behaviour differ from those of the metal-free chain.
| 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 |
The sequence carries three residues in the order glycine, histidine, lysine, which places a small, flexible chain around a single metal centre. Compared with larger copper-binding proteins, the complex is compact and its coordination chemistry can be reproduced with synthetic peptide in a laboratory. Published structural work agrees on the nitrogen donor set but differs in the exact geometry assigned under some conditions, so the arrangement is best treated as well characterised in outline rather than fixed in every detail.
GHK-Cu is a coordination complex formed between the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The peptide was isolated from human plasma in the early 1970s by Loren Pickart, who observed that a plasma fraction from young donors stimulated growth in cultured liver cells. The copper-bound form is abbreviated GHK-Cu, while the metal-free peptide is written simply as GHK. In the research literature the complex also appears as copper tripeptide-1 and as glycyl-histidyl-lysine copper complex.
Copper(II) binds the peptide through four nitrogen donors: the terminal amino group, the imidazole nitrogen of histidine, and two deprotonated amide nitrogens of the peptide backbone. This tetradentate arrangement gives a roughly square-planar geometry, the thermodynamically favoured form near neutral pH. Because the amide nitrogens must lose a proton before they can coordinate, complex formation is strongly pH-dependent, and the fully coordinated species dominates only above mildly acidic conditions. Electronic transitions within the copper d orbital set produce the characteristic blue to violet colour in aqueous solution.
The molecular weight and charge of GHK-Cu depend on the pH and the number of coordinated ligands. At neutral pH, the peptide typically binds one copper ion, but ternary complexes with other biomolecules can form. Spectroscopic methods such as electron paramagnetic resonance and circular dichroism are used to study the coordination environment. Reports on the exact geometry vary because the complex is dynamic in solution. Researchers often use synthetic GHK-Cu rather than extracted material to control stoichiometry and purity.
GHK-Cu is a coordination complex formed from the tripeptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The peptide binds copper through its histidine imidazole nitrogen, the terminal amino group, and the deprotonated amide nitrogen. This arrangement creates a square-planar or distorted geometry around the metal center, depending on pH and the presence of competing ligands. The complex occurs naturally in human plasma, saliva, and urine at low concentrations, and its sequence is conserved across many vertebrate species.
In evolution, the most important role of such chromosomal rearrangements may be to accelerate the divergence of a population into new species by making populations less likely to interbreed, thereby preserving genetic differences between these populations. Sequences of DNA that can move about the genome, such as transposons, make up a major fraction of the genetic material of plants and animals, and may have been important in the evolution of genomes. For example, more than a million copies of the Alu sequence are present in the human genome, and these sequences have now been recruited to perform functions such as regulating gene expression. Another effect of these mobile DNA sequences is that when they move within a genome, they can mutate or delete existing genes and thereby produce genetic diversity. Nonlethal mutations accumulate within the gene pool and increase the amount of genetic variation. The abundance of some genetic changes within the gene pool can be reduced by natural selection, while other "more favorable" mutations may accumulate and result in adaptive changes.
Other psychedelics not belonging to any of the above three structural families have been discovered, for instance certain arylpiperazine derivatives like quipazine, the antiretroviral drug efavirenz, and simplified or partial lysergamides (which are also conformationally constrained tryptamines and/or phenethylamines) like NDTDI (9-nor-LSD; 8,10-seco-LSD) and UCD0120 (dides-B,C-LSD).
=== Technical issues during the flight === On the 19th orbit, the first sign of trouble appeared when the spacecraft 0.05 g (0.5 m/s2) light came on. However, this turned out to be a faulty indicator, and the spacecraft was not reentering. On the 20th orbit, Cooper lost all attitude readings. The 21st orbit saw a short-circuit occur in the bus bar serving the 250 VA (115 V, 400 Hz) main inverter. This left the automatic stabilization and control system without electric power. On the 21st orbit, John Glenn on board the tracking ship Coastal Sentry Quebec near Kyushu, Japan, helped Cooper prepare a revised checklist for retrofire. Due to the system malfunctions, many of the steps would have to be done manually. Only Hawaii and Zanzibar were in radio range on this last orbit, but communications were good. Cooper noted that the carbon dioxide level was rising in the cabin and in his spacesuit. He told Carpenter as he passed over Zanzibar, "Things are beginning to stack up a little." Throughout the problems, Cooper remained cool, calm and collected. Cooper did not experience much of an appetite during the flight and ate only because it was scheduled. The food containers and water dispenser system proved unwieldy and he was not able to properly prepare freeze-dried food packages, so he limited his consumption to cubed food and bite-sized sandwiches. Cooper found the cubed food largely unpalatable, which contributed to his lack of eating.
According to the manufacturer's website, the insulin's action profile in cats was similar to that of NPH insulin, and it lowered blood sugar quickly, but for only about 6–8 hours. Vetsulin was recalled in the US in November 2009 due to inconsistent strength; it was available again as of April 2013. Two ultra-slow time-release synthetic human insulins became available in 2004 and 2005, generically known as insulin detemir (Levemir) and insulin glargine (Lantus). Studies have had good results with insulin glargine in cats. Follow-up research shows that Levemir can be used with a similar protocol and that either insulin on this protocol can lead uncomplicated feline cases to remission, with the most success being in cats who start on these protocols as soon as possible after diagnosis.
Sources: en.wikipedia.org
== History == The word comes from the Greek ἀφροδισιακόν, aphrodisiakon 'sexual, aphrodisiac', from aphrodisios 'pertaining to Aphrodite', the Greek goddess of love. Throughout human history, food, drinks, and behaviors have had a reputation for making sex more attainable and/or pleasurable. However, from a historical and scientific standpoint, the alleged results may have been mainly due to mere belief on the part of their users that they would be effective (a placebo effect). Likewise, many medicines are reported to affect libido in inconsistent or idiopathic ways: enhancing or diminishing overall sexual desire, depending on the circumstances. For example, bupropion (Wellbutrin) is known as an antidepressant that can counteract other co-prescribed antidepressants with libido-diminishing effects. However, because bupropion increases libido only when it is already impaired by related medications, it is not generally classed as an aphrodisiac. Ancient civilizations like Chinese, Indian, Egyptian, Roman, and Greek cultures believed that certain substances could provide the key to improving sexual desire, sexual pleasure, and/or sexual behavior. This was important because some men suffered from erectile dysfunction and could not reproduce. Men who could not impregnate their wives and father large families were seen as failures, whereas those who could were respected. Hence, a stimulant was needed. Others who did not suffer from this also desired performance enhancers.
Complications of diabetes are secondary diseases that are a result of elevated blood glucose levels that occur in diabetic patients. These complications can be divided into two types: acute and chronic. Acute complications are complications that develop rapidly and can be exemplified as diabetic ketoacidosis (DKA), hyperglycemic hyperosmolar state (HHS), lactic acidosis (LA), and hypoglycemia. Chronic complications develop over time and are generally classified in two categories: microvascular and macrovascular. Microvascular complications include neuropathy, nephropathy, and retinopathy; while cardiovascular disease, stroke, and peripheral vascular disease are included in the macrovascular complications. The complications of diabetes can dramatically impair quality of life and cause long-lasting disability. Overall, complications are far less common and less severe in people with well-controlled blood sugar levels. Some non-modifiable risk factors such as age at diabetes onset, type of diabetes, gender, and genetics may influence risk. Other health problems compound the chronic complications of diabetes such as smoking, obesity, high blood pressure, elevated cholesterol levels, and lack of regular exercise. Complications of diabetes are a strong risk factor for severe COVID-19 illness.
=== Treatment === The US CDC reports no specific antidote for azide poisoning. A 2021 narrative review identifies several cases of survival from ingestion when the patient is treated with antidotes for cyanide poisoning. From a mechanistic standpoint, hydroxocobalamin is more likely to be helpful than other antidotes such as sodium nitrite and sodium thiosulfate. As a result, the recommended treatment is hemodynamic support and hydroxocobalamin. First responders should use personal protection equipment to protect themselves from azide exposure.
The lethal dose of psilocybin when administered intravenously in mice is 285 mg/kg, in rats is 280 mg/kg, and in rabbits is 12.5 mg/kg. Psilocybin comprises approximately 1% of the weight of Psilocybe cubensis mushrooms, and so nearly 1.7 kilograms (3.7 lb) of dried mushrooms, or 17 kilograms (37 lb) of fresh mushrooms, would be required for a 60-kilogram (130 lb) person to reach the 280 mg/kg LD50 value of rats. Based on the results of animal studies and limited human case reports, the human lethal dose of psilocybin has been extrapolated to be 2,000 to 6,000 mg, which is around 1,000 times greater than its effective dose of 6 mg and 200 times the typical recreational dose of 10 to 30 mg. The Registry of Toxic Effects of Chemical Substances assigns psilocybin a relatively high therapeutic index of 641 (higher values correspond to a better safety profile); for comparison, the therapeutic indices of aspirin and nicotine are 199 and 21, respectively. The lethal dose from psilocybin toxicity alone is unknown, and has rarely been documented—as of 2011, only two cases attributed to overdosing on hallucinogenic mushrooms (without concurrent use of other drugs) have been reported in the scientific literature, and those may involve factors other than psilocybin.
=== Cosmetics === Some sucrose esters, such as sucrose distearate, sucrose dilaurate, sucrose palmitate, etc. are added in cosmetics products as an emulsifier. Some have a function in skin conditioning and emollient. Cosmetics products that might have sucrose esters as an ingredient includes eyelash products, hair treatments, oil gels, skin products and deodorants.
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.
GHK denotes the unbound chain of three amino acids. GHK-Cu describes the form in which a copper(II) ion is held by that chain. The two are not interchangeable in solution, since charge, molecular weight, and reactivity differ.