Peptides are chains of amino acids that sit between individual amino acids and proteins. This article examines copper peptide, carnosine, glutathione, frog antimicrobial peptides, and plant-derived antioxidant peptides, covering their mechanisms, applications in cosmetics, and representative…
A detailed overview of the most common peptides in cosmetics, published on
, begins by placing peptides in the middle of the protein world. Peptides are functional nutrients that fall between individual amino acids and larger protein molecules. They are noted for being highly active and easily absorbed, and they can stimulate the body's own regeneration system. In chemical terms, peptides are generally formed when three or more amino acid molecules undergo dehydration condensation, a reaction in which a water molecule is removed and the amino acids are joined by amide bonds, typically written as -CONH-.
Copper peptide, sometimes called blue copper peptide, is a complex formed between copper ions and amino acids. It is primarily found in marine organisms. The combination of copper ions and a specific amino acid sequence gives it distinctive properties and functions that make it useful in skin repair products.
The discovery path goes back to Dr. Loren Pickart, who isolated a tripeptide from human plasma. That tripeptide spontaneously forms a complex when it meets divalent copper ions, meaning copper ions with a charge of +2. The resulting complex has been shown to help treat wounds and repair damaged skin, which is why copper peptide is considered one of the longest-used and most representative reparative ingredients in skin care. Copper peptide also supports the production of collagen and glycosaminoglycans, accelerates cell proliferation, and thereby promotes wound healing.
In cosmetics, copper peptide usually appears in a form called blue copper peptide, with the scientific name Tripeptide-1 Copper. Because of its skin repair, anti-inflammatory, and moisturizing effects, it is widely used in the medical and aesthetic industries. It can reduce the appearance of scars in wound repair surgeries, promote healing after skin acne lesions, and repair skin that has been damaged. Copper peptide also has antioxidant and anti-inflammatory properties, and it functions as an antioxidant and activator during tissue remodeling.
Several brands have added copper peptide to their product lines. JM Solution and Cosmetic Skin Solution, a U.S.-based skincare brand, both include copper peptide products such as copper peptide serums. At present, copper peptide is used mainly as an antioxidant or moisturizer in skincare, and it is used in medical aesthetics for scar repair. Its use has not become fully widespread, largely because of its cost.
| Catalog # | Product Name | M.W. | Molecular Formula |
| --- | --- | --- | --- |
| CPC1613 | Copper Peptide GHK-Cu | 403.94 | C14H22CuN6O4 Cu complex |
| CPC1658 | Copper Peptide GHK 2·Cu | 744.32 | C28H46CuN12O8 |
| CPC1708 | Prezatide Copper | 740.282 | C28H44CuN12O8 |
| R1966 | Prezatide Copper Acetate | 862.39 | C32H54CuN12O12 |
| HB00125 | Acetyl hexapeptide-3 | 888.99 | C34H60N14O12S |
Carnosine has the scientific name β-alanylhistidine. It is a dipeptide built from two amino acids: β-alanine and L-histidine. In its pure form, carnosine is a crystalline solid. It has strong antioxidant properties and can directly neutralize free radicals. The histidine residue in its side chain acts as a hydrogen donor, capturing free radicals before they can damage cells. This antioxidant ability makes carnosine especially relevant for anti-aging. Recent studies have also suggested that carnosine's antioxidant mechanism may be linked to the inhibition of telomere shortening.
Carnosine also plays a role in the body's response to excess sugar. When sugar intake is too high, surplus glucose can react with proteins, amino acids, or lipids in a process called non-enzymatic glycation. That reaction can lead to the breakdown of collagen and a loss of skin elasticity. Carnosine can act as a substitute in these reactions, preventing glycation from crosslinking proteins. In doing so, it helps restore skin elasticity and brightens skin tone. In addition, carnosine helps maintain the activity of superoxide dismutase SOD , an enzyme that defends against oxidative stress, and it can neutralize large amounts of lactic acid produced by muscles. It also serves to buffer physiological pH.
Carnosine is considered one of the earliest bioactive peptides used in the beauty and skincare industry. It has nearly a century of chemical synthesis history, and its manufacturing process is well established. Along with copper peptides and palmitoyl tripeptides, carnosine is one of the most widely used peptides in cosmetics, and it appears in many international skincare lines. L'Oréal's La Roche-Posay uses carnosine in several product families, including the La Roche-Posay Effaclar Duo+ Acne Treatment. Olay has also incorporated carnosine into products such as the Olay Regenerist Micro-Sculpting Serum. Other brands that include carnosine in their formulations are Chando and Elizabeth Arden.
The table below shows carnosine-related products in the Creative Peptides catalog:
| Catalog # | Product Name | M.W. | Molecular Formula |
| --- | --- | --- | --- |
| CPC1634 | Carnosine | 226.23 | C9H14N4O3 |
| 10-101-223 | N-Acetyl Carnosine | 268.27 | C11H16N4O4 |
| CPC1681 | Decarboxy Carnosine HCl | 255.14 | C8H16Cl2N4O |
| R1914 | L-Homocarnosine | 240.26 | C10H16N4O3 |
Glutathione is a tripeptide that contains a γ-amide bond and a thiol group. It is built from glutamic acid, cysteine, and glycine, and it is found in nearly every cell in the body. The thiol group -SH on its cysteine residue is the active group. Under normal physiological conditions, glutathione exists mainly in its reduced form, abbreviated G-SH, but it can also be found in an oxidized form called G-S-S-G. The enzyme glutathione reductase helps these two forms interconvert.
Recent studies show that glutathione can reduce pigmentation by inhibiting melanin production. This makes it useful for preventing the formation of lipofuscin, or age spots. When combined with Vitamin C, glutathione has been shown to treat melasma in women effectively. Some experiments have also found that glutathione has tyrosinase inhibitory properties, which supports its use as a whitening ingredient.
The thiol group on cysteine also has strong nucleophilicity, meaning it tends to donate electrons to electron-poor targets. This allows glutathione to bind heavy metal ions, drug metabolites, and other intermediates, forming complexes that are non-toxic or only mildly toxic. These complexes are then excreted from the body, which gives glutathione a role in detoxification. For melasma treatment, clinicians sometimes combine glutathione with other agents, such as the Jing Tian Sedum capsule for melasma removal, or with Vitamin C for dark spot treatment.
Several well-known brands use glutathione in their products. Japanese brand Shiseido's Anessa sunscreen is known for containing a significant amount of glutathione. The French brand Filorga includes glutathione in its Brightening Collection, such as the Filorga Comfort Brightening Serum. Other brands that feature glutathione include The Ordinary, Laneige, and Gu Yu.
After oil is extracted from the frog's skin, it is rich in collagen and displays some biocompatibility and biodegradability of functional proteins. It is considered a non-toxic active substance. After self-assembly or cross-linking, the extracted material can form collagen fibers with a certain amount of strength and an ability to adhere to wounds, which gives it a repair effect. The oil also contains a variety of amino acids and trace elements, including a high concentration of human chorionic gonadotropin, making it an ideal source of nutritional proteins. Theoretically, it also has antioxidant properties, and for these reasons it is seen as useful in biotechnology and medical fields.
The ability of soy peptides to scavenge hydroxyl radicals is closely connected to the exposure of their amino acid side chains. Their antioxidant mechanisms are diverse and include directly capturing reactive oxygen species ROS , activating the body's antioxidant enzyme system, and chelating metal ions. Together, these actions provide a comprehensive antioxidant effect, which makes soy protein-derived antioxidant peptides broadly applicable in nutritional supplements, functional foods, and cosmetics.
The table below summarizes the functional characteristics of copper peptide, carnosine, glutathione, and frog antimicrobial peptide as described in the article.
| Peptide Type | Functional Characteristics |
| --- | --- |
| Copper Peptide | Promotes production of collagen and glycosaminoglycans, helps wound healing and skin tightening, has antioxidant properties, reduces free radical damage, has anti-inflammatory effects, helps repair skin inflammation, improves signs of skin aging, enhances skin elasticity |
| Carnosine | Strong antioxidant capacity, clears free radicals, protects cells from oxidative damage, helps reduce melanin production and improve skin tone, reduces wrinkles and increases hydration, maintains immune system stability and cell viability, enhances physical strength and endurance in athletics |
| Glutathione | Acts as an internal antioxidant weapon, provides broad antioxidant effects, protects cells, has detoxifying, whitening, and anti-aging effects, helps remove toxic substances, repairs liver damage, improves immunity, whitens skin and improves uneven tone in skincare |
| Frog Antimicrobial Peptide | Immune-boosting, inhibits activity of viruses, bacteria, and tumors, strengthens immune system, enhances resistance, has antiviral, anticancer, and liver-protecting effects in clinical use, including hepatitis treatment, and thymosin peptide is widely used as an immune factor in antiviral and health-support therapies |
Not every peptide in this list has the same level of commercial development. Copper peptide is well established in wound repair and cosmetic products, carnosine has nearly a century of manufacturing history, glutathione is widely used for pigmentation and detoxification, and frog antimicrobial peptides remain comparatively early in their development. Together, these peptides show how the same class of molecules can work in different ways to protect, repair, and brighten the skin.
Peptides referenced: GHK-Cu, Argireline, Copper Tripeptide-1, Glutathione, HCG.
Related reading: Condensation Agents in Solid-Phase Peptide Synthesis, Macrocyclic Peptide Drugs: Structures, Pipelines and Oral Prospects, Representative Peptides for In Vivo Tumor Imaging, Six biocatalytic strategies for enzymatic oligopeptide synthesis.