GHK-Cu is a complex consisting of the tripeptide GHK (glycyl-histidyl-lysine) and copper (Cu). GHK was first discovered in 1973 by Dr. Loren Pickart, who found it caused older human liver tissue to produce proteins more characteristic of younger tissue. This resulted in GHK being originally described, specifically, as a liver cell growth factor. However, as research continued, experts found that GHK could modulate a number of different cells besides those in the liver.
GHK is naturally found in human saliva, plasma, and urine, but its standard levels are reduced by over half once you reach age 60. As researchers note, this decline âcoincides with the noticeable decrease in regenerative capacity of an organism. This suggests that, for example, lower natural GHK levels may contribute to things like slower wound healing in older adults.
According to experts, GHK has a âstrong affinity for copperâ and âreadilyâ links up with it to form GHK-Cu. In this form, the peptide complex appears to have strong protective and regenerative properties, leading to its widespread use in cosmetics.
What is GHK-Cu used for?
Most often, youâll find GHK-Cu copper peptides (usually listed in ingredient lists under the name Copper Tripeptide-1) in various cosmetics, with skin care products being some of the most popular use cases. According to a 2018 review, GHK-Cu has demonstrated the ability to:
Tighten loose skin
Reverse age-related skin thinning
Repair the skinâs protective barrier proteins
Improve skin firmness and elasticity
Reduce the appearance of fine lines and wrinkles
Smooth rough skin
Stimulate wound healing
Lessen the appearance of photodamage (sun damage), hyperpigmentation, skin spots, lesions, and more
Reduce inflammation and damage from free radicals
Increase hair growth and thickness
Additionally, in research from 2015, the authors noted that GHK-Cu may be able to stimulate collagen, regulate the skin remodeling process, attract immune cells to the site of an injury, and restore âreplicative vitality to fibroblastsâ (a cell that helps form connective tissue) in patients whoâve undergone radiation therapy for cancer.
To help you better understand how GHK-Cu works, weâll break down some of the research behind the peptideâs potential applications for hair, skin, and other health aspects.
Skin aging
In a 2018 review, the authors detailed multiple positive studies and trials on the use of GHK-Cu for signs of skin aging. One trial had 71 women with âmild to advanced signs of photoagingâ apply a facial cream containing GHK-Cu daily for three months and found that the treatment increased skin density and thickness while reducing sagging and the appearance of fine lines and wrinkles. In another trial, 41 women with âmild to advanced photodamageâ applied GHK-Cu eye cream for three months; it reduced lines and wrinkles, improved skin density, and increased skin thickness better than both placebo and vitamin K cream.
Similarly, in a pilot study investigating copper tripeptide topicals for aged skin, experts found that they increased skin thickness, improved hydration, boosted collagen synthesis, and increased elasticity.
Hair growth
In a review from 2023, experts explained that GHK-Cu may promote hair growth in a few different ways. The first is by stimulating fibroblasts and promoting the formation of new blood vessels to help hair follicles receive the nutrients needed to grow. Second, GHK-Cu appears to inhibit growth factor beta, thereby preventing hair follicles from prematurely shrinking. And lastly, GHK-Cu may support dermal papilla cells (an important cell for healthy hair formation) to stimulate hair growth.
Wound healing
In animal studies, GHK-Cu has demonstrated wound-healing abilities. In one rabbit study, it improved âwound contraction and formation of granular tissue,â boosted antioxidant enzymes, and stimulated blood vessel development and growth. Also, a collagen dressing with GHK-Cu accelerated the healing of wounds in both healthy and diabetic rats.
However, researchers point out that GHK-Cu is âvery sensitiveâ to breakdown by certain enzymes. Wounds like diabetic skin ulcers and bedsores often develop something called a âwound serumâ that contains these enzymes. This âserumâ breaks down GHK-Cu, rendering it ineffective.
Tissue regeneration
An in vitro study found that treating lung fibroblasts from COPD patients with GHK-Cu helped restore their function. The researchers also suggested that GHK-Cu may be able to reverse gene expression changes associated with emphysema.
Anti-cancer actions
Because GHK-Cu can activate cell growth, tissue remodeling, and blood vessel development, experts express concerns about its potential to trigger cancer. Interestingly, though, GHK-Cu appears to possess âpotentâ anti-cancer properties. The peptide is one of two skin remodeling substances that may be able to downregulate the expression of âmetastaticâ genes.
In an older 1983 animal study (published in 2014) that was conducted in part by Dr. Pickart, who discovered the peptide, a mixture of GHK-Cu and vitamin C suppressed the growth of a highly malignant cancer in mice called sarcoma-180.
Anti-pain effects
GHK-Cu also appears to possess analgesic, or anti-pain, effects. In one mouse study, researchers found that the peptide reduced the pain felt by the animals in their paws when âplaced on a mildly hot plate.â The authors explained that this could be because GHK is similar in structure to cimetidine, a histamine H2 receptor antagonist sometimes given to reduce pain in certain digestive conditions.
With all of this in mind, itâs not surprising that GHK-Cu has become a popular ingredient in topicals intended to reduce a host of skin- and hair-related concerns. And as detailed above, you may soon see this peptide being used as a part of therapy or treatment for other health conditions. As the science develops, weâll update this guide accordingly.
Are GHK-Cu copper peptides safe?
To date, no existing research has discovered any serious safety concerns with the use of GHK-Cu copper peptides.
In fact, one study noted that the peptide âhas a long history of safe use in wound healing and skin care; it is naturally occurring, nontoxic, and is active at a very low nanomolar concentration.â In addition, another piece of research described GHK-Cu as âa safe, inexpensive, extensively studied compound.â
However, though this is reassuring, there are a couple of things to remain mindful of:
Copper toxicity
Since GHK-Cu contains copper, itâs important to only use products containing it as directed to avoid potential copper toxicity.While itâs unlikely that using GHK-Cu products will cause copper toxicity, especially since the concentrations of the peptide are typically well within safe parameters, itâs still good to be aware of the possible risk.
Some symptoms of copper poisoning may include abdominal pain, vomiting, chest pain, chills, cough, fever, general weakness, anemia, burning sensations, tremors, and a metallic taste in the mouth.
Angiogenesis and cancer
GHK-Cu may promote the formation of new blood vessels, or angiogenesis. As explained by the U.S. National Cancer Institute, âAngiogenesis plays a critical role in the growth of cancer because solid tumors need a blood supply if they are to grow beyond a few millimeters in size.â
So, despite GHK-Cuâs potential anti-cancer action, those who have active or suspected cancer may still wish to avoid using products containing the peptide. And if you develop any symptoms of cancer while using GHK-Cu, itâs best to discontinue use and contact your doctor for their input and potential testing.
Itâs also important to point out that there havenât been any studies investigating the long-term use of this peptide in humans, so we currently donât know if there are any potential downsides or dangers to using it for an extended period.
Common side effects of GHK-Cu
Before adding GHK-Cu to your routine, itâs important to first conduct patch testing â as you should with any new topical product. Even if GHK-Cu doesnât cause a reaction, you may still have a sensitivity or allergy to one of the other ingredients in the product youâre using.
If GHK-Cu does happen to cause any adverse reactions, theyâre typically mild and transient (meaning they should go away over time). Common side effects include redness, itching, or irritation at the application site. If you experience any severe reactions like hives, swelling, difficulty breathing, etc., then itâs important to stop using the product right away, gently wash it off with cool water, and either contact your doctor or seek prompt medical attention if necessary.
GHK-Cu and âcopper ugliesâ
Albeit rare, some people may experience a side effect from using GHK-Cu or other copper peptides known as âcopper uglies.â Though there arenât any studies on this phenomenon, some users have anecdotal reports of copper peptide skin care products leading to what looks like accelerated skin aging instead of antiaging.
This may be due to copperâs ability to enhance the expression of metalloproteinases (MMPs). Now, the degradation of collagen is normally regulated by MMPs, and a specific one, MMP-1, may be responsible for âthe initiation of collagen fragmentation.â Supporting this, a 2024 study noted that elevated MMP-1 levels appear to contribute to aging skin. The study authors found that higher MMP-1 levels in mice led to:
The loss and fragmentation of dermal collagen fibrils
Contracted fibroblast morphology
Reduced collagen production
Increased expression of pro-inflammatory mediators
Keeping that in mind, a 2016 study found that GHK-Cu âsignificantly increased gene expression of MMP-1 and MMP-2 at the lowest concentration.â The studyâs authors considered this to be one of the reasons the peptide was able to increase collagen and elastin production.
So, what this could ultimately mean is that using too much GHK-Cu (or other copper peptides) may â in theory â increase the skinâs MMP-1 concentration above the levels involved in healthy collagen production and take it into the âcollagen fragmentation and breakdownâ territory seen in older skin with naturally higher MMP-1 levels.
Again, the âcopper ugliesâ are rare, but itâs still best to conduct a spot test elsewhere on your body before applying GHK-Cu peptides to the face. It could also be worth checking the ingredients of the skin care products in your daily regimen to ensure you arenât using multiple copper peptide products all at once.
Who are GHK-Cu peptides for?
Based on both the information we learned from knowledgeable medical professionals and what researchers have suggested GHK-Cu has the potential to do, those whoâd likely benefit the most from using products containing the peptide include:
People seeking an antiaging product for wrinkles, fine lines, and/or sagging skin
Those who would prefer an alternative to other, often harsh antiaging actives like tretinoin or glycolic acid
Individuals with inflammatory skin conditions (e.g., eczema, rosacea, etc.)
People looking to reduce the appearance of striae, or stretch marks
Those with scarring due to injuries, surgeries, or acne
Individuals dealing with hyperpigmentation concerns (e.g., melasma, dark spots)
Anyone seeking a proactive skin health product
People who would like to or who need to find an alternative hair growth solution
Individuals with slow-healing wounds that arenât bedsores or due to diabetes
Those with acne, including cystic acne
When it comes to some of the other potential applications we detailed earlier in this guide â like pain relief and anti-cancer activity â more human research is needed before we can definitively say it should be used by individuals for those purposes. If youâre being treated for pain or cancer, itâs best to stick with what your doctor prescribes. This is especially important for cancer patients, as GHK-Cu may even increase the risk of cancer progression (more on that below).
Who should avoid GHK-Cu?
Because of its history of safe use, there arenât too many populations that should avoid using GHK-Cu. However, that doesnât mean there arenât any. Those who should reconsider or avoid copper peptides like GHK-Cu include:
Anyone under the age of 18: We donât yet know if copper peptides can have an adverse effect on young people.
Those who are pregnant or breastfeeding: Similar to the above point, there isnât enough research on whether or not copper peptides can affect a developing fetus or be transferred into breast milk.
People with active or suspected cancer: Even though it may have anti-cancer potential, GHK-Cu could promote the formation of new blood vessels, which can âfeedâ tumors.
Individuals with Wilsonâs disease: This rare genetic condition causes copper to build up in your body, so using copper peptides may be dangerous.
How to use GHK-Cu peptides
Unlike many other peptide therapies, GHK-Cu typically isnât administered as an injectable; itâs most often applied topically as a cream or serum. While some clinics may offer it as an injection or even orally, most of the research on GHK-Cu has utilized topical delivery. This is why weâll primarily be focusing on what itâs like to use GHK-Cu peptides in the form of topicals. As the research on other administration methods develops, weâll update this information accordingly.
In contrast to certain ingredients, like tretinoin or retinol, GHK-Cu wonât make your skin extra-sensitive to UV rays. In fact, GHK seems to actually block âlethal ultraviolet radiation damageâ and protect the skin, per a 2014 study. This means that GHK-Cu doesnât need to be applied at a certain time; you should be able to use it either during the day or at night. But if the product instructions say to apply it during a specific time â or at different times throughout the day â itâs best to follow the manufacturerâs directions.
GHK-Cu skin care results timeline
As with most skin care products, noticeable results from topical GHK-Cu copper peptides will take some time and consistent use. Based on what our team learned from communicating with medical professionals, the general timeline is as follows:
First two weeks: Users may notice better skin hydration, reduced redness or irritation, and smoother skin.
After 1-2 months: Fine lines and wrinkles might start to noticeably fade as skin texture and elasticity begin to improve. Those with inflammatory skin conditions may also experience improvements in symptom management.
After 3-6 months: As skin elasticity and firmness continue to improve, scars and hyperpigmentation might begin to noticeably fade at this stage.
Long-term use: Continuous use could lead to sustained collagen production, maintained skin hydration, less visible wrinkles, and better overall skin health.
Of course, everyone is different, and how your skin reacts to GHK-Cu products is no exception. For example, you might not experience the first potential benefits until after a month of using the peptide, or you could see later benefits sooner.