GHK-Cu Peptide: Benefits, safety, dosage, and how it works

Though accepting the passage of time and all that comes with it is an entirely valid choice, you’re far from alone if you’d rather try to fight it — or at least try to reduce its impacts on your physical appearance. In 2024 alone, the global antiaging products market was worth an estimated $52.44 billion, and it’s estimated to grow by nearly 8% from 2025 to 2030.1

As dermaceutical innovation expands, more and more promising products with new active ingredients are being thrust into the spotlight. One such ingredient is GHK-Cu, a copper peptide complex that manufacturers say can do everything from reducing wrinkles and growing hair to fading scars, healing wounds, and more — but is there evidence to back up these claims? In our guide to GHK-Cu, we’ll cover what you need to know about this peptide, including its safety, efficacy, use cases, and everything in between.

Over the past two decades, Innerbody Research has helped tens of millions of readers make more informed decisions involving staying healthy and living healthier lifestyles.

Our team has dedicated thousands of hours over the past few years to learning about a variety of peptides, one of which is the copper peptide GHK-Cu. We’ve spent 40+ hours researching all you need to know about this promising peptide — its origin, uses, safety, efficacy, and more. We also spoke with doctors who are well-versed in peptide therapy to gather valuable information on proper application, side effects, reactions, and contraindications, among other details. Moreover, a member of our team has personally undergone peptide therapy, allowing us to provide information about the patient experience that can only be gained from hands-on experience.

Additionally, like all health-related content on this website, this review was thoroughly vetted by one or more members of our Medical Review Board for accuracy.

GHK-Cu is a complex consisting of the tripeptide GHK (glycyl-histidyl-lysine) and copper (Cu).2 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.2 3 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.4

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 “coincides with the noticeable decrease in regenerative capacity of an organism.”2 This suggests that, for example, lower natural GHK levels may contribute to things like slower wound healing in older adults.5

According to experts, GHK has a “strong affinity for copper” and “readily” 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.3

Most often, you’ll 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:3

• Tighten loose skin
• Reverse age-related skin thinning
• Repair the skin’s 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 “replicative vitality to fibroblasts” (a cell that helps form connective tissue) in patients who’ve undergone radiation therapy for cancer.2 6

To help you better understand how GHK-Cu works, we’ll break down some of the research behind the peptide’s potential applications for hair, skin, and other health aspects.

With all of this in mind, it’s 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, we’ll update this guide accordingly.

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 “has 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.”11 In addition, another piece of research described GHK-Cu as “a safe, inexpensive, extensively studied compound.”3

However, though this is reassuring, there are a couple of things to remain mindful of:

It’s also important to point out that there haven’t been any studies investigating the long-term use of this peptide in humans, so we currently don’t 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, it’s important to first conduct patch testing — as you should with any new topical product.15 Even if GHK-Cu doesn’t cause a reaction, you may still have a sensitivity or allergy to one of the other ingredients in the product you’re using.

If GHK-Cu does happen to cause any adverse reactions, they’re 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 it’s 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 “copper uglies”

Albeit rare, some people may experience a side effect from using GHK-Cu or other copper peptides known as “copper uglies.” Though there aren’t 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 copper's ability to enhance the expression of metalloproteinases (MMPs).16 Now, the degradation of collagen is normally regulated by MMPs, and a specific one, MMP-1, may be responsible for “the initiation of collagen fragmentation.”17 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:18

• 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 “significantly increased gene expression of MMP-1 and MMP-2 at the lowest concentration.” The study’s authors considered this to be one of the reasons the peptide was able to increase collagen and elastin production.19

So, what this could ultimately mean is that using too much GHK-Cu (or other copper peptides) may — in theory — increase the skin’s MMP-1 concentration above the levels involved in healthy collagen production and take it into the “collagen fragmentation and breakdown” territory seen in older skin with naturally higher MMP-1 levels.

Again, the “copper uglies” are rare, but it’s 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 aren’t using multiple copper peptide products all at once.

Based on both the information we learned from knowledgeable medical professionals and what researchers have suggested GHK-Cu has the potential to do, those who’d likely benefit the most from using products containing the peptide include:2 3 4 7

• 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 aren’t bedsores or due to diabetes3
• Those with acne, including cystic acne

When it comes to some of the other potential applications we detailed earlier in this guide — like pain relief and anti-cancer activity — more human research is needed before we can definitively say it should be used by individuals for those purposes. If you’re being treated for pain or cancer, it’s 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).3 14

Who should avoid GHK-Cu?

Because of its history of safe use, there aren’t too many populations that should avoid using GHK-Cu.3 11 However, that doesn’t mean there aren’t any. Those who should reconsider or avoid copper peptides like GHK-Cu include:

• Anyone under the age of 18: We don’t 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 isn’t 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 “feed” tumors. 3 9 14
• Individuals with Wilson’s disease: This rare genetic condition causes copper to build up in your body, so using copper peptides may be dangerous.20

Unlike many other peptide therapies, GHK-Cu typically isn’t administered as an injectable; it’s 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 we’ll primarily be focusing on what it’s like to use GHK-Cu peptides in the form of topicals. As the research on other administration methods develops, we’ll update this information accordingly.

In contrast to certain ingredients, like tretinoin or retinol, GHK-Cu won’t make your skin extra-sensitive to UV rays. In fact, GHK seems to actually block “lethal ultraviolet radiation damage” and protect the skin, per a 2014 study.3 21 This means that GHK-Cu doesn’t 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 — or at different times throughout the day — it’s best to follow the manufacturer’s directions.

To lower the risk of side effects (or to relieve those that may appear), start with a small application and increase gradually over time. It may also help to use a gentle cleanser before applying GHK-Cu and follow it up with a basic, noncomedogenic moisturizer afterward.

Additionally, experts recommend avoiding harsh actives (e.g., retinoids, alpha-hydroxy acids, salicylic acid, etc.), vitamin C, or any active exfoliants while using GHK-Cu peptides. These ingredients could lead to irritation, reduce peptide effectiveness, or compromise the skin barrier.

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.

Unlike most of the other peptides we’ve written about, many of which are more “experimental,” GHK-Cu (often listed as Copper Tripeptide-1) can be found in a multitude of cosmetic products from a wide variety of businesses — both brick-and-mortar and online.

When shopping for a GHK-Cu topical, like a cream or serum, you should make sure the peptide is pure enough to be safe for human use. If you’re ever unsure about a manufacturer’s peptide purity, reaching out to customer service could be a good idea; if they refuse to share this information or other important safety details, it could be a red flag.

If you’re in search of oral or injectable GHK-Cu copper peptides, it’s important to make sure that the clinic you choose uses pharmaceutical-grade peptides, not research-grade ones. The latter is meant to be an experimental material and isn’t held to the same rigorous purity standards as pharmaceutical-grade.23