GHK-Cu Dosage Chart: Units, Schedule, Copper Math

The GHK-Cu Dosage Chart

A dosage chart is supposed to summarize what trials settled. For injectable GHK-Cu Explore PeRxGHK-CuThe Skin Rejuvenation PeptideView peptide there is nothing to summarize: the human studies behind the collagen and skin-firmness claims used creams and serums, and no published trial has given GHK-Cu under the skin to people at any dose. So an honest chart has two kinds of rows. The first kind is convention, the ranges clinics and research vendors repeat to each other, which are not wrong so much as unanchored. The second kind is the prescription, a fixed number a licensed physician wrote for a pharmacy-set concentration after screening. The chart below labels which is which.

Read the bottom row first and the top row second. The PeRx figure is not a better guess than the convention rows; it is a different kind of thing, a fixed dose of a fixed concentration that a medical director approved as written and that a pharmacy fills the same way every time. Where it differs from the convention rows is accountability: a prescription has a screening record, a label and a pharmacy behind it, and a Reddit protocol has none of those. For the molecule itself and the evidence behind it, start with the GHK-Cu guide Read nextGHK-Cu Peptide: Benefits, Injections & EvidenceIn 1973, a biochemist at UCSF discovered that young blood makes old cells act young. The molecule responsible was the GHK peptide, a tiny copper-binding tripeptide that drops 60% by age 60 and influences thousands of your genes. Today, TikTok sells it as a $20 face cream. The injectable version does something fundamentally different: it reaches every tissue in your body and signals all of them to start repairing. Here's why that distinction matters more than any skincare trend.Read article ; this page stays on the numbers.

Units on an Insulin Syringe

Every GHK-Cu number online is useless until you know the concentration of the vial in your hand. A U-100 insulin syringe is marked in units, 100 units to the milliliter, and units measure volume, not peptide. The conversion is one line of arithmetic: units equals milligrams divided by the vial strength in mg/mL, times 100. At the 10 mg/mL strength PeRx ships, that collapses to a rule you can hold in your head: every milligram is 10 units. The prescribed 2 mg is 20 units. One milligram would be 10 units, three would be 30. The table runs the common figures at that strength.

The two PeRx blends that contain GHK-Cu are filled at the same 10 mg/mL for the GHK-Cu component, which keeps the arithmetic consistent across the catalog. A 20-unit draw of KLOW carries 2 mg of GHK-Cu alongside 0.6 mg each of BPC-157 Explore PeRxBPC-157The Body Protection CompoundView peptide , KPV and TB-500; the KLOW dosage guide Read nextKLOW Peptide Dosage: Chart, Frequency, CycleNearly every KLOW dosage chart online describes an 80 mg research vial that someone mixes at their kitchen table. The KLOW a physician actually prescribes is a different product with different math. This is the dosing as written on the PeRx prescription: units on the syringe, days per week, weeks per cycle, and what the gray-market charts get wrong.Read article runs all four lines at once. A 20-unit draw of the GHK-Cu/Epitalon Explore PeRxGHK-Cu/EpitalonSkin + Cellular RenewalView peptide vial carries 2 mg of GHK-Cu and 0.4 mg of Epitalon Explore PeRxEpitalonThe Longevity PeptideView peptide . In every case the unit number on your syringe refers to the whole solution, never to one ingredient, and the catalog-wide reference for every PeRx peptide lives in the peptide dosage chart Read nextPeptide Dosage Chart: Doses for Every PeRx PeptideEvery peptide PeRx prescribes, in one dosing reference: route, typical dose, and frequency, with a link to the detailed chart for each. Plus the syringe math that turns milligrams into units, and the reason charts from different pharmacies never quite agree.Read article .

Where the Numbers Come From

GHK-Cu has one of the longest research records of any peptide in compounding, which makes the absence of an injection dose more striking, not less. The tripeptide was identified in human plasma in 1973, and the 1977 paper that named it reported a serum factor that made old liver tissue synthesize protein like young tissue. In 1988 Maquart and colleagues showed the copper complex stimulated collagen synthesis in cultured fibroblasts. What followed was topical: creams and serums tested on facial skin, and the collagen, firmness and wrinkle-depth figures that circulate today come from those studies, which Pickart and Margolina summarize in their reviews.

Schlesinger DH, Pickart L, Thaler MM. "Growth-modulating serum tripeptide is glycyl-histidyl-lysine." Experientia. 1977;33(3):324-325. View study

Maquart FX, Pickart L, Laurent M, Gillery P, Monboisse JC, Borel JP. "Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+." FEBS Letters. 1988;238(2):343-346. View study

Pickart L, Margolina A. "Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data." International Journal of Molecular Sciences. 2018;19(7):2047. View study

Topical doses do not translate into injection doses. A cream delivers a tiny fraction of its GHK-Cu through the skin and the rest stays on the surface; an injection delivers all of it into circulation. Nobody has published the pharmacokinetics of subcutaneous GHK-Cu in people, so there is no measured half-life, no absorption curve and no blood level to target. The one human anchor that exists is the natural one: plasma GHK runs around 200 ng/mL in young adults and falls to roughly 80 ng/mL by age 60, a decline Pickart has used to argue that the peptide matters, but which no injection study has tried to restore to a particular level. The animal work, including the lung-fibrosis and wound models, dosed by body weight in ways that do not convert cleanly to a 20-unit draw.

Pickart L, Vasquez-Soltero JM, Margolina A. "GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration." BioMed Research International. 2015;2015:648108. View study

Pickart L. "The human tri-peptide GHK and tissue remodeling." Journal of Biomaterials Science, Polymer Edition. 2008;19(8):969-988. View study

So where did 1 to 2 mg per injection come from? From practice. Compounding pharmacies had to pick a concentration, prescribers had to pick a volume, and the range that emerged across clinics was scaled from the cosmetic literature and from tolerability rather than from a dose-finding study. That is also why the range is as wide as it is. The PeRx prescription sits at 2 mg because that is the number the prescribing physician and the pharmacy agreed on for a 10 mg/mL fill, and it has stayed fixed since. Treat it as a prescription, which it is, and not as a finding, which it is not. The FDA will eventually weigh in on whether GHK-Cu belongs on the 503A compounding list at all, and the FDA status guide Read nextIs GHK-Cu FDA Approved? Regulatory Status (2026)No. GHK-Cu has never entered clinical trials for injection. But it has been used in topical skincare for over 40 years, and the Broad Institute's Connectivity Map revealed it modulates over 4,000 human genes. GHK-Cu is one of the most extensively researched peptides at the molecular level, with zero clinical trial investment. Here is why.Read article tracks that; a dose is not part of what the committee reviews.

Jiang F, Wu Y, Liu Z, et al. "Synergy of GHK-Cu and hyaluronic acid on collagen IV upregulation via fibroblast and ex-vivo skin tests." Journal of Cosmetic Dermatology. 2023;22(9):2598-2604. View study

When to Inject GHK-Cu

Morning or night is one of the most searched GHK-Cu dosing questions and one of the least consequential. Some peptides carry real timing logic: growth hormone secretagogues are injected before sleep to ride the natural GH pulse, and a breakfast dose wastes the mechanism. GHK-Cu has no equivalent. With no human pharmacokinetics there is no known peak, no circadian behavior and no evidence that an evening dose behaves differently from a morning one. The prescription reflects that by naming a frequency, once daily Monday through Friday, and not a clock time.

What the prescription does ask for is consistency. Pick an hour you can hit five days a week and keep it, because the dose that gets skipped is the one that never found a slot in the routine. Most patients land on the morning for logistics. The one practical argument for a time of day is the injection site: mild redness or a small raised spot at the site is the most common thing people notice, and rotating sites a finger-width apart each day matters more than the hour, which where to inject GHK-Cu Read nextWhere to Inject GHK-Cu: Sites and RotationGHK-Cu goes under the skin, once a day, five days a week. That schedule puts more demand on your rotation habit than a twice-weekly peptide does, and copper brings two handling rules nothing else in the catalog has. Here is how patients actually run it at home.Read article maps out. Food makes no difference to a subcutaneous injection, so fasted-versus-fed rules do not apply, and the broader best time of day Read nextBest Time of Day to Take PeptidesTiming is not the same for every peptide. Growth hormone secretagogues line up with your sleep, cognitive peptides fit the morning, and a few are taken on demand. Here is a practical, category-by-category guide to when each one is usually taken, and why your provider prescribes it that way.Read article guide covers the peptides where timing does matter.

How Long: Cycle and Duration

Most PeRx peptides are written with a scheduled break, some weeks on followed by some weeks off. Standalone GHK-Cu is the exception: it is prescribed for continuous use, Monday through Friday, with no built-in cycle. That means the practical question is not when the cycle ends but when to reassess, and the honest answer is that the first visible changes people report, in skin texture and in how quickly small blemishes settle, tend to arrive over the first several weeks, with firmness changes taking longer. The how long peptides take to work Read nextHow Long Do Peptides Take to Work?Anywhere from the same evening to several months, depending on which peptide and which change you are watching for. PT-141 is dosed for a same-day window while GHK-Cu skin remodeling is a months-long project, and most peptides land somewhere between. This guide maps the typically reported onset windows by peptide family, explains what tends to change first for each goal, and covers why feeling nothing early is often normal rather than a sign of failure.Read article guide sets realistic clocks for the whole catalog.

The cycle changes when GHK-Cu rides inside a blend, because the cycle belongs to the protocol, not to the ingredient. Inside KLOW the same 2 mg per dose runs for 6 weeks and then stops for 6, a rhythm set for the four-peptide repair protocol as a whole. Inside the GHK-Cu/Epitalon vial the schedule follows Epitalon, which is traditionally run in short courses, and the prescription for the combination sets the on and off periods for both peptides at once; the GHK-Cu/Epitalon guide Read nextGHK-Cu + Epitalon: Repair & Longevity Combo GuideOne peptide rebuilds tissue quality at the surface. The other protects the cellular machinery that makes rebuilding possible. GHK-Cu and Epitalon were discovered on different continents, decades apart, by researchers asking completely different questions about aging. The science points to an obvious fit: they cover non-overlapping levels of the same biological problem.Read article walks through why the two are paired. If you move from one of those products to the standalone vial, the rules change with the product. The general logic of breaks, and which peptide classes actually need them, lives in the peptide cycling guide Read nextPeptide Cycling Chart: When to Pause Each ClassPeptide therapy is rarely meant to run forever. Some peptides need scheduled breaks to keep working. Others can be used continuously. The right cycle depends on the peptide class, your goals, and what is happening at the receptor level. Here is the practical guide to cycling, peptide by peptide.Read article .

The Copper Math

The question underneath most GHK-Cu dosing worry is copper. Am I injecting a dangerous amount of a metal? The arithmetic is short. GHK-Cu is one copper ion bound to a tripeptide of about 340 daltons, so copper makes up roughly 16 percent of the complex by weight. A 2 mg dose therefore carries about 0.3 mg of copper. Five doses a week is about 1.6 mg of copper, which averaged over seven days is roughly 0.2 mg per day. The adult recommended dietary intake for copper is 0.9 mg per day and the tolerable upper intake level is 10 mg per day, so the prescribed dose adds about a quarter of a normal daily intake and about 2 percent of the upper limit, and that is the ceiling, assuming every microgram enters the body, which an injection roughly does and a cream does not.

National Institutes of Health, Office of Dietary Supplements. "Copper: Fact Sheet for Health Professionals." Recommended Dietary Allowances and Tolerable Upper Intake Levels for copper. View study

That arithmetic is why copper load is not what screening is for. Screening is for the small number of people whose bodies handle copper abnormally. Wilson disease and the other inherited copper-handling disorders are the clear exclusions, because the problem there is not the amount of copper coming in but the inability to move it out, and any added copper is the wrong direction. Pregnancy, breastfeeding and an active cancer diagnosis are the other standing exclusions on the GHK-Cu prescription. Copper hypersensitivity exists but is rare, and it shows up as skin reactions rather than as systemic toxicity; a site reaction that spreads or persists is the thing to report. The copper in GHK-Cu is chelated, bound to the peptide, which is the form the body transports copper in, and the GHK-Cu guide Read nextGHK-Cu Peptide: Benefits, Injections & EvidenceIn 1973, a biochemist at UCSF discovered that young blood makes old cells act young. The molecule responsible was the GHK peptide, a tiny copper-binding tripeptide that drops 60% by age 60 and influences thousands of your genes. Today, TikTok sells it as a $20 face cream. The injectable version does something fundamentally different: it reaches every tissue in your body and signals all of them to start repairing. Here's why that distinction matters more than any skincare trend.Read article covers that chemistry.

Bandmann O, Weiss KH, Kaler SG. "Wilson's disease and other neurological copper disorders." The Lancet Neurology. 2015;14(1):103-113. View study

Hostynek JJ, Maibach HI. "Copper hypersensitivity: dermatologic aspects." Dermatologic Therapy. 2004;17(4):328-333. View study

What Changes the Dose, and What Does Not

Almost nothing changes it, which is the point of a fixed prescription. Body weight does not: there is no human data from which a per-kilogram GHK-Cu dose could be derived, so the prescribed 20 units is the same for every adult who passes screening. The goal does not either, at least not in any evidence-based way. People reach for GHK-Cu for skin, for hair, for post-procedure recovery and for connective tissue, and vendor pages sometimes assign different milligram figures to each. No study supports a goal-specific injection dose, and the prescription does not pretend to. Day one and day ninety are the same draw. There is no loading phase and no titration, and drawing more units does not speed anything up; it only raises the copper figure above.

Two things do change what you are taking, and both are worth saying out loud. The first is the product. If your GHK-Cu comes inside KLOW or the GHK-Cu/Epitalon vial, the 2 mg is the same but the schedule and the companions are not, and the blend prescription governs. The second is anything added on top. A topical copper-peptide serum is a different route and a different product, and PeRx does not sell one; using one is not a dosing decision about your injection, but it is worth mentioning at screening so the record is complete. Adding a second injectable GHK-Cu product from a research vendor on top of a prescription is not fine-tuning. It combines an unregulated product of unknown content with a prescribed one, and the screening no longer describes what you are injecting.

What should prompt a message to the care team rather than a change you make yourself: a site reaction that spreads beyond a coin-sized area or lasts more than a couple of days, hives, or anything that feels systemic. Routine lab work is not required to start GHK-Cu, and lab work before starting peptides Read nextLab Work Before Starting PeptidesThe honest answer to "what bloodwork do I need before peptides?" is: it depends on the peptide, and for many of them the answer is none. Some sites will tell you to buy a full baseline panel before anything, because they sell the panel. Here is the real picture, which peptides typically need no labs, where a provider may want to check IGF-1 and a metabolic panel, and why the decision belongs to the provider reviewing your history rather than to a checklist.Read article explains which products do need it and why this one does not. The comparison pages, BPC-157 vs GHK-Cu Read nextBPC-157 vs GHK-Cu: Acute Repair vs Tissue RemodelingBPC-157 sends growth factor signals to fix an injury now. GHK-Cu rewrites gene expression to reverse tissue aging over time. One is a first responder. The other is a renovation contractor. They solve fundamentally different problems, which is why some patients use both.Read article and Epitalon vs GHK-Cu Read nextEpitalon vs GHK-Cu: Longevity vs Tissue RepairThey get compared constantly, but they are not competing for the same job. Epitalon is a tetrapeptide studied for the cellular clock: telomeres, telomerase, and melatonin. GHK-Cu is a copper tripeptide that rebuilds visible tissue: skin, hair, and connective tissue. One works on how long your cells can keep dividing. The other works on what those cells actually build. Here is how they differ, when someone considers each, and why the two are often used together rather than either-or.Read article , are the places to decide whether GHK-Cu is the right product in the first place; nothing on this page should be read as a reason to dose your way toward a different goal.

What a Month of GHK-Cu Costs

The standalone GHK-Cu vial is $229 at PeRx. At 20 units per dose a 5 mL vial holds 25 doses, which on a Monday through Friday schedule is five weeks, so the per-dose cost is a little over nine dollars. The vial ships fully reconstituted and ready to use from a state-licensed 503A pharmacy, refrigerated, with insulin syringes and alcohol swabs in the box, and how to store peptides Read nextHow to Store Peptides: Fridge, Travel & Shelf LifeStoring peptides is simpler than most of the internet makes it sound, especially with PeRx. Because every vial ships fully reconstituted and ready to use, there is nothing to mix and no powder to manage. Keep it cold, keep it dark, do not freeze it. Here is the complete answer, product by product.Read article covers keeping it cold and upright for the five weeks it lasts. KLOW, which carries the same 2 mg of GHK-Cu per dose plus three other peptides, is $349 per vial and runs on its own 6-week cycle. The GHK-Cu/Epitalon vial is $299.

GHK-Cu

The PeRx GHK-Cu is an injectable, compounded by a US-based 503A pharmacy at 10 mg/mL in a 5 mL vial, prescribed by a licensed provider after screening. It ships fully reconstituted and ready to use, so the 20-unit draw on the prescription is the only number you need.

Twenty-five doses per vial, Monday through Friday, continuous use. $229 per vial.

One vial, one concentration, one draw. No mixing step and no strength to compute.

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If You Miss a GHK-Cu Dose

The rule is calendar-based. If you remember on the same day, take the dose when you remember. If the day has passed, skip it and take the next scheduled dose on the next dosing day. Never inject twice to catch up: a double draw doubles the copper figure for no documented gain, and one missed weekday out of twenty-five changes nothing worth correcting. Weekends are not missed doses; Saturday and Sunday off is the schedule as written, so Monday is a normal dose, not a make-up.

If you have stopped for several days because something felt wrong, do not quietly restart. A reaction that made you stop is information the care team should have before the next injection. And if the problem is forgetting rather than a reaction, fix the anchor instead of the dose: tie the injection to something you already do at the same time five days a week, and the gaps usually close on their own. New to subcutaneous injections altogether? How to inject peptides Read nextHow to Inject Peptides: Subcutaneous GuideA clear, practical walkthrough of subcutaneous peptide injections, from supply setup to sharps disposal. Written for patients new to self-injection with ready-to-use PeRx vials.Read article covers the mechanics from the first draw.

Common Questions