GHK-Cu, the copper peptide.
What the compound is, why the serum on your shelf and the vial in the fridge are not the same thing, the vial sizes that appear on labels, the unit conversion, storage, and what tracking a GHK-Cu protocol looks like in Protocol Her.
- Compound class
- Copper-binding tripeptide
- In the Protocol Her library as
- GHK-Cu
- Doses entered in
- mg
- A new schedule starts at
- As needed
- Powder vial sizes commonly seen
- 50 mg, 100 mg
Protocol Her shows no reference range for GHK-Cu. Ranges are filled in only where they trace to FDA labeling or a published human trial, and this compound has neither, so the field stays empty rather than being invented.
Three amino acids holding a copper ion.
GHK is a short peptide made of glycine, histidine, and lysine. It occurs naturally in human plasma and binds copper readily, and GHK-Cu is the name for that complex. The Cu is the chemical symbol for copper, which is also why a reconstituted vial is blue.
Two very different products
GHK-Cu is long established as a cosmetic ingredient in topical serums and creams, where it is listed as a percentage of the formula. It is separately sold as research-labeled powder in vials. Same molecule, different products, different routes, and nothing about one transfers to the other.
What preclinical means
The vial form has no approved medical use, no approved label, and no approved indication. Being an established ingredient in cosmetics is not the same as having been reviewed as an injectable medicine, and the app's classification reflects the second, not the first.
What this page will not do
It will not tell you an amount, a schedule, how much water to add, or where to buy anything, and it makes no claim about what GHK-Cu will do for your skin or anything else. Those belong with a clinician. What follows is arithmetic and handling.
Percentages and milligrams.
GHK-Cu is the one compound in this set where you are likely to meet two entirely different labeling conventions, and confusing them is easy.
Topical serums
Cosmetic products state GHK-Cu as a percentage of the formula, typically a fraction of one percent up to a few percent. None of the syringe arithmetic below applies. A percentage in a bottle and a mg total in a vial are not comparable numbers.
Powder vials
Research-labeled GHK-Cu comes as freeze-dried powder, with labels commonly reading 50 mg or 100 mg. Those totals are noticeably larger than a GLP-1 vial, which reflects the scale this compound is worked at, not a stronger product.
Read the mg figure off the vial in front of you every time rather than assuming it matches the last one, and note that larger vials often take more water, which changes the concentration and therefore every number downstream. Protocol Her ships no preset vial sizes and no water volumes for any compound, on purpose.
From mg on the label to units on the barrel.
Take a 50 mg vial with 5 mL of bacteriostatic water added, and say you want to measure 2 mg. Every number here was picked to make the arithmetic easy to follow. None of them is a suggested vial size, water volume, or amount.
Concentration
Divide the peptide in the vial by the water you added. That is the strength of every mL in the finished solution.
50 mg ÷ 5 mL = 10 mg/mL
Volume
Divide the amount you want by the concentration. That gives the volume of liquid holding it. GHK-Cu is entered in mg, so no unit conversion is needed first.
2 mg ÷ 10 mg/mL = 0.2 mL
Syringe units
A U-100 insulin syringe is marked at 100 units per mL, so multiply by 100 to read the same volume on the barrel.
0.2 mL × 100 = 20 units
Note how little of the vial that is: 0.2 mL out of 5 mL means this one vial holds twenty-five such volumes. High-mg vials produce concentrated solutions and correspondingly small readings, which is exactly when a misread mark costs the most. Check the arithmetic rather than eyeballing the barrel.
Run your own numbers in the free calculatorPeptides are fragile proteins.
Heat, light, and agitation are what degrade them, and a copper complex adds a wrinkle of its own. General handling principles below.
- Before mixing, the powder is the stable form. Freeze-dried peptide keeps far better than solution. Store it away from light and heat.
- Blue is expected, not a warning. The color comes from the bound copper, so a reconstituted GHK-Cu solution is blue by nature. What matters is change: a shift from the color it started at, cloudiness, or particles.
- Once liquid is added, it is refrigerated. Reconstituted peptide belongs in the fridge, upright, not in the door where the temperature swings every time it opens.
- Do not freeze a reconstituted vial. Ice crystals damage peptide in solution. Freezing and rethawing is not a way to extend anything.
- Add water gently and do not shake. Run the stream down the inside wall of the vial and swirl slowly. Foaming means agitation, and agitation denatures protein.
- Bacteriostatic water is not sterile water. Bacteriostatic water contains a preservative, benzyl alcohol, which is what allows a vial to be entered more than once. Sterile water has none. They are not interchangeable.
- Write the date you mixed it on the vial. A large vial can sit in the fridge for a long time, which makes the date on the label matter more, not less.
Protocol Her records the date you reconstituted a vial and seeds a discard date 28 days later, a common convention rather than an expiry the app is asserting. The date is yours to change, and the app never claims a beyond-use date on your behalf.
Tracking a GHK protocol, tuned to skin.
GHK-Cu is one of 35 compounds in the app's library, filed under Skin & beauty. That category changes what the app asks you about day to day, and what it declines to fill in.
Skin check-ins and photos
Because GHK-Cu sits in Skin & beauty, the daily card offers a skin-quality check-in and a progress photo prompt, rather than the weight and appetite prompts a metabolic compound brings. Photos stay in the app on your device.
No range, on purpose
Where an approved compound shows a commonly reported range, GHK-Cu shows nothing. The app fills that field only from FDA labeling or a published human trial, so rather than borrow a number from a forum, it leaves the line out entirely.
A schedule that starts empty
A new GHK-Cu schedule opens on As needed rather than a frequency, because people run this compound on widely varied protocols. Pick daily, every other day, twice a week, weekly, or every 2 weeks yourself, then set a time.
The vial, tracked
Log the mg and the water you added and the app carries the concentration forward: doses remaining, a low-stock signal, cost per dose, and the reconstitution and discard dates. Useful here, since a 50 mg vial lasts a while.
One co-factor, with its reasoning
GHK-Cu is one of the few compounds with a compound-specific co-factor note, on zinc. The app shows the reasoning rather than a slogan: the peptide is roughly 16 percent copper by weight, and it says plainly that whether the copper it adds shifts the copper to zinc balance is uncertain.
A record you can hand over
Doses in mg, injection site on the body map, side effects with a 1 to 5 severity, cycle-phase context, and a standing investigational warning. The whole history exports as a clinician-ready PDF.
All of it stays on your iPhone, progress photos included. There is no account and no server copy of what you log, and reminders never name a compound or an amount on your lock screen. What the app leaves blank for GHK-Cu is blank for one reason: no source it trusts, so no number invented.
Common questions, answered.
What does GHK-Cu stand for?
GHK is the three amino acids in the peptide: glycine, histidine, and lysine. Cu is the chemical symbol for copper, which the peptide binds. People shorten it to GHK or call it the copper peptide.
Why is it blue?
The blue comes from the bound copper, so a copper complex in solution is expected to look that way and color alone is not a sign of a problem. A change from the color it started at, or cloudiness or particles, is a different matter.
Is a serum the same as a vial?
No. Topical cosmetics list GHK-Cu as a percentage of the formula and go on skin. Research-labeled vials state a mg total and are a different route entirely. The two numbers are not comparable, and none of the syringe math applies to a serum.
Why are GHK vials so much bigger than GLP-1 vials?
Different compounds work at different scales, so a milligram of one is not comparable to a milligram of another. A 50 mg label next to a 5 mg label says nothing about strength or effect. Compare sema or BPC-157 and the arithmetic is identical while the numbers are nothing alike.
The rest of the library.
Track it where it stays yours.
Protocol Her keeps doses, vials, symptoms, cycle, and labs in one place, with the reconstitution calculator and a live U-100 syringe gauge built in. Free to download, no account to create.
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