GHK-Cu

• Week 1-2: No skin change expected yet; shot may sting
• Week 2-4: Some report smoother, more hydrated skin
• Week 4-8: Users report first skin changes around weeks 4-6
• Week 8-12: Break: some report firmer skin, fewer fine lines
• Side effects: 911 for allergy; yellow skin or eyes: see a doctor; see Side effects

More on each stage

Week 1-2

It is early: skin changes take weeks. Expect some sting or redness where you inject.

Week 2-4

Still early. Some community users say their skin feels smoother or more hydrated within a few weeks.

Week 4-8

Community users report first skin changes (texture, hydration) around weeks 4-6. The store course ends after week 8.

Week 8-12

You are on your 8-week break (weeks 9-16). Judge your skin then. Community users report firmer skin and fewer fine lines at 8-12 weeks, and say hair changes take 3-6 months.

Side effects

Most often stinging, redness, or soreness where you inject; rarely nausea or headache. Stop and get help for swelling of the face or throat, trouble breathing, or a hot, spreading red patch.

Based on what people report in the community sources below. Results vary, and many responses are anecdotal.

• Firmer skin and fewer fine lines (creams)

  Human study

  A review by GHK-Cu's leading researchers reports that cosmetic creams containing it tightened loose skin, improved elasticity, density, and firmness, and reduced fine lines, wrinkles, and sun damage. These results come from creams on the skin.2

• More collagen and elastin

  Animal/lab study

  In lab dishes, GHK-Cu made skin cells (fibroblasts) produce more collagen and elastin, the proteins that keep skin firm and springy.1

• Wound healing (gel)

  Clinical trial

  In a placebo-controlled trial, a GHK-Cu gel helped diabetic foot ulcers close: median closure was 98.5% versus 60.8% with a plain gel.3

• Calms inflammation

  Animal/lab study

  In mice with lung inflammation, GHK-Cu lowered the inflammation signals TNF and IL-6 and reduced lung damage. In rat wounds it lowered TNF.54

• Smoother, more hydrated skin (users)

  Community report

  Community users report better skin texture, firmness, and hydration, and after 3 months or more, thicker hair with less shedding.14

What it has been studied for

• Skin aging: firmness, density, elasticity, fine lines, and wrinkles (cosmetic creams)2Human study
• Diabetic foot ulcers (gel on the wound; helped)3Clinical trial
• Healing of wounds with poor blood flow4Animal/lab study
• Lung inflammation5Animal/lab study
• Hair growth (a close cousin, AHK-Cu, lengthened human hair follicles in a lab dish; GHK-Cu itself has no hair trial)6Animal/lab study

GHK is a tiny peptide your body makes on its own, only 3 building blocks (amino acids) long. It holds on tightly to copper, and the pair is called GHK-Cu. Blood levels fall with age; community sources cite about 200 ng per mL in young adults and about 80 ng per mL in older adults. In lab and animal studies, it tells repair cells to build collagen and elastin, the proteins that make skin strong and stretchy. It also helps rebuild damaged tissue and calms inflammation. Nobody has studied how injected GHK-Cu works in people.

Peak

Not established in humans. No study has measured blood levels after a shot under the skin.

Half-life

Not established in humans. In rats given GHK into a vein, it was quickly broken down into a smaller piece (histidyl-lysine), which also cleared quickly; the study gives no exact time. Enzymes in human blood break GHK down in lab tests.

Cleared

Not established in humans. In rats, GHK was quickly cut down to a two-amino-acid piece (histidyl-lysine), which also left the blood quickly. Each 2.5 mg dose carries up to about 0.4 mg of copper, which joins your body's own copper supply.

Half-life is how long it takes the body to remove half of a dose.7819

Once a day. Morning. Every day (7 days a week). Units are for a 100 mg vial mixed with 2 mL water (50 mg per mL).

• Lower end · conservative entry

  1 mg subcutaneously once daily

  A conservative entry subq dose some start with for collagen and skin-quality support, often 3-5 times per week rather than daily, before settling at the community standard.1416

• Most common · community standard

  1.7-2 mg subcutaneously once daily

  The community-standard subq protocol — 1.7 mg/day is the most-cited anchor dose, injected in the morning and cycled 8 weeks on / 8 weeks off for systemic collagen, skin, and recovery support.1614

• Higher end · advanced; copper caveat

  3 mg subcutaneously once daily

  An advanced subq dose a minority push to for more aggressive tissue-repair goals, still cycled 8 weeks on / 8 weeks off. Copper accumulation is a theoretical concern at this level.16

• Standard protocol

  1.7-2 mg under the skin once a day, in the morning, 8 weeks on and 8 weeks off. 1.7 mg a day is the most-cited dose.16

• Reported range

  1-2 mg under the skin once a day or 3-5 times a week, 4-8 weeks on and 2-4 weeks off. The most common dose is 2 mg a day.14

• Gradual start

  0.5-1 mg a day for days 1-7, 1-1.7 mg a day for days 8-14, then 1.7-2 mg a day from day 15.16

• Higher dose

  3 mg a day, used by a minority. Copper buildup is a theoretical concern at higher or longer use.1614

Research protocols

• Injected GHK-Cu in people

  No human study has tested GHK-Cu shots. Every injected dose below comes from community use, not trials.1611

• Human cosmetic studies

  Creams containing GHK-Cu were put on the skin. The review summary cited here does not give the strength, schedule, or number of people.2

• Human diabetic foot ulcer trial

  A measured amount of GHK-Cu gel on the ulcer every day, starting right after the wound was cleaned, alongside standard wound care.3

• Animal studies (whole-body healing)

  GHK sped wound healing throughout the body, not only where it was applied, in rats, mice, and pigs. The review summary does not give the doses, routes, or schedules.2

Injectable GHK-Cu for cosmetic or systemic use has limited clinical validation. Copper overload is a theoretical concern with high-dose or long-term injection, and product quality varies, especially for injectable preparations.

Dosing guidance built from the cited research and community reports. It is not a prescription.

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On: 8 weeks Break: 8 weeks

A full course at the store pace takes 2 vials. A mixed vial keeps for up to 90 days.

Why the break helps

The 8-week break is a common community habit. Repeated shots could slowly add copper to your body, and the break keeps that in check. It also lets you judge whether your skin changes hold.

Common

• Redness, swelling, or soreness where you inject

  What to do Rotate sites and use a fresh syringe every time. If redness spreads or gets hot and painful, treat it as an infection (see below).

• Stinging or burning after the shot, sometimes for hours

  What to do Inject slowly and rotate sites. If the burn is severe every time, stop.

• Nausea, headache, or tiredness (rare, informal reports)

  What to do Drop to 2 mg (4 units). If it keeps happening, stop.

Stop and get help

• Allergic reaction: hives, swelling of the face, lips, or throat, trouble breathing, or feeling faint. The FDA warns injectable GHK-Cu may trigger the immune system because of clumping and impurities.

  What to do Stop GHK-Cu and call 911 (or your local emergency number) right away.

• Infection at the injection site: redness that spreads, heat, pus, red streaks, or fever

  What to do Stop injecting and see a doctor the same day.

• Possible copper excess: ongoing belly pain, nausea, vomiting, or diarrhea, or yellow skin or eyes

  What to do Stop GHK-Cu and see a doctor. Ask for a blood copper and ceruloplasmin (copper-carrier protein) test.

Do not use if

• You have Wilson disease or another copper-storage disorder, or a liver condition that blocks bile flow (such as biliary cirrhosis): these people should avoid extra copper.
• You know you react to copper.
• You are pregnant, trying to get pregnant, or breastfeeding: there is no safety data.
• You are under 18.
• You compete in a drug-tested sport: GHK-Cu is not named on the WADA list, but WADA's catch-all rule for unapproved drugs (S0) may cover it.

Sources1115

Storage

Keep it

Keep the mixed vial in the fridge (2-8 °C / 36-46 °F), away from heat and light, and never in a hot car.

How long

Use within 90 days of mixing. A mixed vial kept in the fridge holds its strength for 60-90 days, then slowly starts to lose potency. Wipe the rubber top with an alcohol swab before every draw.

Drawing your dose

Syringe: a 0.5 mL (50-unit) U-100 insulin syringe.

1. With this mix, every 1 unit line on a U-100 insulin syringe holds 500 mcg (0.5 mg). Draw to 5 units for the 2.5 mg store dose, 4 units for 2 mg, or 2 units for 1 mg.
2. Some users start lower for the first two weeks (about 0.5-1.7 mg) and build up to the full dose.
3. Hold the syringe at eye level, flick out air bubbles, and push the plunger back to the exact line. Small doses like 5 units are easy to misread, so check twice.
4. Pinch a fold of skin, insert the needle at 45 to 90 degrees, push slowly, and wait a few seconds before pulling out.
5. GHK-Cu shots often sting or burn for a while. Injecting slowly helps.
6. Use a new sterile syringe every time and never share one.

• BPC-157

  GHK-Cu builds collagen and elastin in skin cells, while BPC-157 sped wound healing in animals: two different routes to repair. They are paired in the store's GLOW and KLOW stacks.117

• TB500

  Thymosin beta-4, the protein TB-500 is based on, helps repair cells move into a wound, grows new blood vessels, and reduces scarring. GHK-Cu adds collagen building. They are paired in the store's GLOW stack.18191

• KPV

  KPV turned down the NF-kB inflammation switch and reduced gut inflammation in mice, adding gut and inflammation support to GHK-Cu's skin focus. They are paired in the store's KLOW stack.205

Interactions

• Copper supplements and multivitamins that contain copper

  Each 2.5 mg dose carries up to about 0.4 mg of copper. Adults need about 0.9 mg a day, and the safe upper limit from food and supplements is 10 mg a day. Injected copper skips the gut, and long-term daily shots have not been studied.

  What to do Check your supplement labels and skip extra copper pills unless your doctor says otherwise.

• Copper-lowering treatment for Wilson disease

  GHK-Cu adds copper, which works directly against these treatments.

  What to do Do not use GHK-Cu.

Videos

• The "Glow Stack": BPC-157, TB-500, GHK-Cu & KPVJoy Kong MD · 2026
• Doctor Reacts to Most Powerful Peptide Stacks (GLOW, KLOW, Wolverine)Dr. Jones, DC · 2025
• Benefits & Risks of Peptide Therapeutics (Huberman Lab)Andrew Huberman

Sources

1. 1Pickart & Margolina, Int J Mol Sci 2018 (GHK-Cu skin and gene review)Review
2. 2Pickart et al., Biomed Res Int 2015 (GHK in skin regeneration review)Review
3. 3Mulder et al., Wound Repair Regen 1994 (GHK-Cu gel, diabetic foot ulcers trial)Clinical trial
4. 4Canapp et al., Vet Surg 2003 (rat ischemic wounds)Study
5. 5Park et al., Oncotarget 2016 (mouse acute lung injury)Study
6. 6Pyo et al., Arch Pharm Res 2007 (AHK-Cu and human hair follicles in the lab)Study
7. 7Endo et al., J Chromatogr B 1997 (GHK breakdown in rat plasma)Study
8. 8Dalpozzo et al., Int J Pept Protein Res 1993 (GHK breakdown by human plasma)Study
9. 9PubChem: GHK-Cu (formula and molecular weight, 402.9; copper about 16% by weight)Reference
10. 10Linus Pauling Institute, Oregon State University: Copper (intake limits, Wilson disease, toxicity)Reference
11. 11FDA: Certain bulk drug substances for compounding that may present significant safety risks (GHK-Cu, injectable)Reference
12. 12Goodwin Procter, May 2026: FDA plans to remove injectable GHK-Cu from Category 2 pending an advisory reviewReference
13. 13BSCG: GHK-Cu sport and military rules (WADA S0 catch-all)Reference
14. 14Peptide Protocol Wiki: GHK-Cu community protocols (90 reports)Community
15. 15Peptide Protocol Wiki: GHK-Cu side effectsCommunity
16. 16The Peptide Catalog: GHK-Cu 1.7 mg/day injectable protocolPractitioner
17. 17Seiwerth et al., Front Pharmacol 2021 (BPC-157 wound healing review)Review
18. 18Goldstein et al., Expert Opin Biol Ther 2012 (thymosin beta-4 review)Review
19. 19Esposito et al., Drug Test Anal 2012 (identifies Ac-LKKTETQ in TB-500)Study
20. 20Dalmasso et al., Gastroenterology 2008 (KPV in mouse colitis)Study

Where people discuss it

• r/Peptides (subreddit)
• Peptide Protocol Wiki — GHK-Cu community (90 reports)
• The Peptide Catalog — GHK-Cu injectable protocol

Some peptides, like semaglutide (Ozempic and Wegovy), are FDA-approved medicines. Most of the peptides people research are not. That label sounds like the FDA tested something and turned it down. Usually it means something else: nobody has paid for the studies the FDA needs to see. Here is why.

The FDA doesn’t test drugs. Companies do.

The FDA does not run its own drug tests. A company that wants to sell a new medicine has to test it first, and pay for it. It studies the drug in animals, then in people: first 20 to 100 volunteers, then a few hundred, then up to 3,000. Then it sends all the results to the FDA. FDA scientists review them and decide whether the benefits outweigh the risks.

So approval always starts with a company asking for it. If no company applies, the FDA has nothing to review, however promising the research looks.

Those studies cost about a billion dollars

A study in the medical journal JAMA estimated that bringing one new drug to market costs a typical company about $1.1 billion. That figure includes the money spent on drug ideas that failed along the way, because many drugs that start human testing never make it.

A patent is how a company earns that money back

A patent is a right the government gives an inventor. For up to 20 years from the day the inventor applies, nobody else may make or sell the invention without permission.

For a drug company, that right is what makes the billion-dollar bet worth it. While the patent lasts, the company is the only seller, so it can charge enough to pay back the studies and the failures. When the patent runs out, other companies can sell cheap copies, called generics, and the price drops.

The FDA adds a shorter shield of its own. For 5 years after a brand-new drug is approved, no copycat version can apply for approval. That helps, but it is much shorter than a patent can last.

Why most peptides can’t be patented

To get a patent, an invention has to be new, and it has to be something people made, not something found in nature. Most popular peptides fail one test or both.

They come from nature. Many are copies or small pieces of molecules your body already makes. KPV is a 3-building-block piece of the hormone that tans your skin. BPC-157 is copied from a protein in stomach juice. In 2013 the US Supreme Court ruled that something that exists in nature, like a human gene, cannot be patented just because someone found it and pulled it out.

They aren’t new anymore. Many were first described in research papers decades ago. Scientists were already testing KPV in the 1980s. Once something has been published, it no longer counts as new, so nobody can patent it now, and any patents from back then have long since run out.

Without a patent, a company that paid for the studies would soon face rivals selling the same peptide without having paid for any research. Few companies will spend a billion dollars on a product anyone can copy. So nobody goes first, and the large human studies never happen.

The workaround: change the molecule

Drug companies do make peptide medicines, but they change the peptide first. A changed molecule is a new invention, so it can be patented. Semaglutide is a lab-made version of GLP-1, a gut hormone your body releases after meals, changed so one shot lasts a week. Tesamorelin (Egrifta) is the body’s own growth-hormone signal with a small fatty chain added. Both went through the full studies, and both are FDA-approved.

The natural versions, and the many peptides nobody has changed and patented, stay where they are: studied in labs and animals, used by the biohacking community, and never put through large human trials.

What this means for you

When a peptide is “not FDA-approved,” it usually means no company has paid for the large human studies. It does not mean the FDA tested it and found it harmful.

It also does not mean it is proven safe or proven to work. Without those studies, nobody knows the best dose for sure, or what rare or long-term side effects it may have. And the FDA does not check research peptides for purity or strength the way it checks approved medicines. That is why this page labels every finding by the kind of study behind it, and lists who should not use it.

Sources for this section

1. 1FDA: How drugs are developed and approved (the FDA does not test drugs; companies submit the evidence)
2. 2FDA: The drug development process, step 3: clinical research (study sizes for each phase)
3. 3Wouters, McKee & Luyten, JAMA 2020, corrected 2022: median cost to bring a new drug to market, $1.14 billion
4. 4US patent law, 35 U.S.C. § 154: a patent lasts 20 years from the filing date
5. 5FDA: Frequently asked questions on patents and exclusivity (5-year new chemical entity exclusivity)
6. 6US Supreme Court, Association for Molecular Pathology v. Myriad Genetics (2013): naturally occurring genes cannot be patented