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Animal data onlyNot FDA approved

AHK-Cu

Also known as: Copper tripeptide-3 · AHK copper · Alanyl-histidyl-lysine copper · L-Alanyl-L-histidyl-L-lysine-Cu2+ · Ala-His-Lys-Cu

Updated 26 sources

A copper tripeptide, alanine, histidine, lysine, sold for thinning hair. It is GHK-Cu with one amino acid swapped. The evidence is one 2007 lab study on human hair follicles and a mouse patent; no human trial exists. Most people use it as a scalp serum, and injected doses are borrowed from GHK-Cu.
Calculate with AHK-CuDosage chart

Quick facts

Half-life
  • Not established. Free AHK is reportedly cut by blood enzymes within minutes; on the skin it is thought to act locally.
  • About 1 to 2 hours by one guide's estimate, extrapolated from GHK-Cu; no AHK-Cu study exists.
Routes
  • Topical
  • Subcutaneous injection
  • Other route
Forms
  • Topical
  • Vial (powder)
Reported dose ranges
  • 0.4 to 5% (topical)
  • 50 to 500 mcg (subcutaneous injection)
  • 1 to 5 mg (subcutaneous injection)
  • 0.1 to 0.5 mg (other route)
Vial sizes
  • 5 mg, 10 mg, 50 mg, 100 mg
Chemistry
  • 415.93 g/mol · C15H24CuN6O4 · CAS 767286-83-9
FDA status
  • Not FDA approved
WADA
  • Not confirmed

What people use AHK-Cu for

  • Thinning scalp hair and shedding, as a leave-on serum
  • Added to minoxidil, finasteride or dutasteride routines
  • Paired with GHK-Cu in one serum, or topical AHK-Cu with injected GHK-Cu
  • Microneedling the scalp before applying a sterile serum
  • Injected under the skin by a minority, dosed like GHK-Cu

How it is thought to work. Delivers copper to the hair follicle. In lab work it lengthened human follicles and grew dermal papilla cells, raised the Bcl-2/Bax ratio and cut cleaved caspase-3, which points to less cell death. Guides add raised VEGF and a longer growth phase, drawn partly from GHK-Cu research. All of this is cell and follicle work, not human trials.

AHK-Cu dosing

11 protocols from studies, guides and community reports, grouped by goal. Tap a source badge to see where a number came from.

Topical, topical5

Scalp serum

Amount
0.5 to 1%
How often
4 to 6 drops on clean, dry scalp, once or twice daily
Route
Topical, topical
Timing and details

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Hair growth serum

Amount
0.5 to 1%
How often
Once or twice daily
Route
Topical, topical
Cycle
12 to 24 weeks minimum for hair, then ongoing for maintenance

Stronger serum

Amount
2 to 5%
How often
Once or twice daily as a leave-in
Route
Topical, topical
Timing and details

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Community DIY serum

Amount
0.4 to 2%
How often
Daily
Route
Topical, topical
Timing and details

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Copper peptide blend serum

Amount
1%
How often
Daily
Route
Topical, topical
Timing and details

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Injected5

Injected titration

Amount
250 to 500 mcg
How often
Once daily
Route
SubQ, vial (powder)
Cycle
12 weeks or more
Titration (3 steps) and details

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Injected microgram tiers

Amount
100 to 500 mcg
How often
Once daily
Route
SubQ, vial (powder)
Cycle
8 to 12 weeks on
Rest
4 weeks off
Timing and details

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Low injected dose

Amount
50 to 200 mcg
How often
Daily
Route
SubQ, vial (powder)
Timing and details

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Research protocol

Amount
1 to 5 mg
How often
2 to 3 times a week
Route
SubQ, vial (powder)
Cycle
12 to 24 weeks minimum for hair
Timing and details

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Dosed like GHK-Cu

Amount
1 to 3 mg
How often
Daily
Route
SubQ, vial (powder)
Timing and details

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Other, vial (powder)1

Scalp mesotherapy

Amount
0.1 to 0.5 mg
How often
Weekly sessions, amount per injection site
Route
Other, vial (powder)
Timing and details

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Doses shown are what sources report, labelled by origin. Not medical advice.

Full AHK-Cu dosage guideEvery titration step in syringe units, missed doses and how to mix.

Vial strengths and syringe units

Every AHK-Cu vial size with the water volumes sources use. Units are what to draw on a U-100 insulin syringe, worked out exactly.
AHK-Cu: concentration and U-100 syringe units for each vial size and water volume
WaterStrength250 mcgdose, units500 mcgdose, units1 mgdose, units
5 mg vial
1 mLCompetitor guide5 mg/mL50.05 mL100.1 mL200.2 mL
10 mg vial
2 mLCompetitor guide5 mg/mL50.05 mL100.1 mL200.2 mL
50 mg vial
3 mLCommunity-reported16.667 mg/mL1.50.015 mL30.03 mL60.06 mL
All 4 vial sizes on the dosage chart (1 more)
Units are on a U-100 insulin syringe (100 units = 1 mL). U-50 and U-30 barrels read the same units.† Water volume sourced for a different vial size. The math is exact either way.Water volumes from

Doses shown are what sources report, labelled by origin. Not medical advice.

Calculate with this peptideYour vial, your water, your dose: AHK-Cu in syringe units, with the math shown.

AHK-Cu side effects

What trials and labels report, kept apart from what users and guides report. Frequencies are worded as each source states them.

Reported by users and guides6

From community reports and dosing guides. Not measured rates.

  • Mild redness, stinging or itching

    On the skin; guides call topical use generally well tolerated

  • Blue-green tint on hair, skin or fabric

    Passing; from the copper

    How people manage it

    • Wash the hair well; one user only sees the sheen when they skip it

  • Allergic contact dermatitis

    Possible, especially with copper or nickel sensitivity

  • Shedding in the first weeks

    Called rare by one guide, usually settling by weeks 6 to 8; one r/tressless user on an 8% blend saw shedding climb at 7 weeks

    How people manage it

    • The guide says stop if heavy shedding lasts past week 8 or comes with scalp irritation

  • Pain, itch and soreness after injecting

    One r/Biohackers user

  • Hair growth outside the scalp

    A worry raised in threads about injecting; users report it with injected GHK-Cu and ask about it on the face

    How people manage it

    • Users who want scalp-only effects keep it topical
All 7 AHK-Cu side effects and how people manage themEvery management tip, who should not use it, and side-effect questions.

Who should avoid it

  • Wilson's diseaseCondition

    A copper storage disorder; guides say avoid copper peptides.

  • Copper-chelating drugs (penicillamine, trientine)Substance

    Listed by a guide as a reason to avoid.

  • High-dose zincSubstance

    One guide says avoid zinc above 50 mg a day, since zinc and copper compete.

  • High-strength vitamin C at the same timeSubstance

    Guides say apply at a different time, for example vitamin C in the morning and AHK-Cu at night.

  • Broken or infected skinCondition

    One guide says avoid broken or infected skin and the area near the eyes.

  • Pregnancy and breastfeedingCondition

    Unstudied.

Storage

Powder (before mixing)

Temperature
-20 °C

Freezer at -20 C, away from light. Keeps 1 year or more; one guide says up to 2 years.

Powder (before mixing)

Temperature
2 to 8 °C

Fridge at 2 to 8 C for 1 to 3 months. Room temperature only in a pinch, 2 to 3 weeks.

Mixed vial

Temperature
2 to 8 °C
Use within
28 to 30 days

Fridge at 2 to 8 C, dark. Most guides say about 4 weeks to 30 days. Never refreeze.

Mixed vial

Temperature
2 to 8 °C
Use within
14 to 21 days

Stricter guides: 14 to 21 days in the fridge. Discard if the colour changes or particles appear.

Mixed vial

Temperature
2 to 8 °C
Use within
30 days

Homemade topical serum: fridge at 2 to 8 C in dark glass, use within 30 days. Copper peptides oxidize with light and air.

Mixed with: Bacteriostatic water

Mixing. Injection vials hold too little for a scalp serum; topical users buy raw cosmetic powder by the gram instead. Raw powder is not sterile, so it is not for injection or microneedling. One guide warns that a 50 mg vial in 2 mL is too concentrated for microgram doses: 100 mcg would be 0.4 units, too small to measure.

Stacks people report

Combinations from guides and community posts, with the reason given.
  • GHK-Cu

    The most common pairing: both in one scalp serum (for example 1% AHK-Cu with 6% GHK-Cu), or topical AHK-Cu with injected GHK-Cu. Guides call it a complementary copper peptide.

  • BPC-157

    Listed by one guide as compatible; the benefit is described as theoretical.

Compare AHK-Cu

Evidence and legal status

Evidence: animal data only

Lab and animal only. Pyo 2007: AHK-Cu at 10^-12 to 10^-9 M lengthened human hair follicles ex vivo and grew dermal papilla cells; the drop in cell death was not significant. A 1994 ProCyte patent reports mouse intradermal injections. No published human trial. One registered geroprotection study (NCT07888595, enrolling by invitation) includes AHK-Cu in a multi-peptide topical serum; no results yet.

FDA and WADA

Not FDA approved

No approval, no trial program and not on FDA's compounding lists.

Not an approved drug. Sold as a cosmetic ingredient and research chemical. Not on FDA's 503A bulk substance lists (May 14, 2026 update). Under FDA rules a product claiming to restore hair growth is a drug, not a cosmetic.

Not named on the WADA 2026 Prohibited List. S0 covers pharmacological substances with no therapeutic approval; no source addresses AHK-Cu.

WADA: Not confirmed

AHK-Cu questions

What is AHK-Cu?

A copper complex of the tripeptide alanine, histidine, lysine, sold as copper tripeptide-3. It is GHK-Cu with one amino acid swapped and is marketed for scalp and hair.

AHK-Cu vs GHK-Cu: what is the difference?

One amino acid: alanine instead of glycine. GHK-Cu has decades of research and some human skin trials. AHK-Cu has one 2007 lab study on human hair follicles and cells. AHK-Cu is sold for hair, GHK-Cu for skin and repair.

What strength do people use on the scalp?

Guides give 0.5 to 1% once or twice daily, or 2 to 5% for stronger serums. On r/Peptides, DIY mixes run 0.4 to 2%. Blends pair it with GHK-Cu, such as 1% AHK-Cu with 6% GHK-Cu.

Can you inject AHK-Cu?

Some people do, but no study backs a dose. One guide that prints an injection schedule says no validated injectable protocol exists. Many r/Peptides replies say keep it topical; those who inject copy the GHK-Cu dose.

What is the injected dose?

Published numbers range from 50 mcg to 5 mg, a 100 fold spread: 50 to 200 mcg daily, 100 to 500 mcg daily (reported as community consensus), 250 to 500 mcg titrated over 12 weeks, or 1 to 5 mg two to three times a week. Users who inject usually copy GHK-Cu at 1 to 2 mg a day.

How much water for a vial?

Guides use 2 mL for 10 mg (5 mg/mL) or 1 mL for 5 mg (5 mg/mL). One guide warns that a 50 mg vial is too concentrated for microgram doses; one r/Peptides user mixed a 50 mg vial with 3 mL.

Can I make a serum from an injection vial?

Users do, but r/Peptides members point out that vial doses are tiny for topical use. Raw cosmetic powder sold by the gram is cheaper; a 1% serum is 1 g in 100 mL. Raw powder is not sterile, so do not inject or microneedle with it.

How long until hair results show?

One guide says 12 to 24 weeks minimum. In r/tressless progress threads, commenters say to wait at least 6 months before judging.

Does AHK-Cu cause shedding?

One guide calls early shedding rare and says it usually settles by weeks 6 to 8. One r/tressless user on a 4% AHK-Cu plus 4% GHK-Cu serum reported shedding rising at 7 weeks; another user said they never had it.

Will it turn my hair blue?

It can leave a passing blue-green tint on hair, skin or fabric. One user sees a sheen only when they do not wash it out well.

Can I use it with minoxidil?

Yes, at a different time of day: minoxidil in the morning and AHK-Cu at night is the common split. Many users also run finasteride or dutasteride.

Can I use it with vitamin C?

Not at the same time. Guides say high-strength vitamin C should go on at a different session, morning versus evening.

Can I use it with microneedling?

People do, with a sterile serum. One guide says no more than once a week; one user needles weekly and applies AHK-Cu daily.

Are there human studies?

No published human trial of AHK-Cu exists. The key study, from 2007, found it lengthened human hair follicles in a dish and grew dermal papilla cells at very low concentrations. A 1994 ProCyte patent describes injections in mice.

Who should avoid it?

People with Wilson's disease, a copper disorder. Guides also say avoid copper chelating drugs and very high zinc, and note pregnancy and breastfeeding are unstudied.

Is AHK-Cu FDA approved?

No. It is sold as a cosmetic ingredient and a research chemical and is not on FDA's 503A bulk drug lists. Under FDA rules, a product claiming to restore hair growth counts as a drug, not a cosmetic.

Ask about AHK-Cu

Answers come from this site's pages only, with a link to each source.

Sources

26 sources, each checked by date. Record updated Oct 24, 2026. Numbers are restated in our own words and labelled by where they came from.

Vendor guide2

  1. AHK-Cu dosage guideVendor guide · checked Oct 24, 2026
  2. Copper tripeptide-3 datasheet (HY-P5243)MedChemExpress · checked Oct 24, 2026

Competitor guide7

  1. AHK-Cu dosage guide and calculatorpeptideschedule.com · checked Oct 24, 2026
  2. AHK-Cu dosage chart, schedule and reconstitution protocolpeptidedosage.org · checked Oct 24, 2026
  3. AHK-Cu: how it works, mechanism and evidencethepeptidecatalog.com · checked Oct 24, 2026

Community-reported11

  1. Question in AHK-CU (2026-09-29)r/Peptides · checked Oct 24, 2026
  2. Has anybody tried injectable AHK-Cu for hair? (2026-07-16)r/Peptides · checked Oct 24, 2026
  3. AHK-cu (2025-10-12)r/Peptides · checked Oct 24, 2026