GHK-Cu — Peptide Reference

01 — Identity

Name & Classification

GHK-Cu is a naturally occurring copper-binding tripeptide: Glycyl-L-Histidyl-L-Lysine complexed with copper (Cu²⁺). It is an endogenous peptide found in human plasma, urine, and saliva, where it plays a role in tissue repair and maintenance.

Chemical designation: H-Gly-His-Lys-OH · Cu²⁺. It is classified as a copper chaperone peptide and biological wound-healing signal. GHK-Cu activates over 4,000 genes — primarily those related to tissue repair, anti-inflammation, and antioxidant defense — making it one of the broadest gene expression regulators known among small peptides.

Endogenous levels: ~200 ng/mL in young adults, declining to ~80 ng/mL by age 60 — a 60% reduction that correlates with age-related tissue repair decline.

02 — Origin

When It Was Developed

1973

GHK first isolated from human plasma albumin by Dr. Loren Pickart at the University of California San Francisco. Observed to stimulate liver cell function and tissue regeneration.

1970s–80s

Copper complex (GHK-Cu) characterized. Found to stimulate collagen synthesis, wound healing, and skin regeneration. Early cosmetic applications identified.

1990s–2000s

Expanded research revealed GHK-Cu stimulates glycosaminoglycan synthesis, activates metalloproteinases for tissue remodeling, and exhibits anti-inflammatory and antioxidant properties. Widely adopted in cosmetic skincare.

2010s

Gene expression studies by Pickart and Margolina showed GHK-Cu modulates over 4,000 genes — including upregulation of repair genes and downregulation of inflammatory and cancer-related genes. Major longevity and wound-healing implications identified.

2015–Present

Growing use in longevity medicine, injectable protocols, hair loss, wound care, and neuroprotection. Both injectable and topical forms used clinically. Not FDA-approved as a drug; GRAS-status ingredients used in cosmetics.

03 — Research History

Research Background

GHK-Cu's defining characteristic is its extraordinarily broad gene expression profile. A landmark genomic study found it resets the gene expression of aging human skin fibroblasts toward a younger state — upregulating collagen synthesis, antioxidant enzymes (superoxide dismutase, catalase), and DNA repair genes, while downregulating inflammatory NF-κB pathways and genes associated with metastatic cancer.

It acts as both a damage signal and repair orchestrator — released at sites of injury to recruit stem cells, stimulate angiogenesis, and coordinate the healing cascade. Importantly, copper in the GHK-Cu complex is not merely structural — it is required for the biological activity of the peptide and catalyzes critical enzymatic reactions in collagen crosslinking.

Hair follicle research showed GHK-Cu inhibits DHT-related follicle miniaturization, stimulates dermal papilla cell proliferation, and activates Wnt/β-catenin signaling — making it a legitimate candidate for hair loss treatment and scalp regeneration. Neuroprotective studies show promise in ALS, Parkinson's, and TBI models.

04 — Key Benefits

Proposed Benefits

Stimulates collagen and elastin synthesis — skin rejuvenation

Modulates 4,000+ genes toward repair and anti-aging expression

Accelerates wound healing and scar remodeling

Stimulates hair follicle regeneration — hair loss treatment

Potent antioxidant — superoxide dismutase activation

Anti-inflammatory via NF-κB downregulation

Neuroprotective — nerve regeneration support

Recruits stem cells to sites of injury

Stimulates glycosaminoglycan synthesis (joint support)

Resets aging fibroblasts to youthful gene expression

05 — Reconstitution

10 mg Vial + 300 Units BAC Water

33.3 mcg

per unit drawn on insulin syringe

10,000

mcg total

0.3 mL

total volume

4–6 wk

shelf life (fridge)

GHK-Cu is also widely used topically (serums, creams at 0.1–2%) for skin and scalp applications. Injectable form reconstituted with BAC water as above. The copper complex may give a slight blue tint to solution — this is normal. Store refrigerated; protect from light. Do not freeze reconstituted vial.

06 — Dosage

Dosage Reference

Dose	Units / Format	Context
200–500 mcg SC	6–15 u	LOW / INTRO
1–2 mg SC	30–60 u	COMMON
2–3 mg SC	60–90 u	STANDARD
Topical 0.1–2%	Applied to skin/scalp	SKIN / HAIR

Injectable GHK-Cu is typically dosed at 1–3 mg/day SC for systemic regenerative and anti-aging protocols. Topical preparations (0.1–2%) are effective for skin rejuvenation, wound healing, and hair loss — often used concurrently with injectable protocols. GHK-Cu is endogenous and has a very wide safety margin.

07 — Monitoring

Biomarkers, Lab Tests & Ranges

GHK-Cu affects collagen metabolism, inflammation, oxidative stress, and copper homeostasis. Monitor the following before, at 6 weeks, and at cycle end.

▸ Collagen & Skin Biomarkers

Biomarker	Lab Test	Clinical Range	Optimal Range
Procollagen Type I N-terminal (P1NP) Collagen synthesis rate	Serum P1NP	CLINICALM: 20–76 / F: 15–59 µg/L (varies by age)	OPTIMALUpper half of age range; trending up on protocol
Hydroxyproline Collagen degradation marker	Urine Hydroxyproline	CLINICAL15–43 mg/g creatinine	OPTIMALStable or declining (less breakdown)

▸ Copper Homeostasis

Biomarker	Lab Test	Clinical Range	Optimal Range
Serum Copper	Serum Copper	CLINICAL70–140 µg/dL	OPTIMAL90–120 µg/dL
Ceruloplasmin Copper transport protein	Serum Ceruloplasmin	CLINICAL20–60 mg/dL	OPTIMAL25–45 mg/dL
Zinc Cu:Zn ratio balance	Serum Zinc	CLINICAL60–130 µg/dL	OPTIMAL90–110 µg/dL (Cu:Zn ~1:1)

▸ Oxidative Stress & Inflammation

Biomarker	Lab Test	Clinical Range	Optimal Range
8-OHdG Oxidative DNA damage	Urine 8-OHdG	CLINICAL<15 ng/mg creatinine	OPTIMAL<5 ng/mg creatinine
hsCRP	High-sensitivity CRP	CLINICAL<3.0 mg/L	OPTIMAL<0.5 mg/L
SOD Activity Superoxide dismutase	RBC SOD Activity (specialty labs)	CLINICAL1102–1601 U/g Hb	OPTIMALUpper third of range; trending up

▸ Safety

Biomarker	Lab Test	Clinical Range	Optimal Range
AST / ALT	CMP	CLINICALAST 10–40 / ALT 7–56 U/L	OPTIMALAST <26 / ALT <26 U/L
CBC	Complete Blood Count	CLINICALStandard ranges	OPTIMALMid-range; WBC 4.5–6.0

⚠ Monitor copper and zinc balance closely — excess copper supplementation can displace zinc and vice versa. GHK-Cu doses in the injectable range are small relative to total copper status, but copper homeostasis markers should be checked at baseline and mid-cycle. GHK-Cu is not FDA-approved as a drug; widely used in cosmetic formulations.

08 — Cycle Protocol

Cycle Length, Frequency & Timing

▸ How Long to Cycle

SKIN / WOUND HEALING

8–12 Weeks

Injectable cycles of 8–12 weeks align with the natural skin cell renewal cycle (~28 days × 3) needed to see measurable collagen synthesis and skin changes.

LONGEVITY / ANTI-AGING

12–16 Weeks

For systemic anti-aging protocols, 12–16 week cycles with a 4–8 week break. Topical use can be continuous with no cycling requirement.

Topical GHK-Cu (skincare serums) can be used daily indefinitely — no cycling needed. Injectable protocols should cycle to allow copper homeostasis assessment. GHK-Cu is endogenous and well-tolerated; primary risk is copper accumulation with very high doses over very long periods.

▸ Frequency & Timing

Variable	Recommendation	Why
Frequency (injectable)	Daily or 5×/week	Daily or 5 days/week maintains consistent gene expression modulation. Weekend breaks are used by some practitioners for tolerability and copper clearance.
Frequency (topical)	Once or twice daily	AM and/or PM application directly to target areas (face, scalp, wound site). Can be used continuously without cycling.
Fasted vs Fed	~ Either acceptable	GHK-Cu's mechanism is not insulin or glucose-dependent. No meaningful food interaction identified. AM fasted is conventional but not required.
Morning (AM)	✓ Preferred	Morning dosing aligns with circadian repair signaling — collagen synthesis and wound-healing gene expression peak in the morning in most tissues.
Zinc co-administration	⚠ Space by 4+ hours	Copper and zinc compete for absorption. If supplementing zinc, take at least 4 hours away from GHK-Cu injection to avoid antagonism.

PROTOCOL SUMMARY

12–16 wk

CYCLE LENGTH

5–7×

DAYS / WEEK

AM

TIMING

SC / Topical

ROUTE

4–8 wk

BREAK (injectable)