Side-by-side · Research reference

GHK-CuvsIGF-1 LR3

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

AHuman-MechanisticHUMAN-REVIEWED8/47 cited

BAnimal-StrongHUMAN-REVIEWED10/58 cited

GHK-Cu

Tripeptide · Skin / Hair / Wound Healing

1–2 mgSQ dosePickart 2018

HumanMechanisticPickart 2018 Zink 2003

HoursHalf-life

SQ or topical · Local · Daily or 2-3×/week

IGF-1 LR3

IGF-1 Analogue · Research

3–10×Potency vs IGF-I

Low IGFBPBinding affinity

ResearchStatus

Research only · SQ typical in animal models

01Mechanism of Action

Parameter

GHK-Cu

IGF-1 LR3

Primary target

Copper-dependent enzymes (lysyl oxidase, SOD); regulator of >4000 human genesPickart 2018

IGF-1 receptor (IGF-1R)McTavish 2009

Pathway

Cu(II) delivery via GHK chelation → ↑collagen / elastin / GAG synthesis; ↓inflammatory cytokines; ↑hair follicle growth-factor signalingPickart 2018

IGF-1R → IRS-1 → PI3K/Akt → Cell proliferation, protein synthesis, anti-apoptosisMuhlbradt 2009

Downstream effect

Skin firmness + texture improvement, accelerated wound healing, hair regrowth, anti-inflammatory actionPickart 2018 Zink 2003

Enhanced cell proliferation, muscle anabolism, inhibition of apoptosis, increased telomerase activity

Feedback intact?

Replaces declining endogenous levels

No — exogenous IGF analogue bypasses GH-mediated regulation

Origin

Endogenous tripeptide first isolated from human plasma; declines from ~200 ng/mL at age 20 to ~80 ng/mL at age 60Pickart 2018

Synthetic 83-AA analogue: 13-AA N-terminal extension + Arg substitution at position 3

Antibody development

—

02Dosage Protocols

Parameter

GHK-Cu

IGF-1 LR3

Standard SQ dose

1–2 mg / dayPickart 2018

Anecdotal injectable range; topical creams use 0.1–2% solutions.

—

Topical concentration

0.1–2.0% in serum / cream

—

Frequency

Daily or 2–3× per week (SQ)

—

Lower / starter dose

0.5 mg / day SQ

—

Evidence basis

Human-mechanistic + topical clinical studiesPickart 2018

Animal / in vitro only

Duration

8–12 weeks for visible skin / hair effect

—

Reconstitution

Bacteriostatic water; light-protected

—

Timing

No specific time; evening preferred for topicals

—

Half-life

Hours (estimated; rapid tissue uptake)

—

Research dose (animal models)

—

Variable by protocol and species

In vivo murine atherosclerosis studies used sustained delivery.

In vitro typical concentration

—

10–1000 ng/mLThomas 2007

Dose-dependent effects on follicle growth and estradiol production.

Half-maximal stimulation

—

0.6 nM LR3 vs 1.5 nM native IGF-1Price 2004

2.5-fold greater potency in lung fibroblast proliferation.

Human use

—

Not FDA-approved; no published human trials

03Metabolic / Fat Loss Evidence

Parameter

GHK-Cu

IGF-1 LR3

Mechanism

—

IGF-1R activation → lipolytic signaling; secondary to anabolic effects

Direct lipolytic evidence

—

Minimal — primarily anabolic/anti-apoptotic in literature

Atherosclerotic plaque effects

—

Reduced stenosis and core size in ApoE-KO micevon 2011

Plaque stabilization via vSMC phenotype modulation, not direct fat loss.

Human data

—

None published

04Side Effects & Safety

Parameter

GHK-Cu

IGF-1 LR3

Injection site reaction

Erythema, mild pruritus (common)

—

Topical irritation

Mild redness, transient stinging

—

Copper accumulation

Theoretical with very high chronic doses

—

Allergic reaction

Rare hypersensitivity to copper

—

Pregnancy / OB

Avoid topical and SQ — insufficient data

—

Wilson disease

Contraindicated

—

Hypoglycemia risk

—

Theoretical — IGF-1 analogues can lower blood glucose

Excessive cell proliferation

—

Mitogenic signaling; theoretical tumor promotion risk

Telomerase activation

—

2–10-fold increase in prostate cancer cells (PC-3, DU-145, LAPC-4)Wetterau 2003

Critically involved in cancer cell immortalization.

Oocyte degeneration

—

Increased oocyte degeneration at high doses (≥1000 ng/mL) in bovine folliclesThomas 2007

Unregulated anabolism

—

Bypasses physiological GH/IGF-1 feedback; no pulsatility control

Unknown human safety profile

—

No published human trials; safety data absent

Absolute Contraindications

GHK-Cu

·Wilson disease (copper-overload disorder)
·Pregnancy / breastfeeding
·Known copper hypersensitivity

IGF-1 LR3

·Active malignancy or history of cancer
·Not approved for human use

Relative Contraindications

GHK-Cu

·Hemochromatosis (copper-iron crosstalk theoretical)
·Concurrent copper-chelator therapy

IGF-1 LR3

·Diabetes or glucose intolerance
·Family history of cancer

05Administration Protocol

Parameter

GHK-Cu

IGF-1 LR3

1. Reconstitution

Add 1–2 mL bacteriostatic water to a 50 mg vial → 25–50 mg/mL. Use within 30 days, refrigerated.

IGF-1 LR3 is not FDA-approved for human use. All administration data derives from animal or in vitro studies.

2. Injection site

SQ — local to the area of interest (face, scalp) for skin / hair indications. Rotate sites.

Subcutaneous or intraperitoneal injection in animal models. In vitro: added directly to culture medium at concentrations of 10–1000 ng/mL.Thomas 2007

3. Timing

Anytime; evening preferred. Topical: apply to clean dry skin.

Lyophilised powder reconstituted in sterile water or buffered saline per manufacturer protocol. Store at 2–8 °C after reconstitution.

4. Storage

Lyophilised: room temp, light-protected. Reconstituted: refrigerate, light-protected, ≤30 days.

Enhanced stability vs native IGF-1 due to reduced IGFBP binding; exact half-life in vivo not fully characterized in humans.

5. Needle

30–31G, short (4–6 mm) for shallow SQ. Topical: clean fingertips, no needle.

—

06Stack Synergy

GHK-Cu

+ BPC-157

Moderate

View BPC-157 →

GHK-Cu drives ECM remodelling and copper-dependent enzymes; BPC-157 upregulates VEGFR2 angiogenesis and fibroblast migration. The pathways are non-overlapping and complementary — together they accelerate wound healing more than either alone in anecdotal protocols.

GHK-Cu: 1–2 mg SQ · daily near wound
BPC-157: 250–500 mcg SQ · daily near wound
Primary benefit: Combined ECM rebuilding + angiogenesis for tissue repair

IGF-1 LR3

+ GHRP-6

Multi-pathway

View GHRP-6 →

GHRP-6 stimulates endogenous GH release, which drives hepatic IGF-1 synthesis. IGF-1 LR3 provides exogenous, IGFBP-resistant IGF signaling. Combining upstream GH stimulation with downstream IGF receptor activation creates a dual-pathway anabolic effect. However, this bypasses natural feedback and carries compounded mitogenic risk.

GHRP-6: 100–200 mcg SQ · 2–3× daily
IGF-1 LR3: Research doses variable · post-workout typical in animal models
Note: Research context only — no human protocols exist
Primary benefit: Theoretical maximal anabolic signaling (GH + IGF axes)

+ Ipamorelin

Multi-pathway

View Ipamorelin →

Ipamorelin (selective GHRP) stimulates pulsatile GH release without cortisol/prolactin elevation. IGF-1 LR3 directly activates IGF-1R independent of GH. This stack targets both upstream (GH secretion) and downstream (IGF receptor) nodes but eliminates physiological feedback, raising safety concerns around unchecked proliferation.

Ipamorelin: 200–300 mcg SQ · evening
IGF-1 LR3: Research doses only · timing variable
Caution: No human data; animal/in vitro only
Primary benefit: Dual-axis anabolic signaling (theoretical)