Side-by-side · Research reference

AHK-CuvsIGF-1 LR3

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

AAnimal-MechanisticHUMAN-REVIEWED14/43 cited

BAnimal-StrongHUMAN-REVIEWED10/58 cited

AHK-Cu

Tripeptide-Copper Complex · Cosmetic

10⁻¹² – 10⁻⁹ MActive range (in vitro)Pyo 2007

Dermal papilla cellsPrimary targetPyo 2007

TopicalRoute

Topical · Scalp / Skin

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

AHK-Cu

IGF-1 LR3

Primary target

Dermal papilla cells (DPCs) — specialized fibroblasts in hair follicle morphogenesisPyo 2007

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

Pathway

AHK-Cu → DPC proliferation → VEGF elevation, TGF-β1 suppression → Angiogenesis, follicle elongationPyo 2007

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

Downstream effect

Stimulates hair follicle elongation ex vivo, reduces dermal papilla cell apoptosis, elevates Bcl-2/Bax ratio, reduces cleaved caspase-3 and PARPPyo 2007

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

Feedback intact?

—

No — exogenous IGF analogue bypasses GH-mediated regulation

Origin

Synthetic tripeptide with Cu²⁺ chelation — alanine substitution variant of GHK-Cu

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

Antibody development

—

02Dosage Protocols

Parameter

AHK-Cu

IGF-1 LR3

Effective concentration (in vitro)

10⁻¹² – 10⁻⁹ MPyo 2007

Stimulated human hair follicle elongation ex vivo and DPC proliferation in vitro.

—

Topical formulation

0.001–0.01% (estimated cosmetic range)

No standardized human protocol published — extrapolated from in vitro data.

—

Frequency

Once or twice daily (topical application)

—

Route

Topical — scalp or dermal application

—

Evidence basis

Ex vivo hair follicle / in vitro DPC studiesPyo 2007

Animal / in vitro only

Duration

Not established — cosmetic protocols typically 8–12 weeks

—

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

AHK-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

AHK-Cu

IGF-1 LR3

Local irritation

Mild erythema, pruritus at application site (copper peptide class effect)

—

Copper sensitivity

Rare hypersensitivity reaction in copper-sensitive individuals

—

Systemic absorption

Minimal via topical route — systemic copper toxicity unlikely at cosmetic doses

—

Data limitations

No published human safety trials — cosmetic use presumed safe per class precedent (GHK-Cu)

—

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

AHK-Cu

·Known copper allergy or Wilson's disease

IGF-1 LR3

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

Relative Contraindications

AHK-Cu

·Broken or inflamed skin (increased absorption risk)
·Concurrent use of other copper-containing formulations

IGF-1 LR3

·Diabetes or glucose intolerance
·Family history of cancer

05Administration Protocol

Parameter

AHK-Cu

IGF-1 LR3

1. Topical application

Apply to clean, dry scalp or target dermal area. Typical cosmetic formulations: 0.001–0.01% AHK-Cu in serum or cream base.

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

2. Frequency

Once or twice daily. Evening application preferred for overnight contact time.

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

3. Scalp preparation

For hair growth: apply directly to scalp, massage gently. No need to rinse. Allow absorption for minimum 2–4 hours.

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

4. Storage

Room temperature, protected from light. Copper complexes may degrade in UV exposure.

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

5. Duration

Minimum 8–12 weeks to assess efficacy in hair growth applications, per typical cosmetic peptide protocols.

—

06Stack Synergy

AHK-Cu

+ GHK-Cu

Moderate

View GHK-Cu →

Both tripeptide-copper complexes share overlapping angiogenic and wound-healing mechanisms (VEGF elevation, TGF-β modulation, fibroblast proliferation). AHK-Cu's alanine substitution may offer distinct receptor affinity or pharmacokinetics. Co-formulation could provide complementary dermal signaling, though no direct synergy studies exist. Often used interchangeably or in alternating protocols.

AHK-Cu: 0.001–0.01% topical · AM
GHK-Cu: 0.001–0.01% topical · PM
Frequency: Daily alternation or combined formulation
Primary benefit: Comprehensive dermal regeneration, angiogenesis, hair follicle support

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)