Side-by-side · Research reference

AHK-CuvsHumanin

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-REVIEWED14/52 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

Humanin

Mitochondrial-Derived Peptide · Cytoprotective

24-AAPeptide lengthZhu 2022

mtDNAEncoded originZhu 2022 Shahzaib 2026

Bax/BimPrimary targetZhu 2022 Morris 2021

SQ · Experimental

01Mechanism of Action

Parameter

AHK-Cu

Humanin

Primary target

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

Intracellular: Bax, Bim, tBid (pro-apoptotic Bcl-2 family). Extracellular: FPRL1/2 G-protein-coupled receptorsZhu 2022 Lue 2021

Pathway

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

Humanin binds Bax/Bim → inhibits mitochondrial outer membrane permeabilization (MOMP) → blocks cytochrome c release → prevents caspase activation → cell survival

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

Suppression of apoptosis, mitochondrial stabilization, reduced oxidative stress, preservation of germ cells and neurons under stressZhu 2022 Lue 2021 Velentza 2024

Feedback intact?

—

Not applicable — peptide acts as anti-apoptotic signal, not hormonal axis

Origin

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

Encoded by short open reading frame in mitochondrial 16S rRNA gene (MTRNR2). 24-28 amino acids. 13 homologous variants (MTRNR2L1-L13) identified.Zhu 2022 Shahzaib 2026

Antibody development

—

Not reported in animal models

02Dosage Protocols

Parameter

AHK-Cu

Humanin

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)

Daily (IP)

Route

Topical — scalp or dermal application

—

Evidence basis

Ex vivo hair follicle / in vitro DPC studiesPyo 2007

Animal models (rat, mouse)Huang 2025 El 2022 Velentza 2024

Duration

Not established — cosmetic protocols typically 8–12 weeks

8–12 weeks in animal studies

Standard experimental dose (HNG)

—

4 mg/kg IP (rat)

Most common dose in rodent models.

Ex vivo bone culture

—

1 µg/mL

Protective against venetoclax-induced bone growth retardation.

Human data

—

None — no clinical trials reported

Analog (HNG)

—

Gly[14]-humanin — more potent variant

Substitution at position 14 enhances cytoprotective activity.

03Metabolic / Fat Loss Evidence

Parameter

AHK-Cu

Humanin

Direct fat loss evidence

—

None

Mechanism overlap

—

Mitochondrial health may indirectly influence metabolic efficiency, but no quantified effect

04Side Effects & Safety

Parameter

AHK-Cu

Humanin

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)

—

Animal model safety

—

Well-tolerated in rat and mouse studies at 4 mg/kg for 8–12 weeks

Human safety data

—

None — no clinical trials

Theoretical fibrillation risk

—

Induces amyloid-like fibrillation of Bax/BID. Long-term sequelae unknown.

Injection site reaction

—

Not reported in animal studies (IP route)

Reproductive safety

—

Protective in POI model (cyclophosphamide-induced), no adverse effects on fertility notedHuang 2025

Absolute Contraindications

AHK-Cu

·Known copper allergy or Wilson's disease

Humanin

·Unknown — no human data

Relative Contraindications

AHK-Cu

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

Humanin

·Active malignancy (theoretical risk of anti-apoptotic effect on tumour cells)

05Administration Protocol

Parameter

AHK-Cu

Humanin

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.

Intraperitoneal (IP) in animal models. Subcutaneous route untested. No human protocols exist.

2. Frequency

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

Synthetic peptide reconstituted in sterile saline or PBS. No commercial formulation available.

3. Scalp preparation

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

Daily administration in animal studies. Optimal timing not characterized.

4. Storage

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

Lyophilised powder: -20 °C. Reconstituted: 4 °C, use within 7 days. Avoid freeze-thaw cycles.

5. Duration

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

No FDA approval, no IND, no clinical trials. Experimental research tool only.

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

Humanin

+ MOTS-c

Multi-pathway

View MOTS-c →

Both are mitochondrial-derived peptides. MOTS-c enhances metabolic efficiency and insulin sensitivity via AMPK activation, while humanin prevents mitochondrial apoptosis. Combined, they address mitochondrial function (MOTS-c) and survival signaling (humanin), supporting cellular resilience under metabolic and oxidative stress.

Humanin: 4 mg/kg IP · daily (animal model)
MOTS-c: 5 mg/kg IP · daily (animal model)
Frequency: Once daily
Primary benefit: Mitochondrial health, metabolic efficiency, anti-apoptotic signaling