AHK-Cu (Alanine-Histidine-Lysine Copper) vs GDF-11 (Growth Differentiation Factor 11)
A neutral, side-by-side comparison of two anti-aging & longevity peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
AHK-Cu (Alanine-Histidine-Lysine Copper)
Copper-chelating tripeptide structurally related to GHK-Cu but optimized for scalp and hair follicle applications. AHK-Cu activates hair follicle stem cells and prolongs the anagen (active growth) phase, making it a key research compound for androgenetic alopecia and diffuse hair loss. Used topically as an alternative or complement to minoxidil and finasteride.
Full profileGDF-11 (Growth Differentiation Factor 11)
TGF-β superfamily member proposed as a 'young blood factor' — circulating GDF-11 declines with age, and young plasma transfusion in parabiosis experiments reversed aging phenotypes in mice. A high-profile but contested research area: some studies show rejuvenating effects in heart, muscle, and brain; others using purified recombinant GDF-11 show cardiac hypertrophy and muscle wasting at pharmacologic doses.
Full profile| AHK-Cu (Alanine-Histidine-Lysine Copper) | GDF-11 (Growth Differentiation Factor 11) | |
|---|---|---|
| Category | Anti-Aging & Longevity | Anti-Aging & Longevity |
| Also known as | AHK copper peptide, Ala-His-Lys copper, hair growth copper peptide, AHK-copper complex | GDF11, Bone Morphogenetic Protein 11, BMP-11, young blood factor |
| Evidence | Research-stage | Research-stage |
| Dosing range | 0.1%–1% %, Daily topical application (scalp) | 0.1mg/kg–1mg/kg mg/kg, every 3–7 days (SC); research protocols vary widely |
| Administration | Topical (scalp serum/solution), Subcutaneous (microneedling-assisted delivery) | Subcutaneous injection, Intravenous (research) |
| Key side effects | Mild scalp irritation, Contact dermatitis (rare), Temporary scalp redness or tingling, Transient scalp shedding at initiation (shedding phase) | Cardiac hypertrophy (at pharmacologic doses — the key safety concern), Muscle wasting and weight loss, Reproductive effects (GDF-11 inhibits spermatogenesis and folliculogenesis), Cachexia-like syndrome at high doses |
| Cited sources | 2 references | 2 references |
Key differences
- Administration: AHK-Cu (Alanine-Histidine-Lysine Copper) — Topical (scalp serum/solution), Subcutaneous (microneedling-assisted delivery); GDF-11 (Growth Differentiation Factor 11) — Subcutaneous injection, Intravenous (research).
- Dosing units differ: AHK-Cu (Alanine-Histidine-Lysine Copper) is dosed in %, GDF-11 (Growth Differentiation Factor 11) in mg/kg — they operate at different scales.
- Frequency: AHK-Cu (Alanine-Histidine-Lysine Copper) is typically Daily topical application (scalp); GDF-11 (Growth Differentiation Factor 11) is every 3–7 days (SC); research protocols vary widely.
How each works
AHK-Cu (Alanine-Histidine-Lysine Copper)
AHK-Cu activates β-catenin/Wnt signaling in dermal papilla cells and promotes VEGF expression around hair follicles. Studies demonstrate extended anagen phase duration, increased follicle size, and upregulation of hair growth factors in treated scalp tissue. The copper component supports tyrosinase activity for follicle pigmentation and metalloenzymes involved in extracellular matrix remodeling around follicles.
GDF-11 (Growth Differentiation Factor 11)
The 2013–2014 parabiosis studies from Amy Wagers' lab at Harvard proposed GDF-11 as the primary rejuvenating factor in young blood. However, subsequent work by Lee and others showed that purified recombinant GDF-11 at pharmacologic doses caused cardiac hypertrophy, muscle atrophy, and weight loss — opposite of the proposed rejuvenating effects. The field now views GDF-11 as highly dose-sensitive with a narrow therapeutic window, if one exists at all.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.