New — Free Peptide Starter Guide (2026): 13 chapters, 34 cited studies

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ToolsCompareAHK-Cu vs Dihexa

AHK-Cu vs Dihexa

Side-by-side comparison of key properties, dosing, and research.

Skin & CosmeticAnti-Aging & Longevity
AHK-Cu
Cognitive Enhancement
Dihexa
Summary
AHK-Cu is a copper tripeptide composed of alanine, histidine, and lysine chelated to copper. Distinct from GHK-Cu, AHK-Cu exhibits strong affinity for hair follicle receptors and demonstrates potent hair growth stimulation alongside wound healing and skin regeneration properties.
Dihexa is a potent experimental oligopeptide derived from angiotensin IV that dramatically enhances synaptogenesis. Preclinical research shows cognitive enhancement orders of magnitude more potent than BDNF — it is considered one of the most powerful nootropic compounds in research, but has very limited human safety data.
Half-Life
Hours (topical, variable by formulation)
Unknown (limited pharmacokinetic data)
Admin Route
Topical, Scalp application, Subcutaneous (research)
Oral, SubQ, Topical
Research
Typical Dose
0.01–0.1% concentration
5–10 mg
Frequency
Once or twice daily
Daily
Key Benefits
  • Stimulates hair follicle growth and reduces shedding
  • Increases dermal papilla cell proliferation
  • Promotes wound healing and skin regeneration
  • Antioxidant protection via superoxide dismutase activation
  • Improves skin elasticity and firmness
  • Supports collagen and elastin production
  • Dramatically increases synapse formation (potentially 10 million× more potent than BDNF in animal models)
  • Enhances memory and learning
  • May reverse cognitive decline
  • Improves neuroplasticity and executive function
  • Long-lasting cognitive benefits from short courses
  • Potential therapeutic agent for Alzheimer's
Side Effects
  • Generally well-tolerated topically
  • Mild scalp irritation or redness in sensitive individuals
  • Possible temporary hair shedding phase at treatment initiation
  • Copper accumulation with excessive systemic use (rare)
  • Headache
  • Irritability
  • Brain fog during washout period
  • Unknown long-term effects (insufficient data)
Stacks With