Comparison
GHK-Cu vs. GHRP-6
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Cosmetic
Growth
CAS no.
49557-75-7
87616-84-0
Molecular weight
340.4 g/mol
873.02 g/mol
Half-life
no data
0.4 h
Sequence
GHKHis-D-Trp-Ala-Trp-D-Phe-Lys-NH2Mechanism of action
GHK-Cu
Endogenous tripeptide (glycyl-L-histidyl-L-lysine) that chelates copper(II) ions. In skin-cell models and skin biopsies an influence on collagen synthesis, antioxidant markers, gene-expression profiles and wound-healing processes has been described. In topical use in cosmetic studies, changes in various skin parameters have been reported.
GHRP-6
GHRP-6 is a high-affinity agonist of the growth-hormone secretagogue receptor 1a (GHSR-1a) — the same receptor later shown to bind the endogenous hormone ghrelin. The identification of GHRP-6 as a pharmacological anchor led to cloning of GHSR in 1996 and the discovery of ghrelin itself in 1999. GHRP-6 stimulates pituitary GH secretion via a pathway independent of GHRH and can be combined synergistically with GHRH. Via GHSR in the hypothalamus it additionally activates NPY/AgRP neurons, producing an orexigenic (appetite-stimulating) effect in animal models.
Evidence base
Highest evidence
Human trial
Human trial
Studies
3
4
of which in humans
1
2
Effects recorded
4
4
Open conflicts
1
1
Documented adverse events
2
2