Comparison
GHRP-6 vs. Bremelanotide
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Growth
Research other
CAS no.
87616-84-0
189691-06-3
Molecular weight
873.02 g/mol
1025.18 g/mol
Half-life
0.4 h
2.7 h
Sequence
His-D-Trp-Ala-Trp-D-Phe-Lys-NH2Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-OHMechanism of action
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.
Bremelanotide
Bremelanotide is a cyclic peptide that binds non-selectively to melanocortin receptors (MC1R through MC5R) — with highest affinity at MC4R in the central nervous system. The precise role of MC4R activation in sexual behaviour is not fully understood; animal data show effects on hypothalamic circuits. Peripheral effects (blood pressure, hyperpigmentation) are attributed to MC1R/MC2R.
Evidence base
Highest evidence
Human trial
Human RCT
Studies
4
5
of which in humans
2
5
Effects recorded
4
3
Open conflicts
1
0
Documented adverse events
2
2