Comparison
GHRP-6 vs. Thymalin
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Growth
Healing
CAS no.
87616-84-0
63958-90-7
Molecular weight
873.02 g/mol
1000 g/mol
Half-life
0.4 h
0.5 h
Sequence
His-D-Trp-Ala-Trp-D-Phe-Lys-NH2no data
Mechanism 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.
Thymalin
Thymalin is a complex of multiple polypeptides extracted from bovine or calf thymus. Postulated mechanisms include modulation of T-lymphocyte maturation, influence on interleukin profiles and stimulation of cellular immune response. Being a multi-component preparation, individual mechanisms are difficult to disentangle. Khavinson and colleagues from St Petersburg have described the mechanism over decades in Russian publications.
Evidence base
Highest evidence
Human trial
Human trial
Studies
4
4
of which in humans
2
2
Effects recorded
4
3
Open conflicts
1
1
Documented adverse events
2
1