GHK vs Thymulin

Cosmetic

Immune

Research Only

Research Only

GHK is a high-affinity ligand for copper(II), forming the GHK-Cu complex that mediates most of its documented biology. Via the copper-bound form, GHK is proposed to modulate expression of a large number of human genes (microarray and Broad Institute Connectivity Map analyses from Pickart's group), including pathways related to extracellular matrix remodeling, antioxidant response element induction, angiogenesis, and DNA repair. Reported in vitro and preclinical effects include stimulation of fibroblast collagen and glycosaminoglycan synthesis and acceleration of wound healing. The bare (non-copper) peptide is typically weaker than GHK-Cu in these assays and is generally assumed to acquire copper in serum-containing environments.

Thymulin binds one zinc ion in a 1:1 stoichiometric complex that is required for biological activity. The zinc-thymulin complex engages high-affinity receptors on T-cell precursors and modulates T-cell differentiation and cytokine production in preclinical systems. Zinc deficiency effectively abolishes measurable thymulin activity regardless of peptide concentration. Thymulin-related peptides have shown analgesic and anti-inflammatory effects in rodent pain models, possibly involving opioid-sensitive central pathways.

50–200 ppm topical (~0.005–0.02%)

100–500 mcg (research-only, not clinically validated)