Truncation studies showed that the membrane proximal 61 amino acids of GP130 are sufficient for signal transduction (68), and later it was shown for GHR that the membrane proximal 20 residues (which includes the Box1 motif) of the ICD is sufficient for JAK2 binding, but not sufficient for GH-induced activation of JAK2 (69)
doi:10.3390/ijms19071987 Wang X, Liu B, Xu Q, et al
For the broader population of healthy adult researchers, GHK-Cus side effect profile makes it one of the more forgiving compounds in the regenerative peptide category
The community protocol steps down by phase: 10 units on an insulin syringe (4 mg total blend: 2.5 mg GHK-Cu, 500 mcg KPV, 500 mcg BPC-157, 500 mcg TB-500) 5x/week during loading, then 5 units (2 mg total blend) 3x/week for maintenance
Valgimigli, Luca
The skin barrier is not ready