Biological chemistry
The honest boundary is that even the coherent pairing is a mechanistic hypothesis with no human validation, so the most defensible research posture is to study the single compound at its documented dose first, and treat any combination as a further, clearly-labelled research question rather than a default
Changes in caveolin-1 may release eNOS and allow more nitric oxide-related activity
Drugs that reduce hepatic blood flow (e.g., propranolol, a -blocker) can decrease their own clearance
Stimulation of matrix synthesis In fibroblast cultures, GHK-Cu increases the synthesis of the major structural molecules of the extracellular matrix: collagen, elastin, and the glycosaminoglycan/proteoglycan ground substance (including dermatan sulfate and other glycosaminoglycans)
The tumour suppressor protein VHL targets hypoxia-inducible factors for oxygen-dependent proteolysis