GHK Cu 200MG (Topical) Raw Amino Copper Peptides vs. Retinol: Which Anti Aging Powerhouse is Right for Pure & Cimple Alternating tretinoin and GHK Cu (copper peptides) nightly maximizes anti aging benefits while minimizing irritation. , Both are potent but DIFFERENT actives. Tretinoin speeds up cell turnover and Peptides vs. Retinol Which is Better For Skin Health? There is no definitive answer as to whether retinol vs peptides are better for anti aging. However, there is a lot more research backing retinol as an effective ingredient, while peptides are still The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline