Both are popular for supporting firmer, smoother-looking skin, but they work in different ways.
Retinol accelerates cell turnover, which can deliver faster visible results but often comes with a trade-off: dryness, sensitivity, and sun sensitivity, especially when you're first starting out.
Copper peptides take a gentler approach. Rather than forcing rapid turnover, they support your skin's own collagen production and repair processes over time. That means results build more gradually, but with far less risk of irritation — making it a strong option for people with sensitive skin, or anyone who wants a lower-maintenance addition to their routine.
Many people actually use both: retinol in the evening, copper peptide serum layered in the morning (or on alternating days) to get the benefits of each without overwhelming their skin barrier. If you're new to actives altogether, starting with a copper peptide serum is often the more comfortable entry point.