Of every skincare product category, sunscreen has the strongest and most consistent evidence behind it for preventing visible skin aging and reducing skin cancer risk.
UV exposure is the dominant external cause of premature skin aging — wrinkles, uneven tone, and loss of elasticity attributed to “aging” are very often substantially UV-driven rather than purely chronological.
This is why dermatologists consistently rank daily sunscreen above serums, retinoids, or any other single product when asked what matters most. A sophisticated routine with excellent actives but no daily sunscreen is working against a far larger counteracting force.
Daily use, including on cloudy days and through windows, matters more than chasing a marginally higher SPF number — consistency outperforms a high SPF number used inconsistently.