3ct KIEHL'S Retinol Skin Renewing Daily Micro Dose Serum 0.34oz 10ml Deluxe Sample size. (0297) Micro‑Dose Formula (0.1% Pure Retinol) from Kiehl’s is encapsulated to ensure a gentler, more stable release of the active ingredient, reducing the risk of irritation. Packaging is airless, which also helps preserve formulation integrity.   • Features skin-supporting ceramides, peptides, and panthenol (pro‑vitamin B5) which hydrate, soothe, and strengthen the skin barrier.