Apply a pea‑sized amount to clean, dry skin on the face and neck in the evening, avoiding the eye contour area. If you are new to retinol, start by using the serum 2–3 times per week, gradually building up to nightly application as your skin builds tolerance. A slight tingling or mild flaking may occur initially. Always apply a broad‑spectrum sunscreen during the day, as retinol increases photosensitivity. Patch testing prior to first use is recommended.