Refresh your skincare routine with COSRX The Retinol 0.5 Oil 20ml — a concentrated night treatment designed to help improve the look of fine lines, uneven texture, and loss of firmness while keeping skin feeling nourished. COSRX’s official product page describes it as a 0.5% pure retinol oil in a nourishing base, and highlights squalane and vitamin E as key supporting ingredients.