What is a toner and do I need one?

A toner is a liquid applied after cleansing to balance skin pH, provide lightweight hydration, or deliver active ingredients. Modern hydrating toners — especially Korean beauty essences — deliver a meaningful dose of humectants and skin-soothing ingredients. Astringent toners with alcohol are largely outdated and can damage the barrier. Whether you need one depends on your skin goals: they are helpful but not essential if your serum and moisturizer meet your needs.