More concentrated than a cream, a serum is applied after toner to target a specific concern. Hydration: Evolve Beauty's Hyaluronic Serum 200, Torriden's Sérum à l'Acide Hyaluronique. Radiance and dark spots: Westman Atelier's Suprême C Serum, KORA Organics' Kakadu Plum Vitamin C Serum, RANAVAT's Brightening Saffron Serum. Lines and firmness: Agent Nateur's Holi (Lift) Ageless Lifting & Firming Serum, MERME Berlin's New by Morning Retinal Face Serum. Blemishes: Evolve Beauty's Salicylic Rescue Blemish Serum.