A very hydrating and nourishing serum:

Hyaluronic Acid: When applied to the skin, it "attracts and holds water leading to a plumping and hydrating effect," making your skin look healthier.

Niacinamide or Vitamin B3: Helps improve uneven skin tone, softens fine lines, diminishes dullness, and reduces pore size over time.

D-Panthenol (Vitamin B5): Improves the texture of the skin and makes it softer and smoother. It has moisturizing, soothing, and anti-inflammatory properties.