Ingredients and actives

Alpha arbutin

Also written as arbutin serum, brightening serum.

A brightening active that darkens on exposure to light and heat, which is a problem for a product sold on evening skin tone.

What it needs from a bottle

Amber or opaque. An arbutin serum that browns in the bottle undercuts the claim on the label, and customers photograph that sort of thing.

Formats that suit it

• Amber glass droppers
• Airless pumps