Ingredients and actives

Vitamin C

Also written as L-ascorbic acid, ascorbic acid serum, vitamin C serum.

Pure L-ascorbic acid oxidises in water and turns orange, then brown. Derivatives are more stable and less potent, which is the trade every vitamin C formulator makes.

What it needs from a bottle

Nothing punishes bad packaging faster. An oxidising vitamin C changes colour in the bottle, so the customer watches your product spoil through the glass. Amber or opaque, and airless if the budget stretches. If you are set on a clear bottle, use a derivative and say so on the label.

Formats that suit it

• Amber glass droppers
• Airless pump bottles