The Outset Firming Vegan Collagen Prep Serum
This is a firming serum that includes vegan collagen to plump and hydrate the skin. It's designed to be used both morning and night and prepares the skin for your moisturiser – and it's Johansson's favourite product. "My skin is completely addicted to our serum," she says. "My face doesn't look the same when I don't use it!"