It's a serum! It's a foundation! It's ... both? Trinny London's newest product is the Trinny London BFF De-Stress Tinted Serum (£39), and in addition to being a light coverage base product (it does a bang up job of covering redness), it's also a serum full of active ingredients. It contains a load of antioxidants, as well as a proprietary ingredient complex that features a high percentage of Neurophroline, a synthetic active ingredient that helps block the production of cortisol, the hormone your adrenal glands release when you're stressed that has damaging effects on your body, including making your skin look tired, dull, and lacklustre. We just wish the brand launched with more than just 12 shades, as there aren't as many options for people with dark, deep skin tones.