In the last few years [Smith] has seen formulations change less to improve the delivery and active ingredients and more to address various marketing concerns.

The first change came with the removal of mineral oil, which was in the vast majority of skincare, because it clogged the pores.

Then came the addition of silicones and high molecular weight silicone elastomers that give serums their silky feel, but are a purely cosmetic ingredient that washes off. ‘It completely changed the market,’ Smith adds, ‘because this silky feel without being oily or greasy was really desirable.

(c) the science of skincare