Serums are misunderstood.
They are made out to be high-performance products, must-haves for anyone serious about skin care. However, they're not always potent nor necessary.
Let's start with breaking down common misconceptions about serums.
Serums contain the highest amounts of actives
Contrary to popular belief, serums do not always have highest concentrations of actives compared to other types of skin care products. There are no formulary requirements for serums to be high in actives, so just because something is labelled as a serum does not make it more effective than other types of product.
Serums penetrate deeply into skin
Serums are typically light-textured, hence they sink into skin much faster than a thicker product (e.g a moisturiser). Quick absorption does not mean deep penetration. Think about prescription-grade retinoic acid and steroid creams. They don't exist in serum form, yet they are absolutely potent.
The degree of product penetration is rather complicated, involving multiple factors like ingredients’ polarity (electrical charge), molecular size and degree of occlusivity, which can be optimised in any product type, not just serums.
Defining characteristics of serums
So if neither high potency nor penetrability are characteristics exclusive to serums, then what are?
Truth is, serums do not have definitive set of formulary or functional qualities, with the exception of having rather fluid textures. This is because serums are meant to be worn under moisturisers as they do not typically provide enough moisturisation alone.
Do I even need a serum?
That depends! If your basic regime already contains the necessary ingredients to address all your skin concerns, you don't need it. Otherwise, you might want to add an appropriate one to your regime.
Those prone to blemishes or sensitivity will do much better with one product that ticks all the boxes (i.e. treats and moisturises), instead of layering multiple products consistently day and night. The more products we use, the more we subject skin to congestion and irritation.
You don't need a serum for results. It is a term that reflects product category, not efficacy!