The advice for choosing sensitive skin products is usually about what to avoid, like fragrance, or include, such as soothing actives. But this tick-list approach ignores one of the most important parts of a formulation - the base.
This base is the main bulk of your moisturiser or serum. In a moisturiser for example, emulsifiers and thickeners are blended with oil and water-soluble ingredients to create anything from a rich cream to a fine lotion.
The base as an active
We often think of actives as things like vitamin C or peptides, with the rest of the product a neutral, inert vehicle. But this vehicle - the base - interacts with your skin too.
This can be good - like when particular emulsion systems create a barrier-like structure to help keep in hydration. And sometimes it's actually this base, rather than the actives, that makes the difference in a well-loved skincare product.
But the base can also be potentially disruptive. If it disturbs the cell's protective lipids or enables things to get deeper in the skin than is ideal, over time, this can create irritation.
This may not be a big deal if your skin barrier is resilient. But if you already have a barrier which is a little shaky, it's important the base is formulated to be non-irritating, so it doesn't cause further issues.
The formulation challenge
Creating a good cosmetic base is tricky. The chemist has a long list of competing needs to balance, from skin feel, compatibility with tricky 'hero' actives, efficacy and last but not least, stability.
Mildness is not a default. It has to be engineered into formulations. And the truth is, it isn't always top of that long list. This might be ok if your skin is resilient. However if you're someone who find your skincare products regularly sting or trigger irritation, it might be the base that's the culprit.
When it comes to skincare for people with less resilient skin, mildness needs to take priority. It does when we're creating formulations, and it's why our moisturisers are less likely to sting when you apply them, and our cleanser is so incredibly gentle.
So don't just think about what's in or not in the products you're using - the right base might actually be more important.