It is not intuitive to think that something as seemingly inconsequential as pH could have a mighty impact on ageing but it does. As we age, the pH of our skin drifts from around 4,5 in our prime to a little over 5 by the time we reach old age. In the world of microbes, small changes in pH determine which kinds of bacteria dominate in an ecosystem. For skin, that means that small shifts in the wrong direction can lead to imbalances that see opportunistic microbes start to dominate – think acne, eczema, rosacea and sensitivity.

That might sound overly technical but you can commission your skincare products to manage your skin’s pH without having to give it much thought. Just make certain that ALL the products in your chosen range are pH balanced at around 4,5. Many ranges balance their cleansers, but keeping emulsions stable at low pH isn’t always easy, so moisturisers are often pegged at around pH 7.

Once in the right place, your microbiome helps you to self-regulate by producing acids (such as lactic acid) that keep things healthily acidic. You can help your probiotic partners out by ensuring never to disrupt the pH on your skin. A disrupted acid mantle takes up to 18 hours to re-balance, this is generally longer than the time between cleansing and product application, so if your products are not pH balanced, your microbiome will be totally pre-occupied with trying to set the pH straight and not get around to performing all its other valuable functions.