As you might remember from science class, pH is the measurement of acidity. But what does that mean in the context of your skin?
Surging hormones
Your skin needs a certain amount of oil to stay waterproof and resist infections. Too little can lead to dry skin and the premature development of wrinkles; too much can lead to oily skin and acne.
The oil in your skin is called sebum and it’s produced by the sebaceous glands, tiny ducts that lie next to the hair follicles.
If you’re a teenager, the hormones that are surging around your system and helping you mature sexually can lead to an interest in pictures of Brad Pitt, as well as an oily skin, which in turn leads to acne. Acne normally passes by the end of the teen years.
How pH is measured
pH is measured from one upwards, with one being highly acidic and 14 eight being highly alkaline. A pH of 7 is neutral. A pH between 1 and 6,9 is acidic and between 7,1 and 14 is alkaline.
Your stomach acid has a pH of one or two, which is why indigestion hurts so much – it’s the acid burning your stomach lining.
Your skin is fairly acidic, which helps it ward off the advances of harmful bacteria and fungi. The optimal pH of human skin is 5,5 and you can measure it with a piece of litmus paper.
Your sweat combines with the sebum on your skin to form something called an acid mantle, which has a pH of 4 to 5.5. Using astringent soap removes the acid mantle and can leave the skin vulnerable to fungal or bacterial infections.
Broadly speaking, be wary of any soap that isn’t labelled "pH balanced”. Body soaps such as Dove, Lux, Palmolive, Breeze and Lifebuoy shouldn’t be used on your face. Any soap that doesn’t carry the words facial cleaning soap on the packaging is unlikely to be suitable for your face.
Try the Gallia’s Gentle Cleansing Bar or the facial cleansing bars by Neutrogena, Clean and Clear, Yardley or Seba Med.