Beauty Clinic: Dr Rabia Malik on AHAs/BHAs and exfoliators
Q. Could you explain how AHAs and BHAs work as opposed to an exfoliator/facial scrub? Should I use an AHA or BHA? And should I combine it with a facial scrub? I am 58 with combination skin and have started getting the odd spot around my chin area.
A. We asked Dr. Rabia Malik, a GP and private holistic aesthetic doctor, for her advice. She says: ‘AHAs and BHAs are different types of acids that, depending on their concentration and pH [acid balance], provide varying degrees of exfoliation. So a product containing an AHA such as glycolic acid or a BHA such as salicylic acid is a form of chemical exfoliator. As such, it should not be used at the same time as a physical, granular exfoliator or you risk stripping the skin and damaging the protective acid mantle.’
Dr. Malik (drrabiamalik.com) adds that if you want to use both a chemical and physical exfoliator, they could be used on different days. ‘For most skin types, however, using each type of product once a week is normally sufficient.’
Depending on the formulation, AHAs and BHAs may be left on the skin or they may need to be washed off. Physical exfoliators always need to be rinsed away.
For your type of skin, Dr. Malik has found that an AHA such as mandelic acid is helpful. She recommends The Ordinary Mandelic Acid 10%/£5.80 for 30ml, which works well alongside a cleanser or face wash containing salicylic acid such as Cosmedix Purity Clean/£42 for 100ml, which she now stocks on her website.
Dr. Malik suggests you use a salicylic acid face mask one or twice a week, e.g. The Ordinary Salicylic Acid 2% Masque/£9.90 for 50ml.
There is a confusing number of different acids now used in skincare. AHA stands for alpha hydroxy acid and BHA for beta hydroxy/salicylic acid. Both types work to gently unglue the bonds holding dull dead skin on the surface so the cells are shed invisibly.
When you hear about ‘fruit acids’ it usually means AHAs such as citric acid found, for instance, in lemons and strawberries, or malic acid from apples and mangoes.
There’s a helpful breakdown of the difference between AHA and BHA exfoliants on Paulaschoice.com. Basically AHAs are water-soluble so only work on the surface of the skin. They help hydrate normal to dry skin and are effective in reducing visible signs of sun damage. BHA is oil soluble and works both on the surface of the skin and deeper inside the pores. It’s naturally skin calming and said to be gentle enough for sensitive skin or if skin is prone to redness.
