Azelaic acid, AHAs and PHAs at higher concentrations appear to diminish hyperpigmentation. In summary, salicylic acid is an aromatic hydroxy acid, and AHAs, PHAs and ABAs are aliphatic. Hydroxyacids. At present, only vitamin A and aliphatic hydroxy acids have been shown to be topically effective for photoaging skin.

Many ingredients combined can make a heavenly skin recipe – others just don’t belong together. Mixing certain active ingredients can compromise the skin barrier and lead you down an uncomfortable path of inflammation, irritation and dehydration. But how do you know what does and doesn’t make the perfect skincare partner? Here we give you the lowdown on the art of skincare match-making.