Using Azelaic Acid and Zinc PCA in Separate Formulas

Yes, you can use products containing Azelaic Acid and Zinc PCA together if they are in separate formulas, such as a toner with one and a serum with the other.

The caution against using them in the same formula applies specifically to water-based products (like toners, essences, or gels) that do not have a suspension system. In such cases, combining them in the same product can lead to precipitation or separation.

However, when applied in different steps using separate products, Azelaic Acid and Zinc PCA can be used together without issues.