Potassium azeloyl diglycinate, this ingredient has excellent whitening/lightening benefits, and also helps regulate sebum and moisturize the skin.

Azelaic acid is an awesome ingredient with anti-inflammatory, skin lightening and anti-acne effects, but its insolubility (it's soluble neither in water nor in oil) makes it difficult to use it in a cosmetically elegant and versatile way.

Azelaic acid is very water soluble, easy to use in nice formulas, this is why azelaic comes with essitional frequently. Find out more about formula