What it is
Azelaic Acid is derived from grains such as wheat, barley and rye. Its trade name is Azalex.
What it does
When applied topically in concentrations between 15% to 20%, Azelaic Acid is effective at treating several skin conditions.
Because of its antibacterial properties, it is used to treat mild to moderate acne: it works by reducing the growth of Propionibacterium acnes and Staphylococcus epidermidis bacteria which help cause acne and by keeping pores clean.
It is also used to reduce skin discoloration and is a good alternative to hydroquinone, particularly for dark-skinned people with melasma or dark spots left by acne. Hydroquinone has, in fact, been linked to Ochronosis, a condition that darkens the skin which affects mostly black people but can occur in Caucasians and Hispanics too.
In addition, Azelaic Acid can also diminish inflammation and is effective at treating rosacea.
High concentrations of Azelaic Acid can be irritating. Because of that, products that contain a big amount of the ingredient (about 20%) are only available by prescription.