We all have a small amount of Azelaic acid in our systems that mainly comes from our dietary intake. Azelaic acid can also be metabolized in our bodies from Oleic acid. The actual concentration of Azelaic acid in each individual varies considerably depending on what kind of diet we have.
A side effect when using azelaic acid for acne is hypertrichosis (stimulation of hair growth). After noting this side effect some people have tried to use Azelaic acid to treat hair loss diseases such as androgenetic alopecia, telogen effluvium, and alopecia areata. No controlled studies have been conducted to see how effective it is or how it might work to permit/promote hair growth in people with these conditions. It apparently has a good hair growth stimulating effect for some people.