In that case, I guess my opinion is that Spironolactone has much more scientific evidence to support his effectiveness than azelaic acid, which seems to have none whatsoever, just in vitro studies; there's no in vivo evidence for azelaic acid as far as male pattern baldness is concerned.
If I were to choose between one and the other I'd certainly choose spironolactone. And that's what I'm doing, because I have azelaic acid and zinc and I'm just going to throw them to the trash as I begin again to use spironolactone. I'm not going to waste anymore time again with azelaic acid, as I did in the past, when I would use it twice daily, which probably only served the purpose of screwing my spironolactone applications, 'cause I'd apply the spironolactone solution and immediately after the azelaic acid solution, which probably washed some spironolactone off my scalp (bad idea).