"I took Yaz for a little over 2 years.  From around the age of 16 to 18.  I gained a little bit of weight, not much but EXTREMELY hard to lose.  Also, I experienced mood swings frequently.  Sometimes getting extremely upset and feeling the need to cry.  But the reason I stopped taking Yaz was because I started to get EXTREMELY BAD migraines/headaches.  These headaches would come VERY frequently.  I would say averaging around 2-5 days a week.  MIgraines run in my family but funny thing is I never experienced them before the pill.  Also, nothing would help these headaches.  I took everything from Tylenol to Excedrin Migraine.  Nothing helped.  Hoped this helped! good luck!"