"nexplanon is definitely effective if you don&#039;t want to have a baby. i&#039;ve had it for 3 years and just got it replaced. while i was on it , my periods were irregular , light and longer but not painful. i had no issues with weight gain or weight loss. my moods were regular. i did notice when my nexplanon was expired , my mood swings were crazy and i uncontrollably ate and gained couple of pounds. now that i&#039;m back on it, my cravings and moods have improved, but my period is way off. like it&#039;s been almost 31 days and haven&#039;t seen any sign."