Etonogestrel
"I have been on for almost six years I've had it replaced once. This up coming October I'll probably have it replaced again.  For me the first one my periods were random.  No period for 3 months then spotting for one month.  After having it replaced the second time it's been less period all around light spotting.  Again considering it again in October just wanted to see the effects others have had.  No weight gain or acne for me. I have a slight temper already so wouldn't have noticed mood swings"