Etonogestrel
"There seems to be a lot more negative reviews on this than positive, but I can't recommend the Nexplanon enough! I was recommended this as I get extremely nauseous with most birth control pills, and haven't experienced any since getting it.  I got the implant in Oct 2014, and have had only one period since. I have gotten occasional spotting, but it's been extremely minimal (literally like a spot), and it's only been a total of three days out of nine months. I've actually lost weight and my skin has cleared up as well. I do have a suspicion that this has made me more susceptible to headaches, but they are very infrequent and manageable. I didn't think birth control would ever be this hassle free and effective!"