Levonorgestrel
"I have been using the Jadelle implants ( levonorgestrel, unavailable in the US & UK) for 3 months now. 
My experience has been a rather smooth one, other than irregular menstrual bleeding and feeling nauseous through out the day. 
Plus they are very effective in preventing pregnancy. 

This drug has had no effect on my weight whatsoever. In any case, I have lost almost 20 pounds through exercise and improved diet since I began using it. 

I'd recommend this drug to anyone :)"