BBC article here
It seems to be a chip controlled implant, which releases dose unless told not to. It could last for 16 years, and does not need removing if you want to TTC. And could be available from 2018.
It's said to be tamper-proof (as you need to be extremely close (skin contact?) to communicate with the device, and it's encrypted).
My first reaction is that I wouldn't want communicative chips implanted for any reason. But perhaps this is the way medicine is going. Does anyone else share my revulsion? Or am I being silly?