I think you would be talking about the naltrexone implant, an implant only available (as far as i know) in Perth, Western Australia. The treatment clinic that I know of provides this service is Dr. George O'Neil's "Fresh Start" Recovery Program, it is located in Subiaco 5 minutes from Perth.
I myself have received naltrexone implants a couple of times (they don't last for ever) for severe drinking problems I had and they dramatically helped me with that aspect of my addiction
. Now I have my drinking under control and basically the implants completely stop your brain receiving the reward feeling you get from drinking which makes the experience less enjoyable (even the taste isn't the same anymore) and this eventually decreases your desire to drink excessively, if not at all.
The naltrexone implant is mainly used for addiction to opiates
though and has helped many people with all sorts of opioid
addictions all across Australia and some people from other places in the world. The implant works on opioid addiction by basically blocking the opioid receptors in the brain. I know of many people who state that Dr. George O'Neil's naltrexone implant has given them control of there life back, brought there lives to a level of sobriety that they and their family's never thought possible and also people that credit him with saving there lives.
More information can be found by doing a search for "fresh start" in any major search engine. I strongly support the fresh start recovery program and believe that the Australian government should provide more support to Dr. O'Neil and his program instead of wasting so many of their resources arresting anyone who engages in drug
related activity. The drug trade will never be stopped and governments world wide need to accept this fact and focus on education, abuse prevention and harm reduction
. I hope someone out there found this post helpful in some way and encourage people who need help with their addiction to consider this service if possible for them.