The implant is a specially compounded, implantable formulation of naltrexone that is made specifically for each individual program patient participant only after a prescription is written by medical caregiver who deems that the individual patient is a good candidate for the implant formulation. Compounding is a common and legal process used by licensed pharmacies to create special formulation and/or combinations of FDA approved drugs by prescription. The pharmacies that make each implant must strictly follow state and federal compounding laws. Naltrexone implants have been used successfully and safely worldwide for approximately 20 years. Tens of thousands of individuals worldwide have successfully undergone treatment for addiction with the use of naltrexone implants.