Wow, what a strange request. Can I ask why you need some? Just as a precaution for opioid use? May I suggest naloxone instead if that is the case.
Or is this something for long term alcohol or opioid addiction treatment?
You can often get naloxone from needle exchanges or harm reduction facilities, but you will rarely find naltrexone. Some addiction doctors will prescribe low dose naltrexone PO (by mouth) for addiction, but with the approval of the Vivitrol suspension for opioid dependance most doctors no longer use naltrexone PO.
