naltrexon 3 mg how long is 50mg of naltrexone effective About Essence-In-Use › Forums › Essence-In-Use › naltrexon 3 mg how long is 50mg of naltrexone effective This topic has 0 replies, 1 voice, and was last updated 2 years, 3 months ago by SofiaDameron. You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In