Unless it is absolute shit dope, $20 worth of Heroin is enough to make someone without a tolerance OD. I've seen more than 1 person OD on one $10 bag IV.
If you are shooting $20 worth of dope a day for more than a couple weeks, you are dependant and addicted.
Trying to use Naltrexone for this purpose is going to end badly. You will probably end up using too much and going into precipitated withdrawals for 3 days, at which point you will not be able to deny you're an addict to anyone or yourself.
Unless this were being administered by medical professionals with exact dosages, I don't see how it could work. I seriously, seriously doubt the ability of ultra low dosages of Naltrexone to do this. I would say it is physically impossible for you to administer this medication to yourself successfully for the purpose you wish to use it for. Meaning, if even if you managed to accurately give yourself less than a milligram of Naltrexone from a 50mg Rx pill, I do not think it will do what you think it will to you.
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