Naltrexone is an opioid receptor antagonist. It binds to opioid
receptors in cells. The FDA has approved its use for drug
detoxification and chronic treatment of opioid dependence. Dosages
for these purposes range from 50 mg to 150 mg.
LDN is Low Dose Naltrexone. In low doses (4.5 mg), some believe
it will help certain symptoms of Multiple Sclerosis, arthritis, and
other autoimmune diseases, but that has not been verified by
scientific studies (September 2014).