Naltrexone HCl is primarily used in the treatment of alcohol and opioid dependence. It works by blocking the effects of opioids and reducing the craving for alcohol, helping individuals maintain sobriety. In the medical field, it is often prescribed as part of a comprehensive treatment plan that includes counseling and behavioral therapy. Additionally, low-dose naltrexone (LDN) has gained attention for its potential use in managing chronic pain conditions, autoimmune diseases, and certain inflammatory disorders. It is also being explored for its role in treating conditions like fibromyalgia and multiple sclerosis, where it may help modulate the immune system and reduce symptoms.