Naltrexone is a medication that is used conventionally in the treatment of opiate addiction. In low dose naltrexone therapy (LDN), though, it is used to treat a wide range of autoimmune diseases and is commonly used in cancer therapy as well. LDN is an immune modulator and so is indicated in any conditions characterized by an imbalanced immune response. The physiological effect of LDN is to increase the production of endorphins, which are the body's natural "feel good" molecules. In this way, LDN can also have a positive impact on depression and general wellbeing.