A drug that is simultaneously affordable, devoid of severe side effects, and applicable to a wide range of diseases is not often found in the modern pharmaceutical landscape. But as medical professionals and researchers alike continue to discover, Low Dose Naltrexone (LDN) boasts this remarkable combination. LDN, originally prescribed in higher doses as a treatment for opioid addiction, works by blocking opioid receptors, thereby stimulating the production of endorphins, mitigating the inflammatory process, and stabilizing the immune response. Prescribed off-label and administered in small daily doses, this generic drug has proven useful in treating many different ailments. Expanding on the information presented in The LDN Book Volume 1—which showcased LDN’s efficacy in treating conditions such as lupus, thyroiditis, autism spectrum disorder, and chronic fatigue—Volume 2 highlights the latest clinical trials, case studies, and research on LDN. More than a dozen medical professionals explain how they are using LDN to help patients suffering from chronic pain, Parkinson’s disease, dermatologic conditions, traumatic brain injury, Lyme disease, and more. The LDN Book Volume 2 is both a resource for practitioners, pharmacists, and patients, and a renewed call for further research on a little-known drug with big potential.