An LDN site (The Low Dose Naltrexone Homepage) claims that LDN is effective in treating these conditions:
Bladder Cancer, Breast Cancer, Carcinoid, Colon & Rectal Cancer, Liver Cancer, Glioblastoma, Lung Cancer (Non-Small Cell), Lymphocytic Leukemia (chronic), Lymphoma (Hodgkin’s and Non-Hodgkin’s), Malignant Melanoma, Multiple Myeloma, Neuroblastoma, Ovarian Cancer, Ovarian Cancer, Pancreatic Cancer, Prostate Cancer (untreated), Renal Cell Carcinoma, Throat Cancer, Uterine Cancer,ALS (Lou Gehrig’s Disease), Alzheimer’s Disease, Ankylosing Spondylitis, Autism Spectrum Disorders, Behcet’s Disease, Celiac Disease, Chronic Fatigue Syndrome, CREST syndrome, Crohn’s Disease, Emphysema (COPD), Endometriosis, Fibromyalgia, HIV/AIDS, Irritable Bowel Syndrome (IBS), Multiple Sclerosis (MS), Parkinson’s Disease, Pemphigoid, Primary Lateral Sclerosis (PLS), Psoriasis, Rheumatoid Arthritis, Sarcoidosis, Scleroderma, Stiff Person Syndrome (SPS), Systemic Lupus (SLE), Transverse Myelitis, Ulcerative Colitis and Wegener’s Granulomatosis.

The site offers no independent support for any these claims.

In my view it is up to NT members to judge for themselves how plausible it is that Naltrexone, an opiate receptor antagonist, may be beneficial for such a vast array of health problems.