Autoimmune diseases are affected by complex pathophysiology involving several cell types, cytokines, antibodies, and mimicking factors. Different drugs are used to ameliorate these autoimmune reactions, including nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, antiantibodies, and small molecular drugs (DMARDs), and they are clinically in vogue for diseases such as rheumatoid arthritis (RA). Nevertheless, low cost-effectiveness, reduced efficacy, adverse effects, and patient nonresponse are unappealing factors driving the development of new drugs such as iguratimod. Iguratimod is primarily used to ameliorate RA in Japanese and Chinese clinics. However, its efficacy against other autoimmune ailments is also under intense investigation, and the number of investigations is becoming increasingly larger with each passing day. The articular structure comprises synovium, ligaments, and bone. The latter is more complex than the others since it regulates blood cells and autoimmunity in addition to providing skeletal support to the body. Therefore, its protection is also of prime importance in RA and other autoimmune diseases. Herein, we have highlighted the role of iguratimod in autoimmune diseases and bone protection. We suggest that iguratimod's unique mode of action compared with that of other DMARDs and its good patient response makes it a suitable antirheumatic and bone-protecting drug.Bone Research (2019) 7:27 ; https://doi.Fig. 2 Effects of iguratimod and other DMARDs on collagen-induced arthritis. a Arthritis score in different DMARD-treated groups. b Arthritis incidence of different treated groups. c The extent of paw edema in various groups. d The body weight measured in various groups after DMARD treatment. e X-ray radiographs of various groups treated with different DMARDs. Arrows indicate the bone erosion area, whereas * and ** indicate significance P-values of <0.05 and 0.01 (*P < 0.05, **P < 0.01), respectively. Adapted from Ref. 21