TNF and rheumatoid arthritis: Finally, a controlled before-after study grounded on the Norwegian Prescription Database (NorPD) compared prescriptions to RA patients one year prior to and one year after starting LDN and found a reduction in the use of NSAID, opioids, and DMARDs such as methotrexate and anti TNF-alpha drugs.19 Additionally to its analgesic and anti-inflammatory properties, LDN may work as an immunomodulating agent by directly binding on the opioid growth factor receptor (OGFr) within immune and tumour cells.26