Background: Chronic pain in the elderly is highly prevalent, often underestimated, and associated with adverse outcomes. Most available analgesic drugs are often either ineffective or not tolerated, and burdened with many side effects. Palmitoylethanolamide (PEA) is an endogenous widely distributed N-acylethanolamina involved in neuroinflammation and pain generating processes. Formulations containing ultra-micronized Palmitoylethanolamide (um-PEA) are available on the market but their effectiveness on chronic pain in highly heterogeneous geriatric patients is not clear and likely not generalizable. Investigators planned to adopt the N-of-1 trial approach to objectively test the effectiveness of ultra-micronized PEA at an individual level in our older outpatients.