Methods/Design: 65 years old or older persons referring to the Geriatric Unit of the Fondazione IRCSS Ca' Granda Ospedale Maggiore Policlinico of Milan complaining of noncancer chronic pain of any origin will be eligible. Each trial will be a placebo-controlled randomized crossover trial including two um-PEA (600 mg twice a day) and placebo treatment pairs. um-PEA or placebo 3-week periods will be separated by 2-week washout intervals to overcome the possible carryover effect. Pain intensity, need for on-demand analgesic medications, and impact on daily activities will be evaluated. Also, cognitively impaired patients will be eligible as long as the expression of pain can be recognized and its frequency assessed by a caregiver. Trial results will be then discussed with the patient/caregiver and the treating physician to decide whether to continue the treatment. The impact of the N-of-1 approach on the physician's management plan and confidence will be assessed. Investigators will secondarily meta-analyse the performed N-of-1 trials to obtain an estimate of the average effect of um-PEA compared with placebo using a frequentist and Bayesian approach.