One in five Canadians live with chronic pain, defined as pain that lasts longer than 3-months.Living with chronic pain has a detrimental impact on physical health, emotional health, and quality of life. Current treatments rarely result in pain relief and often do not meaningfully improve physical or emotional function. Further, medication used to treat pain often causes unwanted symptoms. There is a need to develop new treatments to help manage chronic pain. The use of a nasal spray containing manufactured oxytocin may improve pain management. Oxytocin is produced in the human body and has been shown to impact the pain pathway in animals. Our project tests whether the use of a nasal spray containing oxytocin will improve pain and function in men and women who live with chronic pain. Men and women with chronic nerve, muscle, or pelvic pain will be recruited in Vancouver, Calgary, and St. John's. Each person will be assigned to complete three interventions in a random order. Each intervention involves using a nasal spray twice per day over a 2-week period. The nasal spray will contain a small dose of oxytocin during one intervention and a medium dose during the second intervention. The nasal spray during the final intervention will have no oxytocin. This final intervention is a control intervention that will allow us to measure the effect of simply taking a nasal spray (i.e., the impact of expectation). Participants and researchers will not know which interventions involve the use of oxytocin. Participants will rate their pain and function each day throughout each task. We will calculate each person's score on pain and function. We will test whether participants report less pain and better function when they use oxytocin compared to the control. The results of this project may improve pain,function, and quality of life among those who live with chronic pain.