How quickly you recover depends on how serious your shoulder injury is. Separated shoulders may heal over a period of 6 weeks. Dislocated shoulders may take longer -- more like 3 to 12 weeks. But these lengths of time are just approximations. Everyone heals at a different rate.1  1. 2  2. 3  3.he same treatment would also be used for a separated shoulder. To treat either injury, you should: 1  Ice your shoulder to reduce pain and swelling. 2  Do it for 20-30 minutes every three to four hours, for 2 to 3 days or longer.