Depending on how bad it is, yes, it should repair.
The most important things you can do are make sure the stressor is removed (nipping tankmate gone), and make sure you keep up on water changes so that the water is pristine. Bettafix can help, but clean water is the single most important thing you can do to encourage healing.
joy to the fishes in the deep blue sea
55, 30, 30, 20, 10, and 10-gal. freshwater tropical tanks