When muscle rather than bone is the cause, injections do narrow the width.
Medication in the muscles around the cheekbones relaxes them, which narrows a face that looked wide at the sides. It lowers muscle tension rather than reducing the cheekbone itself, so the change is small when bone is the cause. Consultation first separates bone from muscle.
One session lasts three to four months. When muscle tension is the cause, the tension eases and the width of the face visibly reduces. If the cheekbone itself is large, however, the change is small regardless of how long it lasts, so sorting out the cause at the consultation is what decides the result.