Fluoxetine is a widespread antidepressant medication, with side effects, including xerostomia. In search of treatments to reduce discomfort, PBM is one of the alternatives that has proven to be effective. This article aims to demonstrate the clinical evolution of a female patient, L.R.O., 55 years old, who reported severe oral discomfort due to lack of saliva. The selected treatment was the Low Power Laser - EccoFibras with vascular photobiomodulation, in radial artery for 30 minutes, wavelength 660nm and power of 100mW, with 180J energy delivery. After the first treatment session, the patient reported improvement and satisfaction and, due to the unpredictability of psychiatric discharge, she tried to perform weekly applications. With each session, she reported a decrease in symptoms, which encouraged her attendance. With the prevention of xerostomia, the pacient achieved a clear increase in her quality of life, demonstrating that vascular photobiomodulation can be an interesting low-cost non-invasive treatment.