Diabetic foot ulcers (DFU) are among the late complications of DFU, defined as skin lesions that involve the dermis to deeper structures, such as muscles and bones. Although preclinical studies have demonstrated the effects of GaAs 830 nm in diabetic wounds, no clinical studies have been performed, revealing the need for more in-depth analyses to identify the effects and ideal parameterization of PBM with GaAs 830 nm wavelength in the treatment of diabetic ulcers, improving quality of life, as well as to understand the therapeutic feasibility, time required for healing and recurrence rates of these lesions. Experimental, randomized, controlled, double-blind study, with blinding applied to the evaluator and participants. A total of 136 volunteers will be recruited for the research, carried out at the Integrated Center of Medical Specialties (CIEM) - Polyclinic. LLLT GaAs 830nm will be used with three dosages of low, medium and high intensity (4 J/cm², 8 J/cm², 12 J/cm²). The study will have three intervention groups using LLLT with GaAs 830nm and a control group, in which LLLLT will be performed with a GaAs 904nm wavelength and a dose of 10 J/cm², according to Saura et al (2024). This study was approved by the local Research Ethics Committee (Opinion 7,488,044), conducted in accordance with the Declaration of Helsinki and in accordance with the CONSORT (Consolidated Standards of Reporting Trials) guidelines.

Inclusion Criteria:

• Volunteers of both sexes
• Age over 18 years
• Medical diagnosis of diabetes mellitus (DM)
• Presence of diabetic ulcer

Exclusion Criteria:

• Autoimmune diseases
• Infected diabetic ulcers
• Osteomyelitis
• Ischemia
• Concomitant psychiatric disorders
• Contraindications to treatment methods