Table 1_The importance of power in photobiomodulation: a systematic review and meta-analysis of high-intensity laser therapy.docx

By contrast, Class IV high-intensity laser therapy (HILT; ≥ 0.5–80 W), typically at ∼100-fold higher power, has proven successful for many of these deeper tissue indications.</p>Methods<p>We systematically searched PubMed, Google Scholar, and the Cochrane Database for Class IV HILT trials published from 2018 to April 2026, classifying interventions as effective when they showed large effect sizes (Cohen’s d > 0.8).</p>Results<p>Across 105 included studies (n = 2,710 HILT; n = 2,925 controls), no serious adverse events were reported.

HILT reduced pain in all randomized trials of knee (k = 27), spine/neuromuscular (k = 20), shoulder/arm (k = 20), and wounds (k = 2), with > 90% showing large effect sizes. Additional benefits were observed in disorders of the feet (k = 13), hand/wrist (k = 8), face/jaw (k = 7), osteoporosis (k = 2), endometriosis, coronary artery disease, cognitive impairment, fibromyalgia, COVID-19, and obesity. HILT yielded durable analgesia, with large VAS pain reductions at end of treatment, < 3-month, and ≥ 3-month follow-ups (SMD -0.98, -1.18, and -1.01; k = 50, 19, and 21, respectively).