Red Light Therapy for Peripheral Artery Disease: Scientific Evidence

Among 30 older men with peripheral artery disease (PAD), a 2022 randomized controlled trial tested whether a laser applied to acupuncture points, added to usual drug treatment, could ease the leg pain that comes on with walking. The men, aged 60 to 70, were split evenly into a study group of 15 that received red light at 652.7 to 656.7 nm from a diode laser held against the skin at 9 acupuncture points on the affected leg or legs, delivering 37.35 to 44.65 mW and 2 J/cm² for 60 seconds per point, 2 times per week across 35 days, and a control group of 15 that stayed on drug treatment alone. Only the study group reported meaningfully less walking-related leg pain, with 8 of its 15 men no longer meeting the criteria for the symptom by the end, against 1 of 15 in the control group. Distance walked in 6 minutes rose from an average of 214 to 318 meters in the study group, while the control group showed little change, though the trial found the gap between the 2 groups was not statistically significant on this measure. No unintended effects or harms were reported after the treatment.

Researchers in Brazil compared a laser applied to acupuncture points against traditional needle acupuncture in a 2010 clinical trial of peripheral artery disease. 40 people with poor circulation in the legs were split into 2 groups of 20, with the laser group treated at 10 points using a red diode laser at 650 nm and 50 mW, delivering 2.4 J/cm² in 4-second stimulations across 35 days, and the needle group treated with standard acupuncture needles. 17 of the 20 people in the laser group showed a change in the balance between ankle and arm blood pressure, against 11 of 20 in the needle group, a statistically significant difference. According to the trial, only the laser group showed a meaningful rise in blood pressure in the legs, which pointed to a stronger local effect on circulation rather than a whole-body one.

80 patients aged 50 to 78 took part in a 2002 observational study of low-intensity laser treatment for peripheral artery disease. Each had lived with blocked blood flow in the limbs for about 5 years, and the light was applied at acupuncture points using red light at 630 nm from a helium-neon (HeNe) laser delivering 5 mW/cm² across a 25 mm spot, together with a near-infrared laser at 890 nm running in pulsed mode at 8 W. 88.2% of patients appeared to gain a clear benefit from the treatment, and the remaining 11.8% were recorded as having a satisfactory response.