Red Light Therapy for High Blood Pressure (Hypertension): Scientific Evidence

185 patients with borderline high blood pressure, also known as hypertension, took part in a 1998 observational study of low-intensity laser treatment. 51 men and 134 women were split across 4 treatment approaches, using red light at 632.8 nm, light spanning 620 to 780 nm, and near-infrared light between 780 and 1400 nm. The light was directed at the area over the liver, alongside the spine in the neck and upper back, over the main artery on the right side of the neck, or delivered as a combined water and light treatment. A positive clinical effect appeared in all 4 groups, and it seemed usable regardless of a patient's pattern of blood flow. Treatment over the neck artery and the water-based approach were singled out for patients with lower-output circulation and an overactive stress response.

Across 268 patients treated for musculoskeletal disorders at 2 clinics in Romania, a 2025 observational study tracked what happened to blood pressure during treatment. Near-infrared light at 830 nm was given for 60 seconds at 3 to 6 J/cm² and 10 Hz over the spine and major joints, 10 times across 10 days, alongside capacitive and resistive energy transfer therapy (TECAR). Upper blood pressure appeared to fall by a small but measurable amount at certain points in the course, while lower blood pressure stayed flat throughout. Patients already treated for high blood pressure and those with normal readings responded much the same, with early differences fading by day 10. The authors described both therapies as well tolerated by the heart and circulation, producing only minimal and short-lived changes in blood pressure.

Among 27 women who had undergone a mastectomy and were taking hormone-blocking drugs, a 2024 randomized controlled trial tested laser light aimed at the main artery in the neck. Red light at 660 nm was applied in contact for 15 minutes at 80 to 100 mW and 160 mW/cm², with blood pressure and heart rate measured weekly across 112 days, against a control group given no light. The trial found no statistically significant difference between the groups in either upper or lower blood pressure, though heart rate fell from 81.3 to 62.1 beats per minute in the treated group against a flat 74.1 to 75.1 in the control group. Upper blood pressure did drop from 142.3 to 116.4 mmHg in the treated group, but the trial's own results reported that change was not statistically significant.

In 2021, a pilot randomized controlled trial tested red laser light aimed at the blood through the skin or through the lining of the mouth and nose. The 36 participants were women aged 35 to 55, screened to exclude anyone with a history of high blood pressure, diabetes, or heart disease, and were split into 6 groups of 6, with 1 group left untreated. The 5 treated groups received 660 nm light at 100 mW, or at 50 mW from 2 diodes, over an artery in the wrist, under the tongue, or inside the nose, for 30 minutes and 180 J per session, twice a week across 8 weeks or as 2 blocks of 10 daily sessions. No blood pressure statistics were reported, only a spread of readings across the 36 women running from 90 to 189 mmHg on the upper number and 54 to 175 on the lower. 1 woman on the extended course finished with markedly higher readings at 30 and 60 days than she started with, a result the researchers called surprising, yet the authors concluded the approach can be safely used alongside existing methods.

Whether stimulating 2 acupuncture points with a laser could lower blood pressure was tested in a 2008 randomized controlled trial at a chiropractic college. 45 students and staff were split into a group receiving 685 nm red light at 30 mW and a control group given a sham device with the power switched off. Each active session delivered 16 J across 8 minutes, divided between acupuncture points LI4 and LI11. Across 90 days and at least 12 treatments each, the trial found average upper blood pressure fell from 129.6 to 122.5 mmHg and lower blood pressure from 85.6 to 77.2 mmHg. Body weight edged down in the treated group without reaching significance, and the natural variation in time between heartbeats did not change.