THE CURE INDEX
Helio Cure's evidence score based on human clinical trials for red light therapy.
Heart failure is a long-term condition in which the heart cannot pump blood strongly enough to meet the body's needs.
A review of 5 human studies covering 120 participants found red light therapy to be not effective for heart failure. The CURE Index scored heart failure 12 out of 100, indicating limited confidence.
Red light therapy was not associated with a consistent improvement in exercise capacity or in the strength of the heart's pumping.
The 5 studies were 1 randomized controlled trial, 2 clinical trials, and 2 observational studies. 2 studies reported partially effective outcomes, and 3 found no significant benefit.
The most cited wavelength was 905 nm, within a narrow range of 658 to 905 nm. Sessions lasted 30 to 60 seconds, were given 1 to 15 times per week, and ran across 1 to 70 days.
EVIDENCE AT A GLANCE
The numbers behind the verdict.
MOST CITED WAVELENGTH
The wavelength appearing most often in studies that showed benefit for heart failure.
905 nmTREATMENT PROTOCOL RANGES
The lowest and highest values used across heart failure studies.
| PARAMETER | RANGE |
|---|---|
| Wavelength | 658-905 nm |
| Session Duration | 30-60 seconds |
| Session Frequency | 1-15 per week |
| Therapy Duration | 1-70 days |
Note: We have excluded meta-analyses and reviews from scoring, but the list of human studies below contains them for your reference.
6 Human Studies on Red Light Therapy for Heart Failure
10 Advanced Heart Failure Patients Walked Further After Laser Therapy
Among 10 people with advanced heart failure caused by poor blood supply to the heart muscle, a 2024 observational study tested photobiomodulation (PBM) delivered both through the skin and inside a vein. 9 of the 10 were men, at an average age of 63.2 years, and each had 15 sessions of red light at 658 nm and near-infrared light at 810 nm across 15 days, with walking distance, breathlessness, and an ultrasound scan of the heart reassessed 3 months later. Distance walked in 6 minutes improved by a meaningful margin, while the share of blood the heart pumped out with each beat rose only slightly and that change was not statistically significant. Patients whose walking improved most also tended to report the largest improvement in breathlessness.
- Study Type
- Observational Study
- Participants
- 10
- Treated Area
- Chest
- Wavelength(s)
- 658, 810 nm
- Session Frequency
- 15 per week
- Therapy Duration
- 15 days
- Study Scope
- Congestive Heart Failure
Study Title: Evaluation of Photobiomodulation on myocardial function of patients with advanced ischemic cardiomyopathy, A case series.
Review Found Laser Therapy Promising but Unproven for Heart Failure
In 2023, a review examined whether photobiomodulation (PBM), also called low-level laser therapy, could help treat heart failure and heart attack. The authors searched 3 literature databases and drew on 19 studies covering 319 participants, spanning wavelengths from 630 to 900 nm and doses between 1.1 and 22.5 J/cm², applied to sites including the heart and the legs. According to the review, the collected evidence pointed to anti-inflammatory, anti-scarring and vessel-forming effects that might slow the decline seen in heart failure. The included work covered both animal and human studies, and the authors called for further research before treatment protocols could be settled.
- Study Type
- Review
- Participants
- 319
- Treated Area
- Heart And Leg
- Wavelength(s)
- 630, 630-900, 660, 808, 850 nm
- Session Duration
- 5.25 seconds, 36.75 seconds, 60 seconds, 2 minutes
- Session Frequency
- 5 per week
- Study Scope
- Myocardial Infarction
Study Title: Exploring the Potential of Energy-Based Therapeutics (Photobiomodulation/Low-Level Laser Light Therapy) in Cardiovascular Disorders: A Review and Perspective.
Laser Therapy Eased Effort but Not Walking in Heart Failure
20 hospitalized patients with heart failure took part in a 2016 randomized controlled trial of low-level laser therapy (LLLT) given to the legs before a walking test. All had hearts pumping out less than 45% of their blood with each beat, and they were split evenly between real and placebo treatment. The 10 given real light received a single 40-second application of 808 nm from a multi-diode cluster probe held against the middle of the front of the thigh, delivering 100 mW, 28 J and 91 J/cm². Both groups walked further than they had at the start, with no meaningful difference between them, but only the group given real light reported that the effort felt easier. A blood marker that builds up during muscle effort rose after exercise in the placebo group and appeared to hold steady in the treated group.
- Study Type
- Randomized Controlled Trial
- Participants
- 20
- Treated Area
- Thigh
- Wavelength(s)
- 808 nm
- Distance
- Contact
- Session Duration
- 40 seconds
- Session Frequency
- 1 per week
- Therapy Duration
- 1 day
- Study Scope
- Systolic Heart Failure
Study Title: Acute effects of low-level laser therapy irradiation on blood lactate and muscle fatigue perception in hospitalized patients with heart failure-a pilot study.
No Added Benefit was Found in Heart Failure With Added Laser Therapy
Comparing 5 groups made up of moderate or high-intensity training, each with and without added light, alongside a control group, a 2025 clinical trial tested photobiomodulation therapy (PBMT) for exercise capacity in heart failure. 49 patients averaging 62.7 years of age, all with hearts pumping out less than 40% of their blood with each beat, trained across 70 days, with the light groups receiving 810 nm at 360 J in contact with the thigh and calf muscles 3 times per week. No relevant extra benefit came from adding light to either level of training. The trial found that high-intensity training on its own raised peak oxygen use by 1.80 ml/kg/min and extended the time participants lasted before exhaustion.
- Study Type
- Clinical Trial
- Participants
- 49
- Treated Area
- Lower Limbs
- Wavelength(s)
- 810 nm
- Distance
- Contact
- Session Frequency
- 3 per week
- Therapy Duration
- 70 days
Study Title: Photobiomodulation Combined with Moderate or High-Intensity Interval Training on Oxygen Consumption and Exercise Tolerance in Patients with Heart Failure.
Heart Failure Symptoms and Walking Distance Improved After Laser Therapy
Distance walked in 6 minutes rose from an average of 148.6 to 385.1 meters in a 2023 observational study of low-level laser therapy (LLLT) in 27 people with long-standing heart failure. 21 of the 27 were men, at an average age of 57.7 years, and each had 10 sessions of 905 nm light pulsed at 500 Hz. The light was held for 60 seconds at a time on acupuncture points across the front and back of the chest and on the arm, 5 times per week across 14 days. On a standard rating of how much heart failure limits everyday activity, all 27 started in the worst or second-worst band, and 25 of them moved to a milder one. The share of blood the heart pumped out with each beat rose from 26% to 30% while the heart's filling function did not change, though the study authors cautioned that with no control group and a small sample they could draw no firm conclusion about that rise.
- Study Type
- Observational Study
- Participants
- 27
- Treated Area
- Chest And Arm
- Wavelength(s)
- 905 nm
- Distance
- Contact
- Session Duration
- 60 seconds
- Session Frequency
- 10 per week
- Therapy Duration
- 14 days
- Study Scope
- Left Ventricular Systolic Heart Failure
Study Title: Effect of low-level laser physiotherapy on left ventricular function among patients with chronic systolic heart failure.
Fatigue Unchanged After 1 Laser Therapy Session in Heart Failure
A crossover design gave each of 14 people with heart failure both a real and a placebo treatment in a 2019 double-blind clinical trial of low-level laser therapy (LLLT) for muscle fatigue. A single 30-second application of 850 nm light at 200 mW, 46 mW/cm² and 5 J per diode was held against the front of the thigh, after which participants performed repeated leg movements on a machine until they could not continue or reached 50 repetitions. Sensors reading electrical activity in the muscle picked up no change after treatment, and the trial found that 1 session did not reduce muscle fatigue in these patients.
- Study Type
- Clinical Trial
- Participants
- 14
- Treated Area
- Thigh
- Wavelength(s)
- 850 nm
- Distance
- Contact
- Session Duration
- 30 seconds
- Session Frequency
- 1 per week
- Therapy Duration
- 1 day
Study Title: Surface electromyography after lower level laser therapy application on skeletal muscles in individuals with heart failure.
The CURE Index (Clinical Understanding of Red-light Evidence) by Helio Cure is a 0-100 evidence score based on published human clinical trials. Higher scores mean stronger evidence. Read full methodology →
Data is powered by AI and reviewed by the Helio Cure team.
This page is for educational purposes only. Not medical advice. Consult a healthcare provider before starting red light therapy. Helio Cure does not diagnose, treat, or cure any medical condition.
Last updated: Aug 30, 2026