This week’s newest studies in red light therapy and photobiomodulation. See last week’s research here.
This Week in Red Light Therapy
This week brought one of the largest head-to-head comparisons of treatments for Alzheimer’s disease ever published, new data on post-surgical pain and opioid use, and a human study that challenges a widely cited assumption about how red light works.
- Alzheimer’s: A network meta-analysis of 91 trials and 12,242 participants found photobiomodulation showed significant benefits for cognitive function, outperforming drug therapy on that measure.
- Post-surgery pain: Red light therapy applied within two hours of open-heart surgery reduced pain scores and cut opioid consumption in a 264-patient cohort.
- Jaw pain: Laser therapy outperformed the standard combination of a mouth splint and medication for TMD in a 63-patient randomized trial.
- Nerve repair: A rat study found that near-infrared laser therapy restored nerve growth factor and protective myelin protein after sciatic nerve injury.
- Mechanism update: A randomized human study found that a single session of red light therapy doesn’t increase mitochondrial respiration in skin or muscle tissue, challenging one of the therapy’s most-cited proposed mechanisms.
Red Light Therapy Outperformed Drug Therapy for Alzheimer’s in a 91-Trial Analysis
The study: Gao F et al. published a Bayesian network meta-analysis in iScience comparing five treatments for Alzheimer’s disease across 91 randomized controlled trials and 12,242 participants. The five interventions were drug therapy, brain-directed red light therapy, cognitive therapy, exercise therapy, and transcranial magnetic stimulation.
What they found:
- Photobiomodulation and transcranial magnetic stimulation showed the strongest effects on cognitive function, both outperforming drug therapy on that specific outcome.
- Cognitive therapy and exercise therapy came out ahead when quality of life was the measure.
- No single intervention dominated across all outcomes – the winner depended on what was being measured.
What this means for you: If brain health is why you’re interested in red light therapy, this is one of the strongest data points yet, with 12,242 participants and a direct comparison against drug therapy. The 91 trials used varying protocols, so “photobiomodulation” here covers a range of wavelengths and session frequencies rather than one standardized approach.
Red Light After Heart Surgery Cut Pain and Opioid Use in 264 Patients
The study: Wang Y et al. published a retrospective cohort study in Pain Research & Management of 264 patients who had open-heart surgery (sternotomy). Eighty received red light therapy within two hours of surgery; 184 received standard care.
What they found:
- Acute pain incidence was 38.8% in the red light group versus 57.1% in the standard-care group.
- Pain scores were significantly lower in the treated group throughout recovery.
- Opioid consumption dropped in the photobiomodulation group, with no increase in wound complications.
What this means for you: This adds to the evidence for red light therapy in acute post-surgical pain, though as a retrospective study it shows association rather than confirmed cause and effect.
Laser Therapy Beat Splints and Medication for Jaw Pain in an RCT
The study: Djordjević et al. published a randomized controlled trial in Life (Basel) testing low-level laser therapy against standard treatment for temporomandibular disorder (TMD), a chronic jaw and oral pain condition affecting the joint where your jaw meets your skull, in 63 participants. The standard treatment was a mouth splint combined with medication.
What they found:
- Both groups saw significant pain reduction and quality-of-life improvements.
- The laser therapy group had a higher treatment success rate than the splint-and-medication group.
What this means for you: Laser therapy for jaw pain now has a direct head-to-head comparison with the current standard of care, with laser coming out ahead. The trial was small, so a larger study would add more confidence to these results.
Nerve Growth Restored After Injury in Early Red Light Research
The study: Oliveira ME et al. published a rat study in Current Issues in Molecular Biology applying 904 nm near-infrared laser therapy to rats with sciatic nerve injury. The sciatic nerve is the longest nerve in the body and a common site of neuropathy and pain in humans.
What they found:
- Treated rats showed significantly better nerve structure preservation compared to controls.
- Nerve growth factor (NGF), a protein the body uses to maintain and repair nerves, was restored to normal levels with treatment.
- Myelin protein zero (P0), which forms the insulating sheath around nerve fibers, increased significantly in the treated group.
What this means for you: This study adds molecular detail to why red light therapy may help with nerve-related pain, identifying specific proteins the treatment appears to influence.
This was an animal study — an early step in research. Results may not translate directly to humans.
A Human Study Found Red Light Doesn’t Raise Mitochondrial Activity in Muscle After One Session
The study: Aussieker T et al. published a within-participant study in Medicine and Science in Sports and Exercise. Twelve healthy adults received photobiomodulation on one leg and a sham treatment on the other. After treatment, the researchers took muscle and skin biopsies and measured mitochondrial function directly.
What they found:
- No difference in mitochondrial respiration between the treated and untreated legs in either skin or muscle.
- No difference in how well the mitochondria responded to energy demand.
- Gene expression differed for only 3 of 91 genes tested – a minimal effect.
What this means for you: A commonly proposed mechanism for red light therapy is that it directly stimulates mitochondria, the cells’ energy producers. This study tested that in humans using direct tissue measurements and didn’t find the effect, at least not from a single session.
Sources
- Gao F et al. “Comparative Effectiveness of Multiple Interventions for Alzheimer’s Disease on ABC Syndromes and QoL.” iScience, 2026. PubMed
- Wang Y et al. “Nursing-Integrated Photobiomodulation Therapy for Post-Sternotomy Pain Management.” Pain Research & Management, 2026. PubMed
- Djordjević et al. “Therapeutic Effect of Low-Level Laser Therapy in Patients with Temporomandibular Disorder.” Life (Basel), 2026. PubMed
- Oliveira ME et al. “Photobiomodulation Therapy Enhances Peripheral Nerve Repair by Restoring Nerve Growth Factor Levels and Increasing Myelin Protein Zero Expression After Chronic Constriction Injury in Rats.” Current Issues in Molecular Biology, 2026. PubMed
- Aussieker T et al. “Photobiomodulation Does Not Increase Mitochondrial Respiration in Skeletal Muscle or Skin Tissue in Humans.” Medicine and Science in Sports and Exercise, 2026. PubMed
