This week’s newest studies in red light therapy and photobiomodulation. See last week’s research here.
This Week in Red Light Therapy
Brain, recovery, and pain dominated this week’s research, with one study going head-to-head between laser therapy and steroid injections.
- Study 1: LLLT matched corticosteroid injections for carpal tunnel pain in 163 patients, without the steroid side effects
- Study 2: A Harvard team pooled 8 Parkinson’s trials and found PBM was safe but hasn’t yet shown a statistically significant motor benefit
- Study 3: A wearable PBM patch improved some jump metrics in young tennis players, though the evidence is still preliminary
- Study 4: A meta-analysis of 32 dental implant trials found PBM consistently cut post-op pain
- Study 5: Female rats recovered better from neuropathic pain with PBM than males, pointing to a hormonal factor
- Study 6: Combining LLLT with stem cell exosomes outperformed either treatment alone for Achilles tendon repair in rabbits
LLLT Matched Steroid Injections for Carpal Tunnel Relief
The study: A multicenter retrospective study across Chinese hospitals assigned 163 carpal tunnel syndrome patients to one of three treatments: ultrasound-guided acupotomy (a minimally invasive release) plus low-level He-Ne laser therapy (n=54), acupotomy plus corticosteroid injection (n=55), or acupotomy alone (n=54), with 16 weeks of follow-up.
What they found:
- All three groups improved significantly in pain, function, and nerve conduction measurements
- Both the laser group and the steroid group outperformed acupotomy alone on pain and functional outcomes at 1, 4, and 16 weeks
- No significant differences in pain scores between the laser and steroid groups at any follow-up point
- Six patients in the steroid group developed hyperglycemia; no adverse events were reported in the laser group
What this means for you: For people who can’t take steroids, or want to avoid steroid side effects, laser therapy combined with acupotomy appears to produce comparable pain and function outcomes. Neuropathy is one of the more clinically supported uses of light therapy, and this adds another controlled comparison.
Multicenter retrospective study, non-randomized, peer-reviewed; results are consistent but need a proper RCT to confirm.
PBM for Parkinson’s: Safe but Motor Benefit Still Unproven
The study: A Harvard Medical School team at Spaulding Rehabilitation Hospital conducted a PRISMA-compliant systematic review and meta-analysis of 8 trials involving 279 people with Parkinson’s disease, evaluating red and near-infrared light therapy for brain health and motor function.
What they found:
- PBM was safe and well tolerated across all trials, with only minor side effects
- Meta-analysis of 4 RCTs found no statistically significant effect on the standard motor score (MDS-UPDRS-III: mean difference -1.37 points, 95% CI: -5.55 to 2.80)
- Individual effect sizes ranged from negligible (d=0.03) to small-to-moderate (d=0.41), with direction consistently favoring PBM
- Major limitation: wide variation in devices, wavelengths, and treatment protocols across studies made pooling difficult
What this means for you: PBM appears safe as an add-on for Parkinson’s, but the current evidence doesn’t show it meaningfully improves motor symptoms. Standardized, larger trials are the next step. A null result here isn’t a verdict; it’s a “not yet”.
Systematic review with meta-analysis, Cochrane risk-of-bias tools, PROSPERO-registered; limited by small samples and heterogeneous protocols across included studies.
Wearable PBM Patch Showed Promising Results in Young Tennis Players
The study: Italian researchers applied the Taopatch wearable photobiomodulation device to 28 young tennis players (age 14.41 +/- 2.60 years; 11 female, 17 male) for 15 minutes and measured jump performance and reaction time before and after.
What they found:
- Squat Jump flight time and maximal pre-take-off velocity improved after application
- Countermovement jump concentric work also increased
- Several improvements survived one statistical correction method but not a more conservative one
- Reaction time and stiffness responses didn’t change significantly
What this means for you: The results are interesting but fragile. No sham control means it’s impossible to rule out a warm-up effect, and the stats depend heavily on which correction you apply. For athletes exploring recovery tools, wearable PBM is worth watching, but this one study isn’t enough to draw conclusions.
Small pilot study, no sham control, uncontrolled design; statistical significance depended on the correction method applied.
Large Meta-Analysis Finds PBM Cuts Post-Op Pain After Dental Implants
The study: Brazilian researchers pooled 32 randomized controlled trials involving 829 patients and 1,278 implants to evaluate photobiomodulation as a supportive treatment in dental implant surgery.
What they found:
- PBM consistently reduced postoperative pain (mean difference -0.27 on a 0-10 scale) across studies
- Early implant stability (measured by resonance frequency) improved significantly in the PBM group (ISQ mean difference +1.26)
- Marginal bone loss showed a small but statistically significant reduction (-0.09 mm)
- GRADE certainty of evidence: low to very low, largely due to heterogeneous laser protocols across studies
What this means for you: Across 32 trials, the pain reduction pattern was consistent. The effect sizes are modest but real. Oral health is a growing application area, and this is some of the strongest evidence yet for a practical use case. The low GRADE rating reflects inconsistent protocols, not inconsistent results.
Meta-analysis of 32 RCTs, PRISMA guidelines, GRADE certainty assessment; downgraded by high heterogeneity in treatment protocols.
Female Rats Responded Better to PBM for Nerve Pain Than Males
The study: Brazilian researchers at the University of Sao Paulo tested infrared PBM in male and female rats with chronic constriction injury of the sciatic nerve, a standard neuropathic pain model. Animals received 10 treatment sessions, 3 times per week, and pain responses were tracked throughout.
What they found:
- PBM progressively reduced pain behaviors in both sexes
- Females showed greater relative recovery in both pain measures (mechanical hyperalgesia and tactile allodynia)
- Males maintained higher absolute pain thresholds throughout the study
- Estrous cycle phase influenced pain sensitivity, with lower pain during metestrus compared to estrus and proestrus
What this means for you: Both sexes responded to treatment, but the response pattern differed. The finding that hormonal cycle phase affected sensitivity adds a layer that human trials rarely measure. If you’re tracking your own response to light therapy for chronic pain, this suggests biological sex and cycle timing could be worth noting.
Animal study (rat model); early-stage research that may not translate directly to humans.
Combining LLLT with Stem Cell Exosomes Accelerated Achilles Tendon Healing in Rabbits
The study: Iranian researchers induced a partial Achilles tendon injury in rabbits and compared four recovery protocols: no treatment, LLLT alone (830nm), adipose-derived exosome injection alone, and combined LLLT plus exosomes. Treatments were applied on days 1, 8, and 15, with ultrasound and histology assessments at day 21.
What they found:
- The combined LLLT plus exosome group showed significantly greater force generation during flexion and dorsiflexion at day 21 (P < 0.05)
- Tendon and muscle elasticity (measured by ultrasound) improved most in the combination group
- Histology showed compact, parallel collagen fibers and a well-organized tissue structure in the combined group
- No inflammation was observed, and muscle atrophy was reduced
What this means for you: Neither treatment alone produced the same result as the combination. The exosome piece is far from clinical availability, but it suggests LLLT may work synergistically with regenerative therapies. For current tendonitis management, LLLT alone still showed improvements over the control group.
Animal study (rat model); early-stage research that may not translate directly to humans.
Sources
- Shang X, et al. “Ultrasound-Guided Low-Level He-Ne Laser Therapy Following Acupotomy Release for Carpal Tunnel Syndrome: A Multicenter Retrospective Study.” Journal of Pain Research, 2026. PubMed
- Mariano J, et al. “Efficacy and Safety of Photobiomodulation Therapy for Motor Symptoms in Parkinson’s Disease: A Systematic Review and Meta-Analysis.” Brain Sciences, 2026. PubMed
- Grossi A, et al. “Preliminary pre-post changes in neuromuscular performance after application of a wearable photobiomodulation device in young tennis athletes.” European Journal of Translational Myology, 2026. PubMed
- Mateus OTMV, et al. “Photobiomodulation in Dental Implant Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.” Dentistry Journal, 2026. PubMed
- Marques NF, et al. “Sex-related analgesic responses to photobiomodulation therapy in rats with neuropathic pain.” Lasers in Medical Science, 2026. PubMed
- Sabah Majeed A, et al. “Combined photobiomodulation and exosome therapy for muscle and tendon regeneration: an experimental rabbit study.” Lasers in Medical Science, 2026. PubMed
