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The Science
Research, studies & what the evidence says.
Recovery, Inflammation & Musculoskeletal Health
Effectiveness of Photobiomodulation in Reducing Pain and Disability in Patients With Knee Osteoarthritis: A Systematic Review With Meta-Analysis
- What was studied
- 10 randomized placebo-controlled trials (542 participants) comparing photobiomodulation with placebo in people with knee osteoarthritis.
- What it found
- Pain at rest was lower with photobiomodulation than placebo (−0.7, 95% CI −1.1 to −0.2), a moderate effect. The Timed Up and Go walking test showed no significant difference.
- Limitations
- The certainty of the evidence was rated very low, and every included study had unclear to high risk of bias. Improvements within the treated groups were not always clinically meaningful once compared with placebo. The authors call for more research on dosing, including for other types of light emitters.
Effects of Photomodulation Therapy for Delayed Onset Muscle Soreness: A Systematic Review and Meta-Analysis
- What was studied
- 14 controlled studies of light therapy (660 to 950 nm) applied after exercise-induced muscle soreness. Only 4 reported enough data to be pooled for soreness and strength.
- What it found
- Soreness scores were lower than placebo at 72 and 96 hours (pooled effect about −0.55, moderate). Strength recovery was better at 24 and 48 hours (pooled effect about 0.97 to 0.99, large). 4 of the 14 studies found no significant effect.
- Limitations
- Only 4 studies could be pooled, and heterogeneity between them was substantial. The studies used different devices, wavelengths, and doses, and their quality scores ranged from 4 to 9 out of 10. The authors say more high-quality trials with defined parameters are needed.
Photobiomodulation therapy with light-emitting diode does not improve lower-body muscle performance and delayed-onset muscle soreness in resistance-trained women: A randomized, controlled, crossover trial
- What was studied
- Whether a single session of 940 nm LED therapy changed lower-body muscle performance to exhaustion, perceived exertion, or muscle soreness in resistance-trained women, using a randomized crossover design with a control condition.
- What it found
- It did not. LED therapy did not improve performance, perceived exertion, or soreness compared with placebo.
- Limitations
- This tested one session at one wavelength (940 nm), so it says little about other wavelengths, doses, or repeated use.
Skin Health & Aging
A prospective, randomized, placebo-controlled, double-blinded, and split-face clinical study on LED phototherapy for skin rejuvenation: clinical, profilometric, histologic, ultrastructural, and biochemical evaluations and comparison of three different treatment settings
- What was studied
- 76 people with facial wrinkles had one half of the face treated with LED devices (the authors concluded 830 and 633 nm) at three different settings, compared with a control. Assessments by the participants and investigators were double-blinded.
- What it found
- Measured wrinkle depth fell by up to 36% and skin elasticity rose by up to 19% compared with baseline in the three treatment groups. Tissue and biochemical markers also changed. No adverse effects were reported.
- Limitations
- Results are reported against each person’s own baseline, so the benefit beyond placebo is harder to judge from the abstract. A single 2007 study using specific devices and settings.
Other Wellness Research
Efficacy and safety of a low-level laser device in the treatment of male and female pattern hair loss: a multicenter, randomized, sham device-controlled, double-blind study
- What was studied
- 269 men and women with pattern hair loss were randomized to a low-level laser comb or a sham device, used on the scalp three times a week for 26 weeks. Participants and site investigators were blinded.
- What it found
- At 26 weeks, terminal hair count rose by about 18 to 26 per cm² with the laser comb versus about 2 to 9 per cm² with sham, depending on the group. No serious adverse events were reported.
- Limitations
- The device was a laser comb, not an LED panel or cap. The manufacturer partly funded the study and supplied the devices. 44 participants were lost to follow-up, and the authors say longer-term studies are needed to see whether results last.
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Things I Actually Use
Fitness, skincare, wellness & everyday favorites.
Favorites are coming soon.
@elizabeth.lewis.fit
Crunchy where it counts. Spicy everywhere else.
Biomedical engineer. Helio founder. Fitness, science, wellness & everything in between.
What I’m building
Helio Aesthetics is my red light therapy and recovery brand, built around the science of photobiomodulation. Visit our Hudson Valley studio for full-body sessions, or explore our red and near-infrared light devices for at-home and veterinary wellness.
Visit Helio Hudson10-minute full-body red light therapy sessions in Eastdale Village, Poughkeepsie, NY.
Shop Helio DevicesRed and near-infrared light devices for personal and veterinary wellness.
Helio products are general wellness devices and are not intended to diagnose, treat, cure, or prevent any disease.
What I’m into
Helio on Instagram: @helio.aesthetics and @helio.aesthetics.hudson
