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Does red light therapy work? What the trials say about hair, skin and healing

Yes, for some uses: light therapy grew more hair in sham-controlled trials and eased mouth sores in cancer care. Wrinkle claims have far less support.

Published October 2026

Short answer

Yes, for some uses: in trials, red and near-infrared light grew more hair in pattern hair loss and cut severe mouth sores from cancer treatment, but the evidence for wrinkles and most pain is much weaker. Evidence grade B (Moderate). Meta-analyses of sham-controlled trials for hair loss and mouth sores; downgraded once for high variation between studies; other uses (wrinkles, pain, ulcers) are weaker.

Key takeaways

  • For pattern hair loss, a 2021 meta-analysis of 15 studies (795 people) and a 2025 meta-analysis of 38 studies (3,098 people) both found more hair with light therapy than control [1][2].
  • In a sham-controlled trial of 41 men, hair counts rose by 67.2 with a 655 nm device versus 28.4 with sham, with no side effects reported [3].
  • In head and neck cancer patients, light therapy cut the risk of severe mouth sores to about half in a meta-analysis of 14 trials (869 people) [4].
  • For diabetic foot ulcers, ulcers were more likely to heal completely in a meta-analysis of 7 small trials (194 people) [5].
  • Evidence for wrinkles is thin: a 12-week trial of 52 women found red and white LEDs improved wrinkles equally, with no placebo group [6].

The short version

Yes, red light therapy works for some uses. For pattern hair loss, light devices grew more hair than sham devices in trials, and two meta-analyses covering 15 and 38 studies agree [1][2]. For people having head and neck cancer treatment, it also reduced severe mouth sores [4]. The case for wrinkles and most pain is much weaker [6][7].

What the studies show

Hair loss. A 2021 meta-analysis of 15 studies (795 people) found more hair density with light therapy than with control [1]. A 2025 meta-analysis of 38 studies (3,098 people, mostly with pattern hair loss) found the same, after 4 to 26 weeks [2]. In a sham-controlled trial of 41 men using a 655 nm laser and LED device, hair counts rose by 67.2 with the device versus 28.4 with sham, and no side effects were reported [3]. A similar trial in 42 women found hair counts rose by 100.3 with the device versus 23.9 with sham [8]. In a 24-week trial of 100 people, treated scalp had 14.2% hair coverage versus 11.8% on the sham side [9].

Mouth sores from cancer treatment. A 2024 meta-analysis of 14 trials (869 head and neck cancer patients) found light therapy cut the risk of severe oral mucositis, painful mouth sores caused by radiation or chemotherapy, to about half (risk ratio 0.45, 95% CI 0.24 to 0.85), and also eased the pain [4]. The best results came from clinic lasers at 10 to 25 mW [4].

Healing diabetic foot ulcers. A meta-analysis of 7 trials (194 people) found ulcers were more likely to heal completely with light therapy (odds ratio 6.72, 95% CI 1.99 to 22.64) [5]. A later meta-analysis of 12 trials reported ulcers were 4.65 times more likely to heal completely [10].

Wrinkles. In a 12-week trial of 52 women, red LEDs (660 nm) and white LEDs both improved wrinkles around the eyes, with no statistically significant difference between them and no placebo group [6].

The nuances

Results vary a lot. Both hair meta-analyses reported high variation between studies [2][11], and the mouth-sore analysis did too [4].

Use matters. A 2025 expert consensus (21 specialists) judged photobiomodulation, the technical name for this therapy, effective for peripheral neuropathy, androgenic alopecia, wound ulcers, pressure ulcers, diabetic foot ulcer pain and radiation burns of the skin [12]. A 2021 meta-analysis found very low-certainty evidence that it prevents severe radiation dermatitis [13].

Pain is mixed. A meta-analysis of 9 small trials (325 people) found low-level laser eased fibromyalgia pain compared with placebo, but the trials were of low to middle quality [7]. For Achilles tendon pain, 4 trials (119 people) gave low to very low certainty evidence that did not support routine use [14].

Hair loss comparisons. A trial in women found light therapy gave results comparable to 5% minoxidil, and the combination did best [15]. A meta-analysis of 15 trials of minoxidil combinations found that adding light therapy to minoxidil increased hair count more than minoxidil alone [16].

Safety. The consensus panel judged red light therapy safe for adults, with no DNA damage from red light [12]. A systematic review of oncologic safety found no clinical trial data linking it to new or recurrent cancer [17].

What this means for you

The best-supported uses are pattern hair loss and, in clinics, mouth sores during cancer treatment [2][4]. Devices and wavelengths differ between trials, and one meta-analysis found laser-only devices did better than laser and LED combinations [1]. If you are considering it for a medical problem such as a foot ulcer or cancer treatment, ask your care team first. For more, see Red Light Therapy and Minoxidil.

Go deeper

  • Red Light Therapy — Red and near-infrared light therapy grew more hair than sham devices in people with pattern hair loss across two large meta-analyses, and it reduced severe mou…
  • Minoxidil — Low-dose oral minoxidil regrows hair in men with male pattern hair loss about as well as the foam or liquid used on the scalp.

References

  1. Meta-analysis of photobiomodulation for the treatment of androgenetic alopecia.. J Dermatolog Treat, 2021.
  2. Low-Level Laser and LED Therapy in Alopecia: A Systematic Review and Meta-Analysis.. Dermatol Surg, 2025.
  3. The growth of human scalp hair mediated by visible red light laser and LED sources in males.. Lasers Surg Med, 2013.
  4. Efficacy of photobiomodulation therapy in the management of oral mucositis in patients with head and neck cancer: A systematic review and meta-analysis of randomized controlled trials.. Head Neck, 2024.
  5. Efficacy of low-level light therapy for treatment of diabetic foot ulcer: A systematic review and meta-analysis of randomized controlled trials.. Diabetes Res Clin Pract, 2018.
  6. The Efficacy and Safety of 660 nm and 411 to 777 nm Light-Emitting Devices for Treating Wrinkles.. Dermatol Surg, 2017.
  7. Low-Level Laser Therapy for Fibromyalgia: A Systematic Review and Meta-Analysis.. Pain Physician, 2019.
  8. The growth of human scalp hair in females using visible red light laser and LED sources.. Lasers Surg Med, 2014.
  9. Efficacy and Safety of a Low-Level Light Therapy for Androgenetic Alopecia: A 24-Week, Randomized, Double-Blind, Self-Comparison, Sham Device-Controlled Trial.. Dermatol Surg, 2018.
  10. Efficacy of low-level light therapy for improving healing of diabetic foot ulcers: A systematic review and meta-analysis of randomized controlled trials.. Wound Repair Regen, 2021.
  11. The effectiveness of treatments for androgenetic alopecia: A systematic review and meta-analysis.. J Am Acad Dermatol, 2017.
  12. Evidence-based consensus on the clinical application of photobiomodulation.. J Am Acad Dermatol, 2025.
  13. Effectiveness of photobiomodulation therapy in radiation dermatitis: A systematic review and meta-analysis.. Crit Rev Oncol Hematol, 2021.
  14. Photobiomodulation with low-level laser therapy for treating Achilles tendinopathy: a systematic review and meta-analysis.. Clin Rehabil, 2020.
  15. Low level light-minoxidil 5% combination versus either therapeutic modality alone in management of female patterned hair loss: A randomized controlled study.. Lasers Surg Med, 2017.
  16. The effectiveness of combination therapies for androgenetic alopecia: A systematic review and meta-analysis.. Dermatol Ther, 2020.
  17. Photobiomodulation: A Systematic Review of the Oncologic Safety of Low-Level Light Therapy for Aesthetic Skin Rejuvenation.. Aesthet Surg J, 2023.