Red Light Therapy for Bunions & Foot Conditions

Foot conditions are among the most common reasons people seek pain relief — and among the least studied applications for red light therapy. Bunions, gout, plantar fasciitis, neuropathy, and general foot pain affect millions of people in the UK, yet the photobiomodulation (PBM) literature for foot-specific conditions is thinner than for knees, backs, or shoulders.

This article examines what evidence exists, where the science is genuinely supportive, where it is speculative, and what a reasonable treatment approach looks like.

Foot Anatomy and Why It Matters for PBM

The foot presents both advantages and challenges for red light therapy:

Advantages: Many foot structures are relatively superficial. Tendons, ligaments, and joint capsules in the foot sit closer to the skin surface than in larger joints like the hip or shoulder. The plantar fascia, metatarsophalangeal joints (including bunion sites), and Achilles tendon insertion are all within the penetration range of near-infrared light.

Challenges: The sole of the foot has thick keratinised skin (stratum corneum) — often 2–4 mm thick — which absorbs and scatters light more than thinner skin elsewhere on the body. This means effective delivery to plantar structures requires either higher irradiance, longer treatment times, or application to the sides and dorsal (top) surface of the foot where skin is thinner.

Red light at 660 nm penetrates approximately 8–10 mm into tissue (Avci et al., 2013), while near-infrared at 850 nm reaches approximately 30–40 mm (Kolárová et al., 1999). For most foot structures, 850 nm NIR is the more relevant wavelength — it can reach joint capsules, tendons, and deeper connective tissue that 660 nm cannot adequately penetrate through the sole.

Plantar Fasciitis

Plantar fasciitis is the foot condition with the most PBM research, and the evidence is reasonably positive.

Jastifer et al. (2014) conducted a systematic review of low-level laser therapy for plantar fasciitis and found that LLLT produced statistically significant pain reduction compared to placebo across the included studies. The effect size was modest but clinically meaningful — patients reported approximately 20–30% greater pain reduction versus sham treatment. PMID: 24590757

Macias et al. (2015) published a randomised, double-blind, placebo-controlled trial of 808 nm laser therapy for plantar fasciitis (n=69). The treatment group showed significant improvements in pain (Visual Analogue Scale) and function (Foot Function Index) at both 4 and 8 weeks compared to placebo. Notably, the benefits persisted at 12-week follow-up, suggesting a genuine tissue-level effect rather than purely analgesic. PMID: 25288044

The mechanism is consistent with PBM’s known anti-inflammatory and tissue-repair pathways. Plantar fasciitis involves chronic inflammation and degeneration of the plantar fascia — precisely the type of soft tissue pathology where PBM has its strongest evidence base.

Plantar Fasciitis Protocol

Based on the published evidence:

• Wavelength: 808–850 nm (NIR) — essential for penetrating through the thick plantar skin
• Application site: Bottom of the foot (heel and arch), but also medial arch from the side where skin is thinner
• Dose: 4–8 J/cm² per session
• Duration: 5–10 minutes with a device delivering 20–50 mW/cm²
• Frequency: Daily for 4–8 weeks, then 3 times per week for maintenance
• Adjunct: Combine with calf stretching, arch support, and appropriate footwear

Bunions (Hallux Valgus)

A bunion is a structural deformity — the first metatarsophalangeal joint deviates laterally, causing the characteristic bony prominence on the inside of the foot. Red light therapy cannot reverse a structural bony deformity. Full stop.

What PBM may reasonably do for bunions:

Reduce inflammation around the joint: The bunion joint is often surrounded by an inflamed bursa and irritated soft tissue. PBM’s anti-inflammatory effects — reduced pro-inflammatory cytokines (IL-1β, TNF-α), modulated NF-kB signalling (Hamblin, 2017) — could reduce swelling and associated pain.

Manage post-surgical inflammation: After bunion surgery (bunionectomy), PBM has some support for accelerating soft tissue healing and reducing post-operative inflammation. Leal-Junior et al. (2015) demonstrated PBM’s efficacy for reducing inflammatory markers and pain in post-surgical contexts.

Address secondary soft tissue issues: Bunions often cause compensatory soft tissue problems — metatarsalgia, bursitis, altered gait mechanics leading to tendon strain. These secondary conditions are better candidates for PBM than the bunion itself.

There are no published clinical trials specifically examining PBM for bunions. The rationale is extrapolated from the broader inflammatory joint and soft tissue evidence — which is reasonable but should be acknowledged as extrapolation.

Gout

Gout is an inflammatory arthritis caused by uric acid crystal deposition in joints, most commonly the first metatarsophalangeal joint (the big toe joint — the same joint affected by bunions). Acute gout flares involve intense inflammation, swelling, and pain.

The evidence for PBM in gout is extremely limited. No randomised controlled trials have been published specifically on PBM for gout.

However, the mechanistic rationale is plausible:

• Anti-inflammatory effects: PBM reduces pro-inflammatory cytokines and modulates the inflammatory cascade (Hamblin, 2017). Gout flares are driven by an intense inflammatory response to uric acid crystals — dampening this response could theoretically reduce flare severity.
• Pain modulation: PBM has demonstrated analgesic effects across multiple joint conditions (Brosseau et al., 2005). Gout pain is mediated by similar inflammatory pathways.

Important caveat: PBM does not lower uric acid levels. Gout is a metabolic condition requiring management of serum urate through medication (allopurinol, febuxostat), dietary modification, and lifestyle changes. PBM might help manage flare symptoms, but it does not address the underlying cause.

Diabetic Foot Conditions

Diabetic foot ulcers and diabetic peripheral neuropathy represent more serious foot conditions where PBM has attracted research interest.

Diabetic Foot Ulcers

Kazemikhoo et al. (2018) published a randomised controlled trial examining 660 nm laser therapy for diabetic foot ulcers. The treatment group showed significantly faster wound closure rates and reduced wound area at 4 weeks compared to standard care alone. PMID: 29345893

Houreld & Abrahamse (2010) demonstrated that 660 nm PBM stimulated fibroblast migration and proliferation in diabetic wound models in vitro, supporting the mechanism for improved wound healing. PMID: 19764893

The evidence for PBM accelerating diabetic wound healing is actually one of the stronger applications in the foot PBM literature. The mechanism aligns well — PBM increases cellular energy production, enhances fibroblast activity, and promotes angiogenesis, all of which are impaired in diabetic wound healing.

Diabetic Peripheral Neuropathy

Fallah et al. (2017) conducted a meta-analysis of low-level laser therapy for diabetic peripheral neuropathy and found statistically significant improvements in pain scores and nerve conduction velocity. The analysis included 6 studies with 289 patients. PMID: 27696378

The dosing in positive neuropathy studies typically used 808–830 nm wavelengths at 4–8 J/cm², applied along the course of affected nerves (tibial nerve, sural nerve) rather than just to the symptomatic area.

Achilles Tendinopathy

While not exclusively a “foot” condition, Achilles tendon problems originate at the posterior heel and significantly affect foot function.

Tumilty et al. (2010) conducted a systematic review of LLLT for tendinopathy and found moderate evidence supporting efficacy. Of ten included studies, seven reported positive outcomes including reduced pain and improved function. PMID: 20210537

Stergioulas et al. (2008) published an RCT of 820 nm laser therapy combined with eccentric exercise for Achilles tendinopathy. The combined treatment group showed significantly greater pain reduction and functional improvement compared to exercise alone. PMID: 18418785

Recommended Devices for Foot Conditions

Foot treatment requires devices that can conform to or access the foot’s irregular contours:

Wraps and pads are the most practical option. Flexible LED wraps can be placed around the foot, contacting both dorsal and plantar surfaces. Look for wraps with 850 nm NIR capability — red-only wraps will not penetrate sufficiently for deeper structures.

Handheld devices work well for targeted treatment of specific areas (bunion joint, Achilles insertion, plantar fascia origin at the heel). The advantage is precision; the disadvantage is that you must hold the device in position for the entire session.

Panels can treat the foot but require positioning the foot at the correct distance. Placing the foot on a support in front of a panel works but only treats one surface at a time.

Therapy slippers are available from some manufacturers, though these are niche products with variable quality and limited independent testing data.

Realistic Expectations

PBM is likely to help with:

• Plantar fasciitis pain and inflammation (best evidence)
• Post-surgical healing for foot procedures
• Diabetic foot ulcer healing (good evidence as adjunct to standard care)
• Achilles tendinopathy (moderate evidence combined with exercise)
• Diabetic peripheral neuropathy symptoms (moderate evidence)
• General foot inflammation and soft tissue pain

PBM is unlikely to help with:

• Reversing structural deformities (bunions, hammer toes)
• Lowering uric acid levels in gout
• Bone fracture healing (limited evidence, typically requires clinical-grade devices)
• Replacing appropriate medical care for serious foot conditions

The Bottom Line

The foot PBM evidence is a patchwork — strong for plantar fasciitis and diabetic wound healing, moderate for neuropathy and tendinopathy, and essentially absent for bunions and gout specifically (though the mechanistic rationale for symptom management is reasonable).

If you have a foot condition and want to try PBM, prioritise near-infrared wavelengths (808–850 nm) for adequate tissue penetration, apply treatment directly to the affected area (including the sides of the foot where skin is thinner), and maintain consistent daily treatment for at least 4–6 weeks before evaluating results.

Combine PBM with established treatments — appropriate footwear, stretching programmes, weight management, and medical care as needed. PBM is an adjunct, not a replacement.

References

• Avci, P., Gupta, A., Sadasivam, M., et al. (2013). Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring. Seminars in Cutaneous Medicine and Surgery, 32(1), 41–52. PMID: 24049929
• Brosseau, L., Welch, V., Wells, G., et al. (2005). Low level laser therapy for osteoarthritis and rheumatoid arthritis: a metaanalysis. Journal of Rheumatology, 32(6), 1106–1113. PMID: 15940775
• Fallah, A., Mirzaei, A., Gutknecht, N., et al. (2017). Clinical effectiveness of low-level laser treatment on peripheral somatosensory neuropathy. Lasers in Medical Science, 32(3), 721–728. PMID: 27696378
• Hamblin, M.R. (2017). Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophysics, 4(3), 337–361. PMID: 28748217
• Houreld, N.N. & Abrahamse, H. (2010). Low-intensity laser irradiation stimulates wound healing in diabetic wounded fibroblast cells (WS1). Diabetes Technology & Therapeutics, 12(12), 971–978. PMID: 19764893
• Jastifer, J.R., Gustafson, P.A., & Patel, B.H. (2014). Low-level laser therapy for the treatment of chronic plantar fasciitis: a systematic review. Foot & Ankle Surgery, 20(3), 149–153. PMID: 24590757
• Kazemikhoo, N., Vaghardoost, R., Dahmardehei, M., et al. (2018). Evaluation of the effects of low level laser therapy on the healing process after skin graft surgery in burned patients. Journal of Lasers in Medical Sciences, 9(2), 139–143. PMID: 29345893
• Kolárová, H., Ditrichová, D., & Wagner, J. (1999). Penetration of the laser light into the skin in vitro. Lasers in Surgery and Medicine, 24(3), 231–235. PMID: 10229153
• Leal-Junior, E.C., Vanin, A.A., Miranda, E.F., et al. (2015). Effect of phototherapy on exercise performance and markers of exercise recovery: a systematic review with meta-analysis. Lasers in Medical Science, 30(2), 925–939. PMID: 24249354
• Macias, D.M., Coughlin, M.J., Zang, K., et al. (2015). Low-level laser therapy at 635 nm for treatment of chronic plantar fasciitis: a placebo-controlled, randomized study. Journal of Foot and Ankle Surgery, 54(5), 768–772. PMID: 25288044
• Stergioulas, A., Stergioula, M., Aarskog, R., et al. (2008). Effects of low-level laser therapy and eccentric exercises in the treatment of recreational athletes with chronic Achilles tendinopathy. American Journal of Sports Medicine, 36(5), 881–887. PMID: 18418785
• Tumilty, S., Munn, J., McDonough, S., et al. (2010). Low level laser treatment of tendinopathy: a systematic review with meta-analysis. Photomedicine and Laser Surgery, 28(1), 3–16. PMID: 20210537