Red Light Therapy and Cancer

Researched and written by Keith Bishop, Clinical Nutritionist, Cancer Coach, Author, and Retired Pharmacist

Introduction: What is Red Light Therapy?

Red light therapy (RLT), also known as Photobiomodulation, is a non-invasive treatment that uses low-wavelength red light or near-infrared light to stimulate cellular function. It’s gaining traction for its potential to support skin health, reduce inflammation, and promote tissue repair.

RLT targets the mitochondria, the energy-producing centers of cells. When exposed to specific wavelengths (typically 600–850 nm), mitochondria absorb the light and produce more ATP (adenosine triphosphate)—the energy currency of the cell. This boost in cellular energy may enhance healing, reduce oxidative stress, and modulate inflammation.[i]

🌟 Potential Benefits

• Skin rejuvenation: May reduce wrinkles, scars, and acne by stimulating collagen and fibroblast production.[ii]
• Wound healing: Shown to accelerate tissue repair and reduce inflammation.[iii]
• Muscle recovery: Used by athletes to reduce soreness and improve performance.[iv]
• Joint pain relief: May help with arthritis and other inflammatory conditions.[v]
• Rheumatoid Arthritis: Decreases inflamed cells.[vi]
• Neurological support: Being explored for cognitive benefits in conditions like dementia.[vii]

Red Light Therapy and Other Health Issues

Beyond its cosmetic applications, RLT has been studied for its effects on mental health, sleep disorders, and wound healing. Research suggests that exposure to red light may improve sleep quality and mood regulation, particularly in individuals with insomnia. Additionally, systematic reviews highlight its potential in stress management and depressive symptom relief.

Red Lighter Therapy Considerations

• Safety: Generally considered safe when used appropriately. It doesn’t emit UV rays and doesn’t burn the skin.
• Devices: Available as panels, masks, wands, or full-body beds. Clinical-grade devices tend to be more powerful than at-home versions.
• Evidence: While promising, more large-scale, peer-reviewed studies are needed to confirm many of the claimed benefits.

How Deep Does Red Light Therapy Penetrate?

The depth of red light penetration depends on its wavelength. Red light therapy typically uses wavelengths between 620 to 700 nanometers, which can penetrate a few millimeters beneath the skin. Studies suggest that red light can penetrate up to 8-10 millimeters, making it effective for treating skin conditions, inflammation, and superficial tissue repair. Near-infrared light, which falls in the 700 to 900 nanometer range, can reach deeper layers, including muscle and tissue.

Red Light Therapy and Cancer

Emerging studies indicate that red light therapy may play a role in cancer treatment, particularly through photodynamic therapy (PDT). PDT utilizes red light to activate photosensitizing agents, destroying cancer cells. Research has explored its effects on skin cancers, esophageal cancer, lung cancer, and cutaneous T-cell lymphoma. A study on melanoma found that red light phototherapy inhibited tumor growth and enhanced immune response. Another investigation into hypoxic tumors—which are notoriously resistant to conventional treatments—demonstrated that red-light-activated compounds could induce cancer cell death even in low-oxygen environments.

Cancers Studied with Red Light Therapy

• Actinic Keratosis[viii]
•  

Natural Compounds That May Enhance Red Light Therapy

Some natural compounds have been studied for their potential to enhance the effects of red light therapy, particularly curcumin, resveratrol, and epigallocatechin gallate (EGCG). These compounds are known for their antioxidant, anti-inflammatory, and anticancer properties, and emerging research suggests they may complement photodynamic therapy (PDT) when exposed to specific wavelengths of light.

• Curcumin: Found in turmeric, curcumin has demonstrated photosensitizing properties, meaning it can become more effective in generating reactive oxygen species (ROS) when exposed to red light. These ROS can help target and destroy cancer cells, making curcumin a potential adjunct in PDT-based cancer therapy.[ix] However, its poor bioavailability remains a challenge, leading researchers to explore nanoparticle formulations that enhance its absorption.[x]
• I often recommend Onco-Adjunct Pathway 2 as a source of highly absorbed curcumin.
• Quercetin:  A natural antihistamine was found to enhance the effectiveness of PDT in Triple Negative Breast Cancer and Melanoma Cancer.[xi]
• I often recommend Onco-Adjunct Pathway 2 as a source of highly absorbed curcumin.
• Resveratrol: This polyphenol, commonly found in red grapes, has been studied for its ability to modulate oxidative stress, apoptosis, and inflammation in cancer therapy. Research suggests that resveratrol may enhance the cytotoxic effects of PDT when combined with light exposure, potentially increasing cancer cell destruction while protecting healthy cells from oxidative damage.
• I often recommend Onco-Adjunct Pathway 4 for a source of highly absorbed resveratrol.
• EGCG (Epigallocatechin Gallate): A key component of green tea, EGCG has antioxidant and anti-cancer properties that may complement light-based cancer treatments. Studies indicate that EGCG can increase the susceptibility of cancer cells to oxidative stress, making them more vulnerable to therapies like red light therapy and PDT.
• I often recommend Onco-Adjunct Pathway 4 for a source of highly absorbed EGCG.

While these compounds show promise, clinical applications are still under investigation, and more studies are needed to determine optimal dosages, wavelengths, and treatment protocols.

Methylene Blue and Red Light Therapy: A Powerful Combination

Enhancing Mitochondrial Function

Methylene blue is a photosensitizer that has been studied for its ability to enhance mitochondrial function when combined with red light therapy. Research suggests that methylene blue can act as an electron donor, supporting the electron transport chain in mitochondria and improving cellular energy production. When exposed to red or near-infrared light, methylene blue stimulates cytochrome oxidase, a key enzyme in mitochondrial respiration, leading to increased ATP production and improved cellular metabolism.

Neuroprotective Benefits

Studies indicate that methylene blue, when combined with red light therapy, may offer neuroprotective benefits. Research has explored its potential in reducing oxidative stress, improving cognitive function, and supporting brain health. A study published in Frontiers in Cellular Neuroscience found that low-dose methylene blue and near-infrared light could protect neurons from degeneration, suggesting potential applications in neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Additionally, methylene blue has been shown to increase neuroplasticity, which may enhance memory and learning.

Applications in Functional Medicine

Beyond neurological benefits, methylene blue and red light therapy have gained attention in functional medicine for their anti-inflammatory, antimicrobial, and antioxidant properties. Some practitioners use this combination to support cellular repair, reduce inflammation, and improve metabolic function. Methylene blue has also been explored for its potential role in mental health treatments, with studies suggesting it may help reduce symptoms of depression and anxiety when paired with photobiomodulation.

While promising, further research is needed to determine optimal dosages, wavelengths, and treatment protocols for different conditions. To explore the latest studies, check out Frontiers in Cellular Neuroscience, Psychology Today, and Spectra Wellness.

Methylene Blue with Red Light Therapy and Cancer

Methylene blue, when combined with red light therapy, has shown promise in photodynamic therapy (PDT) for cancer treatment. As a photosensitizer, methylene blue absorbs red light and generates reactive oxygen species (ROS), which can induce cancer cell apoptosis and disrupt tumor metabolism. A systematic review of preclinical studies found that PDT using methylene blue led to tumor size reduction in multiple cancer types, including colorectal cancer, carcinoma, and melanoma. Additionally, research suggests that methylene blue may enhance the effects of chemotherapy and radiation, making cancer cells more susceptible to treatment. While these findings are promising, further clinical trials are needed to establish optimal dosages and protocols for integrating methylene blue with red light therapy in cancer care.

Potential Health Concerns of Red Light Therapy

Although red light therapy is generally safe, some risks should be considered:

• Overexposure: Prolonged use may lead to temporary skin redness or irritation.
• Eye Safety: Direct exposure to intense red light may harm the eyes, so protective eyewear is recommended during treatment.
• Skin Sensitivity: Individuals with light-sensitive conditions or those taking photosensitizing medications should consult a healthcare provider before starting RLT.
• Burns or Blisters: Using red light therapy for longer than recommended may cause burns or worsen certain skin conditions.

This blog is currently being written. Please check back for more Reference Sources.

PLOS One, Bentham Science, and Springer.

[i] Graeme Ewan Glass, Photobiomodulation: The Clinical Applications of Low-Level Light Therapy, Aesthetic Surgery Journal, Volume 41, Issue 6, June 2021, Pages 723–738, https://doi.org/10.1093/asj/sjab025

[ii] Graeme Ewan Glass, Photobiomodulation: The Clinical Applications of Low-Level Light Therapy, Aesthetic Surgery Journal, Volume 41, Issue 6, June 2021, Pages 723–738, https://doi.org/10.1093/asj/sjab025

[iii] Avci P, Gupta A, Sadasivam M, et al. Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring. Semin Cutan Med Surg. 2013;32(1):41-52. https://pmc.ncbi.nlm.nih.gov/articles/PMC4126803/

[iv] Ferraresi C, Huang YY, Hamblin MR. Photobiomodulation in human muscle tissue: an advantage in sports performance?. J Biophotonics. 2016;9(11-12):1273-1299. doi:10.1002/jbio.201600176  https://pmc.ncbi.nlm.nih.gov/articles/PMC5167494/

[v] Stelian J, Gil I, Habot B, et al. Improvement of pain and disability in elderly patients with degenerative osteoarthritis of the knee treated with narrow-band light therapy. J Am Geriatr Soc. 1992;40(1):23-26. doi:10.1111/j.1532-5415.1992.tb01824.x https://agsjournals.onlinelibrary.wiley.com/doi/abs/10.1111/j.1532-5415.1992.tb01824.x?sid=nlm%3Apubmed

[vi] Neupane J, Ghimire S, Shakya S, Chaudhary L, Shrivastava VP. Effect of light emitting diodes in the photodynamic therapy of rheumatoid arthritis. Photodiagnosis Photodyn Ther. 2010;7(1):44-49. doi:10.1016/j.pdpdt.2009.12.006 https://www.sciencedirect.com/science/article/abs/pii/S1572100009001690?via%3Dihub

[vii] Salehpour F, Mahmoudi J, Kamari F, Sadigh-Eteghad S, Rasta SH, Hamblin MR. Brain Photobiomodulation Therapy: a Narrative Review. Mol Neurobiol. 2018;55(8):6601-6636. doi:10.1007/s12035-017-0852-4 https://pmc.ncbi.nlm.nih.gov/articles/PMC6041198/

[viii] Wang P, Yang Y, Zhao Y, et al. Comparative analysis of recurrence rates: Day-light versus red-light photodynamic therapy in the treatment of actinic keratosis during a five-year follow-up. Photodiagnosis Photodyn Ther. 2025;53:104562. doi:10.1016/j.pdpdt.2025.104562 https://www.sciencedirect.com/science/article/pii/S1572100025000912?via%3Dihub

[ix] Marinho MAG, Marques MDS, Cordeiro MF, de Moraes Vaz Batista Filgueira D, Horn AP. Combination of Curcumin and Photodynamic Therapy Based on the Use of Red Light or Near-Infrared Radiation in Cancer: A Systematic Review. Anticancer Agents Med Chem. 2022;22(17):2985-2997. doi:10.2174/1871520622666220425093657 https://www.eurekaselect.com/article/122835

[x] Niu T, Tian Y, Cai Q, Ren Q, Wei L. Red Light Combined with Blue Light Irradiation Regulates Proliferation and Apoptosis in Skin Keratinocytes in Combination with Low Concentrations of Curcumin. Slominski AT, ed. PLOS ONE. 2015;10(9):e0138754. doi: https://doi.org/10.1371/journal.pone.0138754 

[xi] Hosseinzadeh R, Khorsandi K, Esfahani HS, Habibi M, Hosseinzadeh G. Preparation of cerium-curcumin and cerium-quercetin complexes and their LEDs irradiation assisted anticancer effects on MDA-MB-231 and A375 cancer cell lines. Photodiagnosis Photodyn Ther. 2021;34:102326. doi:10.1016/j.pdpdt.2021.102326