Methylene Blue: A Guide for People with Cancer

What is Methylene Blue?

Methylene Blue (MB), or methylthionine chloride, is a synthetic compound initially developed as a dye but later found to have various medical applications. It has been used in cancer therapy to treat methemoglobinemia and neurodegenerative diseases and as a photosensitizer.

Where Does Methylene Blue Come From?

Methylene Blue was first synthesized in the late 19th century and has been widely used in medical and scientific research. It is derived from phenothiazine and exists in oxidized (blue) and reduced (colorless) forms.

Anticancer Activity of Methylene Blue

Recent studies suggest that Methylene Blue has potential anticancer properties. Research indicates that Methylene Blue can induce apoptosis (programmed cell death) in prostate cancer cells by upregulating key apoptotic molecules such as Bax and phospho p53. Additionally, Methylene Blue has been explored in terms of its role in cancer imaging and photodynamic therapy.

Oral Use of Methylene Blue for Cancer

Methylene Blue has been investigated for its oral application in cancer treatment, particularly in managing painful oral mucositis caused by chemotherapy and radiation therapy. Some studies suggest that Methylene Blue oral rinses may help alleviate pain and inflammation in cancer patients undergoing treatment.

Methylene Blue Potential Concerns and Side Effects

While Methylene Blue has therapeutic potential, it also carries risks. Some reported side effects include serotonin syndrome when combined with certain medications, discoloration of urine and skin, and potential neurotoxicity. Additionally, Methylene Blue has been associated with hemolysis and methemoglobinemia in high doses. Side effects can include:

• Serotonin Syndrome – Methylene Blue can interact with serotonergic medications, leading to excessive serotonin levels.
• Methemoglobinemia – High doses of Methylene Blue can paradoxically induce methemoglobinemia, reducing oxygen transport in the blood.

• Hemolytic Anemia – Methylene Blue may cause hemolysis, particularly in individuals with a deficiency of glucose-6-phosphate dehydrogenase (G6PD).
• Neurotoxicity – Some studies suggest Methylene Blue may contribute to neurotoxicity at high concentrations.
• Skin, Bowel, and Urine Discoloration – Methylene Blue can cause temporary blue discoloration of the skin, bowel movements (poop), and urine.
• Gastrointestinal Distress – Nausea, vomiting, and abdominal pain have been reported in some cases.
• Hypotension – Methylene Blue may lead to a drop in blood pressure, particularly when administered intravenously.
• Respiratory Distress – Rare cases of respiratory complications have been observed.

Potential Methylene Blue Medication Interactions

Warning: Serotonin Syndrome with Concomitant Use of Serotonergic Drugs and Opioids.

Methylene blue may cause serious or fatal serotonergic syndrome when used in combination with serotonergic drugs.

Avoid using methylene blue with selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), and monoamine oxidase inhibitors.

You can use this Drug Interaction Checker: https://www.drugs.com/drug_interactions.html.

Dosage of Methylene Blue

Methylene Blue (MB) is administered orally or intravenously depending on the condition treated. Studies suggest that Methylene Blue may be an adjunct therapy for cancer-related applications due to its potential oxidative stress modulation and mitochondrial enhancement properties. The dosing strategy varies, but some research indicates that oral Methylene Blue is often taken in small doses ranging from 0.5 mg to 4 mg per kilogram of body weight, with frequency depending on individual tolerance and therapeutic goals. A common adult dose is 1mg/kg of body weight twice daily.

In critical care settings, Methylene Blue has been used in bolus injections followed by continuous infusion, particularly for conditions like vasodilatory shock. However, excessive dosing—above 7 mg/kg—can paradoxically induce methemoglobinemia and hemolytic anemia.

Methylene Blue with Renal (kidney) Impairment Considerations

In people with kidney issues, methylene blue doses can be adjusted:

• Mild to moderate impairment: No dose change is typically needed
• Severe impairment: Use caution, consider dose reduction
• Dialysis patients: Give after dialysis sessions

Monitor renal function blood tests creatine and eGFR and adjust as needed.

Methylene Blue with Hepatic (liver) Impairment Considerations

For people with liver problems, methylene blue dosages can be adjusted:

• Mild impairment: No dose adjustment required
• Moderate to severe impairment: Many practitioners reduce the dose by 50%
• Monitor liver blood AST and ALT tests regularly

Watch for signs of toxicity, such as nausea or confusion.

You should consult a healthcare professional before using Methylene Blue to ensure safe and effective administration.

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Methylene Blue and Red Light Therapy

Light therapy is crucial in activating methylene blue (MB) and enhancing its therapeutic effects. Methylene Blue is a photosensitizer, meaning it absorbs specific wavelengths of light—primarily red and near-infrared (NIR) light—to produce reactive oxygen species (ROS), which can help target cancer cells and pathogens. Studies indicate that Methylene Blue has peak absorption around 635–670 nm, making it particularly effective when combined with low-level laser therapy (LLLT) or photodynamic therapy (PDT).

Research has explored Methylene Blue’s use in antimicrobial applications and cancer treatments, demonstrating that light activation significantly boosts its ability to induce oxidative stress in diseased cells. Additionally, Methylene Blue has been investigated for its role in root canal disinfection, where light activation enhances its penetration and effectiveness against bacterial biofilms. The combination of MB and light therapy continues to be studied for various medical applications, including neuroprotection and wound healing.

Infrared radiation (IR) penetrates the skin and tissues, generating heat at a cellular level. This process increases blood flow, reduces inflammation, and enhances cellular metabolism. IR therapy is commonly divided into three categories:

• Near-Infrared (NIR, 700–1400 nm): Deep tissue penetration, often used for mitochondrial stimulation.
• Mid-Infrared (MIR, 1400–3000 nm): Moderate penetration, beneficial for circulation and detoxification.
• Far-Infrared (FIR, 3000–10000 nm): Surface-level heating, primarily used for relaxation and pain relief.

Most infrared (IR) saunas primarily use far-infrared (FIR) technology. FIR saunas operate at lower temperatures than traditional saunas and penetrate deeper into the body, promoting relaxation and detoxification. However, some saunas incorporate near-infrared (NIR) and mid-infrared (MIR) wavelengths, which may offer additional benefits such as improved circulation, skin rejuvenation, and interaction with methylene blue.

Cancers Studied with Methylene Blue

• Bladder Cancer – Methylene Blue has been explored for its potential role in bladder cancer treatment, particularly in photodynamic therapy.
• Breast Cancer – Studies suggest Methylene Blue may help to image and target breast cancer cells.
• Colorectal Cancer – Research indicates Methylene Blue may enhance photodynamic therapy for colorectal tumors.
• Melanoma – Methylene Blue has been investigated for its ability to induce oxidative stress in melanoma cells.
• Oral Cancer – Methylene Blue enhanced the effectiveness of photodynamic therapy with the chemotherapy drug doxorubicin.
• Prostate Cancer – Methylene Blue has shown promise in inducing apoptosis in prostate cancer cells.

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What This Means for Cancer Treatment

While Methylene Blue shows promise, it's not a standalone cancer cure. Instead, many healthcare practitioners see it as part of a larger treatment toolkit. Perhaps the most exciting potential lies in combining it with existing treatments to improve their effectiveness.

Methylene Blue Medical Disclaimer

The information provided in this article about Methylene Blue and cancer treatment is for educational purposes only. This content is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding your medical condition.

Never disregard professional medical advice or delay seeking it because of something you have read in this article. This information should not be used to diagnose or treat any health condition. If you suspect you have a medical problem, contact your healthcare provider immediately.

Research findings discussed in this article are based on scientific studies but may not be conclusive or applicable to all situations. Treatment outcomes can vary between individuals. Any application of the information provided is at your own risk.

The authors, publishers, and distributors of this content take no responsibility for any liability, loss, or risk, personal or otherwise, which is incurred as a direct or indirect consequence of accessing, using, or applying any of the contents of this article.

References

Priyadarshini Thiruvalluvan Shanthi, Abigail Foes, Gnanasekar Munirathinam. Evaluating the therapeutic effects of methylene blue against prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2958. https://aacrjournals.org/cancerres/article/79/13_Supplement/2958/635047/Abstract-2958-Evaluating-the-therapeutic-effects

Sari-Yavuz, S., Heck-Swain, K.-L., Keller, M., Magunia, H., Feng, Y.-S., Haeberle, H. A., Wied, P., Schlensak, C., Rosenberger, P., and Koeppen, M. (2022). Front. Med. 9:1014276. https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.1094735/full

Horace R, Roldan SP, Roldan CJ. Methylene Blue Oral Rinse: An Effective Alternative for the Treatment of Pain in Oral Mucositis During Head and Neck Cancer Treatment. J Exp Pathol. 2024;5(1):24-30. https://www.scientificarchives.com/article/methylene-blue-oral-rinse-an-effective-alternative-for-the-treatment-of-pain-in-oral-mucositis-during-head-and-neck-cancer-treatment

Roldan, C. J., Chung, M., Feng, L., & Bruera, E. (2021). Methylene Blue for the Treatment of Intractable Pain From Oral Mucositis Related to Cancer Treatment: An Uncontrolled Cohort. Journal of the National Comprehensive Cancer Network, 19(5), 521-527. Retrieved May 9, 2025, from https://doi.org/10.6004/jnccn.2020.7651

Marek Bužga, Evžen Machytka, Eliška Dvořáčková, Zdeněk Švagera, David Stejskal, Jan Máca, Jan Král, Methylene blue: a controversial diagnostic acid and medication?, Toxicology Research, Volume 11, Issue 5, October 2022, Pages 711–717, https://doi.org/10.1093/toxres/tfac050

Seitkazina A, Yang JK, Kim S. Clinical effectiveness and prospects of methylene blue: A systematic review. Precision and Future Medicine. Published online September 29, 2022. doi: https://doi.org/10.23838/pfm.2022.00079  

Giannelli, M., Bani, D. Appropriate laser wavelengths for photodynamic therapy with methylene blue. Lasers Med Sci 33, 1837–1838 (2018). https://doi.org/10.1007/s10103-018-2566-x

Goujani SM, Koopaie M, Safarian FH, Hakimiha N, Younespour S. Comparative analysis of combined methylene blue photodynamic therapy and doxorubicin treatment of oral squamous cell carcinoma cell line: In vitro study on apoptosis. Photodiagnosis Photodyn Ther. 2025;51:104457. doi:10.1016/j.pdpdt.2024.104457 https://www.sciencedirect.com/science/article/pii/S1572100024004939?via%3Dihub

Taldaev A, Terekhov R, Nikitin I, et al. Methylene blue in anticancer photodynamic therapy: systematic review of preclinical studies. Front Pharmacol. 2023;14:1264961. Published 2023 Sep 28. doi:10.3389/fphar.2023.1264961 https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2023.1264961/full

George S, Kishen A. Photophysical, photochemical, and photobiological characterization of methylene blue formulations for light-activated root canal disinfection. Journal of Biomedical Optics. 2007;12(3):034029. doi: https://doi.org/10.1117/1.2745982