Drug & supplement interaction

Methylene Blue + Tetrahydrozoline

Tetrahydrozoline brand name: Tyzine.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated October 2026 · Pair last verified Oct 4, 2026

The bottom line No known interaction

We found no known interaction between Methylene Blue and Tetrahydrozoline in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Methylene Blue and Tetrahydrozoline

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Tetrahydrozoline and Methylene Blue in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Methylene Blue safety at a glance

Methylene Blue overall Use caution It is a real drug with real risks; medical-grade forms need supervision and it should not be self-dosed casually.

Pregnancy Likely Unsafe When prescription methylene blue is used intra-amniotically. When provided during the second trimester, methylene blue has caused fetal intestinal atresia and d... Read the full pregnancy detail

Breastfeeding Possibly Unsafe When prescription methylene blue products are administered to patients who are lactating. Breast-feeding should be discontinued during and for 8 days after trea... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Tetrahydrozoline and Methylene Blue? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Tetrahydrozoline

Interactions in our licensed database are recorded against drug classes, not just single drug names. Tetrahydrozoline is filed under a single classification — topical drugs. Methylene Blue has documented interactions with 2 drug classes — the most serious being anticholinergic drugs (moderate) and serotonergic drugs (moderate) — and none of Tetrahydrozoline’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Methylene Blue Does Interact With Other Medications

Methylene Blue has 315 moderate known drug interactions in our database — Tetrahydrozoline isn’t one of them. If you take anything else, check it against the full list below.

Moderate 315 No known interaction 2,515 (incl. Tetrahydrozoline)

Taking anything else?

Check Another of Your Medications Against Methylene Blue

Covers the 2,830 medications we’ve checked against Methylene Blue. Pick one to open its full report.

What to actually watch for

What Methylene Blue Itself Has Been Linked To

This is not an interaction — nothing below involves Tetrahydrozoline. It is the side-effect record for Methylene Blue on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Methylene Blue, this list is the first place to look. 7 entries are worth acting on rather than waiting out — marked below.

Low magnesium / Low potassium / Anemia Worth acting on Additional detail
“Orally, methylene blue has resulted in dose-dependent reductions in red cell count and hemoglobin, occasionally with anemia, and increases in methemoglobin. The rate of having methemoglobin levels greater than 3.5% during treatment was 1.3%. In another clinical trial, there was a case of megaloblastic anemia requiring vitamin B12 injections following use of methylene blue.”

Methylene Blue · Natural Medicines adverse-effect record, reported in pruritus.
6 sources cited

116414. Wilcock GK, Gauthier S, Frisoni GB, et al. Potential of Low Dose Leuco-Methylthioninium Bis(Hydromethanesulphonate) (LMTM) Monotherapy for Treatment of Mild Alzheimer's Disease: Cohort Analysis as Modified Primary Outcome in a Phase III Clinical Trial. J PubMed

116417. Wischik CM, Staff RT, Wischik DJ, et al. Tau aggregation inhibitor therapy: an exploratory phase 2 study in mild or moderate Alzheimer's disease. J Alzheimers Dis 2015;44(2):705-20. PubMed

116432. Gauthier S, Feldman HH, Schneider LS, et al. Efficacy and safety of tau-aggregation inhibitor therapy in patients with mild or moderate Alzheimer's disease: a randomised, controlled, double-blind, parallel-arm, phase 3 trial. Lancet. 2016;388(10062):2873- PubMed

116423. Naylor GJ, Martin B, Hopwood SE, Watson Y. A two-year double-blind crossover trial of the prophylactic effect of methylene blue in manic-depressive psychosis. Biol Psychiatry 1986;21(10):915-20.

116375. Akazawa M, Wu YH, Liu WM. Allergy-like reactions to methylene blue following laparoscopic chromopertubation: A systematic review of the literature. Eur J Obstet Gynecol Reprod Biol 2019;238:58-62. PubMed

116379. Bilgin H, Ozcan B, Bilgin T. Methemoglobinemia induced by methylene blue pertubation during laparoscopy. Acta Anaesthesiol Scand 1998;42(5):594-5. PubMed
Pain or burning when passing urine / Confusion Worth acting on Additional detail

Recorded for Methylene Blue in the same Natural Medicines adverse-effect record shown under Low magnesium / Low potassium / Anemia above.
A severe skin reaction Worth acting on Additional detail
“When used intravenously, blue skin, necrotic ulcers, papules, and phototoxicity have been reported. Extravasation has occurred following intravenous infusion of methylene blue. In one case, blistering and skin irritation occurred. Intraparenchymally, redness, broken blood vessels, and skin necrosis have been reported rarely.”

Methylene Blue · Natural Medicines adverse-effect record, reported in extravasation.
5 sources cited

116431. US Food and Drug Administration (FDA). PROVAYBLUE® (methylene blue) Prescribing Information. January 2024. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/204630s021lbl.pdf. Accessed July 16, 2025

116362. Chebolu E, Gnirke M, St Francis H, Soghoian S, Su MK. Extravasation with methylthioninium chloride. Clin Toxicol (Phila) 2024;62(11):776-778. PubMed

116458. Khokhar RS, Aqil M, Al-Zahrani T, Gelidan A, Al Khayal K. Novel management of methylene blue extravasation: A case report and review of literature. Saudi J Anaesth. 2015;9(2):211-3. PubMed

116392. Bleicher RJ, Kloth DD, Robinson D, Axelrod P. Inflammatory cutaneous adverse effects of methylene blue dye injection for lymphatic mapping/sentinel lymphadenectomy. J Surg Oncol 2009;99(6):356-60. PubMed

116375. Akazawa M, Wu YH, Liu WM. Allergy-like reactions to methylene blue following laparoscopic chromopertubation: A systematic review of the literature. Eur J Obstet Gynecol Reprod Biol 2019;238:58-62. PubMed
Seizures Worth acting on Additional detail
“Orally, headache, dizziness, weakness, and falls have been reported in clinical research. When used intravenously, headache is common. Other adverse effects include myoclonus and seizure-like symptoms.”

Methylene Blue · Natural Medicines adverse-effect record, reported in tension headache.
6 sources cited

116388. Repici A, Di Stefano AF, Radicioni MM, Jas V, Moro L, Danese S. Methylene blue MMX tablets for chromoendoscopy. Safety tolerability and bioavailability in healthy volunteers. Contemp Clin Trials 2012;33(2):260-7. PubMed

116409. Hamidi-Alamdari D, Hafizi-Lotfabadi S, Bagheri-Moghaddam A, et al. METHYLENE BLUE FOR TREATMENT OF HOSPITALIZED COVID-19 PATIENTS: A RANDOMIZED, CONTROLLED, OPEN-LABEL CLINICAL TRIAL, PHASE 2. Rev Invest Clin 2021;73(3):190-198. PubMed

116414. Wilcock GK, Gauthier S, Frisoni GB, et al. Potential of Low Dose Leuco-Methylthioninium Bis(Hydromethanesulphonate) (LMTM) Monotherapy for Treatment of Mild Alzheimer's Disease: Cohort Analysis as Modified Primary Outcome in a Phase III Clinical Trial. J PubMed

116417. Wischik CM, Staff RT, Wischik DJ, et al. Tau aggregation inhibitor therapy: an exploratory phase 2 study in mild or moderate Alzheimer's disease. J Alzheimers Dis 2015;44(2):705-20. PubMed

116419. Alda M, McKinnon M, Blagdon R, et al. Methylene blue treatment for residual symptoms of bipolar disorder: randomised crossover study. Br J Psychiatry 2017;210(1):54-60. PubMed

116424. Telch MJ, Bruchey AK, Rosenfield D, et al. Effects of post-session administration of methylene blue on fear extinction and contextual memory in adults with claustrophobia. Am J Psychiatry 2014;171(10):1091-8. PubMed
Raised blood pressure Worth acting on Additional detail
“When used intravenously, hypertension, palpitations, and tachycardia have been reported.”

Methylene Blue · Natural Medicines adverse-effect record, reported in irregular heartbeat.
1 source cited

116431. US Food and Drug Administration (FDA). PROVAYBLUE® (methylene blue) Prescribing Information. January 2024. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/204630s021lbl.pdf. Accessed July 16, 2025
A severe allergic reaction Worth acting on Additional detail
“An anaphylactic-like reaction to methylene blue, requiring epinephrine, has been reported in an infant during surgery . However, skin-prick testing was negative. In a case report, a 44-year-old female developed a systemic allergic reaction with acute pulmonary edema following subcutaneous injection with methylene blue.”

Methylene Blue · Natural Medicines adverse-effect record, reported in pregnancy-related edema.
3 sources cited

116391. Giladi AM, Kasten SJ. Anaphylactic-like reaction to methylene blue: case report and review of perioperative hypersensitivity reactions. Plast Reconstr Surg 2012;130(1):98e-105e. PubMed

116395. Teknos D, Ramcharan A, Oluwole SF. Pulmonary edema associated with methylene blue dye administration during sentinel lymph node biopsy. J Natl Med Assoc 2008;100(12):1483-4. PubMed

116375. Akazawa M, Wu YH, Liu WM. Allergy-like reactions to methylene blue following laparoscopic chromopertubation: A systematic review of the literature. Eur J Obstet Gynecol Reprod Biol 2019;238:58-62. PubMed
Hives Worth acting on Additional detail

Recorded for Methylene Blue in the same Natural Medicines adverse-effect record shown under A severe allergic reaction above.

Showing the 10 most notable of 24 recorded effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

Everything above comes from the Natural Medicines adverse-effect record for Methylene Blue — expand a row for the licensed statement it rests on. We haven’t matched Tetrahydrozoline to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Tetrahydrozoline.

Special populations

Methylene Blue in Pregnancy & Breastfeeding

Pregnancy Likely Unsafe

When prescription methylene blue is used intra-amniotically. When provided during the second trimester, methylene blue has caused fetal intestinal atresia and death. When used close to term, adverse effects have been reported in the newborn including hemolytic anemia, hyperbilirubinemia, methemoglobinemia, photosensitivity, and respiratory distress. Phototherapy and blood exchange transfusion have been required.

Lactation Possibly Unsafe

When prescription methylene blue products are administered to patients who are lactating. Breast-feeding should be discontinued during and for 8 days after treatment.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Methylene Blue or Tetrahydrozoline

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Methylene Blue or Tetrahydrozoline, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Tetrahydrozoline

This page covers Methylene Blue only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tetrahydrozoline page lists 3 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Dimethylsulfoxide (dmso) (moderate), Turpentine Oil (moderate) and Alchemilla (minor).

By severity: 2 moderate · 1 minor.

From our pharmacist’s overview on the Tetrahydrozoline page

“Tetrahydrozoline (Tyzine) narrows blood vessels in the nose to relieve congestion, and the supplement list tied to it is short: just three ingredients, none rated major. That puts this in comfortable territory for most people, provided you know what the two moderate entries actually do.”

Reviewed by 2 · Jul 18, 2026

Open the Tetrahydrozoline interaction page

How much people look this up

Where Methylene Blue and Tetrahydrozoline Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Methylene Blue

Top half

#640 of 1,452 supplements looked up here in the last 7 days

29 days ago today

Medication Tetrahydrozoline

Top half

#1,106 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?

Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Methylene Blue reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Methylene Blue and Tetrahydrozoline records this page draws on were last updated October 6, 2026.
What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.

Data structure & sourcing designed and verified by Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Methylene Blue

What is Methylene Blue?

Methemoglobinemia (a blood disorder)
Claimed energy or mental focus support
Anti-aging or longevity claims
Antimicrobial or antimalarial uses (historical)
Dye for medical and lab procedures

Methylene blue is a synthetic dye that is an FDA-approved prescription medicine for a rare blood disorder called methemoglobinemia, and it is also used as a diagnostic dye. Its popular use as a supplement for energy, brain health, or anti-aging is not well supported by solid human evidence, and it can cause serious side effects. Talk to a pharmacist or doctor before using it, and never take non-pharmaceutical or industrial-grade products.

Synthetic chemical compound (not derived from a plant) · Prescription injection, oral tablets, and compounded liquid or capsule supplements

An interaction check asks whether these two react with each other — it does not ask whether Methylene Blue is a good idea for someone in your situation. Here is what our Methylene Blue record says about it on its own.

Methylene Blue: dosing

There is no established safe supplement dose of methylene blue. In hospitals, medical doses are carefully calculated by weight and given by trained staff, which is very different from taking it on your own.Supplement products vary widely in strength and quality, and some sold online are not intended for people. If you are considering methylene blue, do not guess at a dose. They can review your health conditions and all your medicines to help you decide whether it is safe for you.

From our Methylene Blue monograph — the full record covers uses, side effects and every documented interaction.

Read the full Methylene Blue monograph & all interactions

Keep checking

Other Drugs & Methylene Blue

Browse every other medication we’ve checked against Methylene Blue — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major

315Moderate

0Minor

2,514No known interaction

315 Moderate 2,514 No interaction

Moderate

315 interactions

Showing 60 of 315 moderate interactions — see all 315 on the Methylene Blue page.

No interaction 2,514 drugs checked — show the list

We also checked Methylene Blue against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,514 medications checked with no known interaction — see the full Methylene Blue list.

See the full Methylene Blue interactions page

See every supplement checked against Tetrahydrozoline, ranked by severity

Evidence & sources

Methylene Blue References

The 60 references that drive our Methylene Blue monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

Chebolu E, Gnirke M, St Francis H, Soghoian S, Su MK. Extravasation with methylthioninium chloride. Clin Toxicol (Phila) 2024;62(11):776-778. PubMed
Walter-Sack I, Rengelshausen J, Oberwittler H, et al. High absolute bioavailability of methylene blue given as an aqueous oral formulation. Eur J Clin Pharmacol. 2009;65(2):179-89. PubMed
Akazawa M, Wu YH, Liu WM. Allergy-like reactions to methylene blue following laparoscopic chromopertubation: A systematic review of the literature. Eur J Obstet Gynecol Reprod Biol 2019;238:58-62. PubMed
Aldeghaither S, Deschênes PJF, Samoukovic G. Anticholinergic Toxidrome as a Possible Explanation for Methylene Blue Toxicity. Am J Case Rep 2023;24:e941453. PubMed
Liao YP, Hung DZ, Yang DY. Hemolytic anemia after methylene blue therapy for aniline-induced methemoglobinemia. Vet Hum Toxicol 2002;44(1):19-21.
Bilgin H, Ozcan B, Bilgin T. Methemoglobinemia induced by methylene blue pertubation during laparoscopy. Acta Anaesthesiol Scand 1998;42(5):594-5. PubMed
Kirlangitis JJ, Middaugh RE, Zablocki A, Rodriquez F. False indication of arterial oxygen desaturation and methemoglobinemia following injection of methylene blue in urological surgery. Mil Med 1990;155(6):260-2. DOI
Porat R, Gilbert S, Magilner D. Methylene blue-induced phototoxicity: an unrecognized complication. Pediatrics 1996;97(5):717-21. DOI
Honoré PJ, Deianova N, Loret G, Hemelsoet D. An easily overlooked cause of toxic encephalopathy: methylene blue in a patient on an SSRI. Acta Neurol Belg 2018;118(1):121-122. PubMed
McRobb CM, Holt DW. Methylene blue-induced methemoglobinemia during cardiopulmonary bypass? A case report and literature review. J Extra Corpor Technol 2008;40(3):206-14. DOI
Donaldson CJ, Sequeira Campos M, El-Sayed M. Inadvertent foetal exposure to methylene blue in the first trimester. J Obstet Gynaecol 2020;40(4):573-574. PubMed
Vanhinsbergh L, Uthaya S, Bain BJ. Methylene blue-induced Heinz body hemolytic anemia in a premature neonate. Am J Hematol 2018;93(5):716-717.
Repici A, Di Stefano AF, Radicioni MM, Jas V, Moro L, Danese S. Methylene blue MMX tablets for chromoendoscopy. Safety tolerability and bioavailability in healthy volunteers. Contemp Clin Trials 2012;33(2):260-7. PubMed
Lee DC, Valente JH. Methylene blue dye-induced knee effusion. Am J Emerg Med 1999;17(7):739-40. PubMed
Albert M, Lessin MS, Gilchrist BF. Methylene blue: dangerous dye for neonates. J Pediatr Surg 2003;38(8):1244-5. PubMed
Giladi AM, Kasten SJ. Anaphylactic-like reaction to methylene blue: case report and review of perioperative hypersensitivity reactions. Plast Reconstr Surg 2012;130(1):98e-105e. PubMed
Bleicher RJ, Kloth DD, Robinson D, Axelrod P. Inflammatory cutaneous adverse effects of methylene blue dye injection for lymphatic mapping/sentinel lymphadenectomy. J Surg Oncol 2009;99(6):356-60. PubMed
George M. Methylene-blue-induced hyperbilirubinemia and phototoxicity in a neonate. Clin Pediatr (Phila) 2000;39(11):659-61.
Lam CW, Wong SY. A case of green urine due to a traditional Chinese medicine containing methylene blue. N Z Med J 2010;123(1312):71-6.
Teknos D, Ramcharan A, Oluwole SF. Pulmonary edema associated with methylene blue dye administration during sentinel lymph node biopsy. J Natl Med Assoc 2008;100(12):1483-4. PubMed
Huang WH, Li MJ. Postoperative Serotonin Syndrome Following Administration of Preoperative Intrapulmonary Methylene Blue and Intraoperative Granisetron: A Case Report. Am J Case Rep 2022;23:e936317. PubMed
Basta MN. Postoperative Serotonin Syndrome Following Methylene Blue Administration for Vasoplegia After Cardiac Surgery: A Case Report and Review of the Literature. Semin Cardiothorac Vasc Anesth 2021;25(1):51-56. PubMed
Gilbert B, Akamune IE. A Case of Serotonin Syndrome Caused by the Concomitant Utilization of Methylene Blue and Venlafaxine in an Oncological Patient. J Pharm Pract 2020;33(5):705-707. PubMed
Hashmi AT, Gupta SS, Shankar S, Seneviratne C, Yoon TS, Kupfer Y. Life-Threatening Serotonin Syndrome Due to Methylene Blue-Citalopram Interaction. Am J Ther 2019;26(6):e740-e741. PubMed
Pelletier JP, Transue S, Snyder EL. Pathogen inactivation techniques. Best Pract Res Clin Haematol. 2006;19(1):205-42. PubMed
Francescangeli J, Vaida S, Bonavia AS. Perioperative Diagnosis and Treatment of Serotonin Syndrome Following Administration of Methylene Blue. Am J Case Rep 2016;17:347-51. PubMed
Hencken L, To L, Ly N, Morgan JA. Serotonin Syndrome Following Methylene Blue Administration for Vasoplegic Syndrome. J Card Surg 2016;31(4):208-10. PubMed
Wolvetang T, Janse R, Ter Horst M. Serotonin Syndrome After Methylene Blue Administration During Cardiac Surgery: A Case Report and Review. J Cardiothorac Vasc Anesth 2016;30(4):1042-5. PubMed
Smith CJ, Wang D, Sgambelluri A, Kramer RS, Gagnon DJ. Serotonin syndrome following methylene blue administration during cardiothoracic surgery. J Pharm Pract 2015;28(2):207-11. PubMed
Top WM, Gillman PK, de Langen CJ, Kooy A. Fatal methylene blue associated serotonin toxicity. Neth J Med 2014;72(3):179-81.
McDonnell AM, Rybak I, Wadleigh M, Fisher DC. Suspected serotonin syndrome in a patient being treated with methylene blue for ifosfamide encephalopathy. J Oncol Pharm Pract 2012;18(4):436-9. PubMed
Grubb KJ, Kennedy JL, Bergin JD, Groves DS, Kern JA. The role of methylene blue in serotonin syndrome following cardiac transplantation: a case report and review of the literature. J Thorac Cardiovasc Surg 2012;144(5):e113-6. PubMed
Sanei ZS, Shahrahmani F, Khaleghi Manesh B, et al. Methylene blue for COVID-19 ARDS: insights from a randomized Clinical Trial. Naunyn Schmiedebergs Arch Pharmacol 2025;398(2):1915-1924. PubMed
Hamidi-Alamdari D, Hafizi-Lotfabadi S, Bagheri-Moghaddam A, et al. METHYLENE BLUE FOR TREATMENT OF HOSPITALIZED COVID-19 PATIENTS: A RANDOMIZED, CONTROLLED, OPEN-LABEL CLINICAL TRIAL, PHASE 2. Rev Invest Clin 2021;73(3):190-198. PubMed
Alamdari DH, Moghaddam AB, Amini S, et al. Application of methylene blue -vitamin C -N-acetyl cysteine for treatment of critically ill COVID-19 patients, report of a phase-I clinical trial. Eur J Pharmacol 2020;885:173494. PubMed
Guo X, Ding W, Liu L, Yang S. Intradiscal Methylene Blue Injection for Discogenic Low Back Pain: A Meta-Analysis. Pain Pract 2019;19(1):118-129. PubMed
Deng M, Huang H, Ma YG, Zhou Y, Chen Q, Xie P. Intradiskal Injection of Methylene Blue for Discogenic Back Pain: A Meta-Analysis of Randomized Controlled Trials. J Neurol Surg A Cent Eur Neurosurg 2021;82(2):161-165. PubMed
Farrokhi MR, Lotfi M, Masoudi MS, Gholami M. Effects of methylene blue on postoperative low-back pain and functional outcomes after lumbar open discectomy: a triple-blind, randomized placebo-controlled trial. J Neurosurg Spine 2016;24(1):7-15. View abstra PubMed
Wilcock GK, Gauthier S, Frisoni GB, et al. Potential of Low Dose Leuco-Methylthioninium Bis(Hydromethanesulphonate) (LMTM) Monotherapy for Treatment of Mild Alzheimer's Disease: Cohort Analysis as Modified Primary Outcome in a Phase III Clinical Trial. J PubMed
Rodriguez P, Zhou W, Barrett DW, et al. Multimodal Randomized Functional MR Imaging of the Effects of Methylene Blue in the Human Brain. Radiology 2016;281(2):516-526. PubMed
Rodriguez P, Singh AP, Malloy KE, et al. Methylene blue modulates functional connectivity in the human brain. Brain Imaging Behav 2017;11(3):640-648. PubMed
Wischik CM, Staff RT, Wischik DJ, et al. Tau aggregation inhibitor therapy: an exploratory phase 2 study in mild or moderate Alzheimer's disease. J Alzheimers Dis 2015;44(2):705-20. PubMed
Baddeley TC, McCaffrey J, Storey JM, et al. Complex disposition of methylthioninium redox forms determines efficacy in tau aggregation inhibitor therapy for Alzheimer's disease. J Pharmacol Exp Ther 2015;352(1):110-8. PubMed
Alda M, McKinnon M, Blagdon R, et al. Methylene blue treatment for residual symptoms of bipolar disorder: randomised crossover study. Br J Psychiatry 2017;210(1):54-60. PubMed
Zhang Z, Zhu Z, Liu H, Chen J, Jin C, Zhang X. A Prospective, Randomized, Controlled Trial of Methylene Blue Injection for Costal Cartilage Harvest Postoperative Analgesia. Aesthet Surg J 2025;45(2):NP65-NP70. PubMed
Soliman M, Salah M, Fadel M, Nasr M, El-Azab H. Contrasting the efficacy of pulsed dye laser and photodynamic methylene blue nanoemulgel therapy in treating acne vulgaris. Arch Dermatol Res 2021;313(3):173-180. PubMed
Alves RO, Urzedo LOR, de Toledo PTA. Antimicrobial Photodynamic Therapy in Onychomycosis Management: A Systematic Review of Clinical Trials. Photodiagnosis Photodyn Ther. 2025:104640. PubMed
Naylor GJ, Martin B, Hopwood SE, Watson Y. A two-year double-blind crossover trial of the prophylactic effect of methylene blue in manic-depressive psychosis. Biol Psychiatry 1986;21(10):915-20.
Telch MJ, Bruchey AK, Rosenfield D, et al. Effects of post-session administration of methylene blue on fear extinction and contextual memory in adults with claustrophobia. Am J Psychiatry 2014;171(10):1091-8. PubMed
Jia W, Li Q, Ni J, Zhang Y, Wu L, Xu L. Efficacy and safety of methylene blue injection for intractable idiopathic pruritus ani: a single-arm metaanalysis and systematic review. Tech Coloproctol 2023;27(10):813-825. PubMed
Xue H, Thaivalappil A, Cao K. The Potentials of Methylene Blue as an Anti-Aging Drug. Cells 2021;10(12):3379. PubMed
Wickramasinghe D, Wickramasinghe N, Samarasekera N, Warusavitarne J. The effect of local infiltration of methylene blue on posthemorrhoidectomy pain: A systematic review and meta-analysis. Curr Probl Surg 2025;67:101752. PubMed
Gureev AP, Sadovnikova IS, Popov VN. Molecular Mechanisms of the Neuroprotective Effect of Methylene Blue. Biochemistry (Mosc) 2022;87(9):940-956. PubMed
Isaev NK, Genrikhs EE, Stelmashook EV. Methylene blue and its potential in the treatment of traumatic brain injury, brain ischemia, and Alzheimer's disease. Rev Neurosci 2024;35(5):585-595. PubMed
Tariq B, Simon SR, Pilz W, Maxim A, Kremer B, Baijens LWJ. Evaluating the safety of oral methylene blue during swallowing assessment: a systematic review. Eur Arch Otorhinolaryngol 2021;278(9):3155-3169. PubMed
US Food and Drug Administration (FDA). PROVAYBLUE® (methylene blue) Prescribing Information. January 2024. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/204630s021lbl.pdf. Accessed July 16, 2025
Gauthier S, Feldman HH, Schneider LS, et al. Efficacy and safety of tau-aggregation inhibitor therapy in patients with mild or moderate Alzheimer's disease: a randomised, controlled, double-blind, parallel-arm, phase 3 trial. Lancet. 2016;388(10062):2873- PubMed
Lu G, Nagbanshi M, Goldau N, et al. Efficacy and safety of methylene blue in the treatment of malaria: a systematic review. BMC Med. 2018;16(1):59. PubMed
Pelgrims J, De Vos F, Van den Brande J, et al. Methylene blue in the treatment and prevention of ifosfamide-induced encephalopathy: report of 12 cases and a review of the literature. Br J Cancer. 2000;82(2):291-4. PubMed
Khokhar RS, Aqil M, Al-Zahrani T, Gelidan A, Al Khayal K. Novel management of methylene blue extravasation: A case report and review of literature. Saudi J Anaesth. 2015;9(2):211-3. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Methylene Blue and Tetrahydrozoline Together: Common Questions

Is it safe to take Methylene Blue with Tetrahydrozoline?

We do not list a known interaction between Methylene Blue and Tetrahydrozoline. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.

How was the Methylene Blue and Tetrahydrozoline combination checked?

Interactions in our licensed database are recorded against drug classes. Tetrahydrozoline is filed under 1 classification, and Methylene Blue has documented interactions with 2 drug classes — none of Tetrahydrozoline's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.

Does Methylene Blue interact with any other medications?

Yes. Methylene Blue has 315 documented drug interactions in our database — Tetrahydrozoline is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

Does Tetrahydrozoline interact with any supplements?

Yes. Tetrahydrozoline has documented interactions with 3 supplements in our database — Methylene Blue is not one of them. The Tetrahydrozoline interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.