Drug & supplement interaction

Methylene Blue + Cabotegravir Sodium

Cabotegravir Sodium brand name: Vocabria.

No Known Interaction

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

The bottom line No known interaction

We found no known interaction between Methylene Blue and Cabotegravir Sodium 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Methylene Blue and Cabotegravir Sodium

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 Cabotegravir Sodium 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 PREGNANCY: Likely Unsafe when prescription methylene blue is used intra-amniotically. When provided during the second trimester, methylene blue has caused fetal... Read the full pregnancy detail

Breastfeeding Possibly Unsafe LACTATION: Possibly Unsafe when prescription methylene blue products are administered to patients who are lactating. Breast-feeding should be discontinued durin... 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 Cabotegravir Sodium and Methylene Blue? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Cabotegravir Sodium

Interactions in our licensed database are recorded against drug classes, not just single drug names. Cabotegravir Sodium is filed under 2 classifications — glucuronidated drugs, oral drugs. Methylene Blue has documented interactions with 2 drug classes — the most serious being anticholinergic drugs (moderate) and serotonergic drugs (moderate) — and none of Cabotegravir Sodium’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 — Cabotegravir Sodium 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. Cabotegravir Sodium)

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

No Interaction Found — But Data Suggests Methylene Blue and Cabotegravir Sodium May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

An allergic reaction Worth acting on Additional detail

Methylene Blue

“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 immunologic.

Cabotegravir Sodium

Listed in the ADVERSE REACTIONS section of the FDA label for Cabotegravir Sodium. Read the label on DailyMed ›
Bloating or gas Additional detail

Methylene Blue

“Orally, gastrointestinal adverse effects are common, including abdominal pain, diarrhea, fecal discoloration, nausea, and vomiting. Blue feces, saliva, and vomitus have also occurred rarely when methylene blue is given for chromopertubation during laparoscopy. When used intravenously, the most common adverse events include diarrhea and nausea.”

Methylene Blue · Natural Medicines adverse-effect record, reported in gastrointestinal.

Cabotegravir Sodium

Listed in the ADVERSE REACTIONS section of the FDA label for Cabotegravir Sodium. Read the label on DailyMed ›
Muscle pain Additional detail

Methylene Blue

“When used intravenously, myalgia has been reported. In a case report, methylene blue instilled into the joint was thought to be the cause of knee effusion in a 13-year old male.”

Methylene Blue · Natural Medicines adverse-effect record, reported in musculoskeletal.

Cabotegravir Sodium

Listed in the ADVERSE REACTIONS section of the FDA label for Cabotegravir Sodium. Read the label on DailyMed ›
Stomach pain / Diarrhea / Vomiting / Nausea Additional detail

Methylene Blue

“Orally: Abdominal pain, blue/green urine, diarrhea, dysuria, fecal discoloration, headache, nausea, and vomiting. Intravenous: Blue skin, diarrhea, dysuria, headache, hypokalemia, hypomagnesemia, myoclonus, and nausea.”

Methylene Blue · Natural Medicines adverse-effect record, reported in general.

Cabotegravir Sodium

Listed in the ADVERSE REACTIONS section of the FDA label for Cabotegravir Sodium. Read the label on DailyMed ›
Dizziness Additional detail

Methylene Blue

“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 neurologic/cns.

Cabotegravir Sodium

Listed in the ADVERSE REACTIONS section of the FDA label for Cabotegravir Sodium. Read the label on DailyMed ›
Headache Additional detail

Methylene Blue

Recorded for Methylene Blue in the same Natural Medicines adverse-effect record shown under Stomach pain / Diarrhea / Vomiting / Nausea above.

Cabotegravir Sodium

Listed in the ADVERSE REACTIONS section of the FDA label for Cabotegravir Sodium. Read the label on DailyMed ›

Reported for Methylene Blue but not commonly for Cabotegravir Sodium: confusion, sore throat, yellowing of the skin or eyes and a severe allergic reaction.

Effects for Cabotegravir Sodium come from the ADVERSE REACTIONS section of its FDA label; effects for Methylene Blue come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 15,229 voluntary FDA FAERS reports for Cabotegravir Sodium that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Methylene Blue in Pregnancy & Breastfeeding

Adults Likely Safe

Likely Safe when prescription methylene blue products are used intravenously and appropriately, short-term. Methylene blue is available as an FDA-approved prescription product. There is insufficient reliable information available about the safety of any form of supplemental or non-prescription methylene blue product.

Children Likely Safe

CHILDREN: Likely Safe when prescription methylene blue products are used intravenously and appropriately, short-term. Methylene blue is available as an FDA-approved prescription product. Cases of hemolytic anemia, hyperbilirubinemia, and acute renal failure have occurred rarely in neonates. CHILDREN: There is insufficient reliable information available about the safety of any form of supplemental or non-prescription methylene blue product.

Pregnancy Likely Unsafe

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. PREGNANCY: There is insufficient reliable information available about the safety of methylene blue given by intrauterine injection during the first trimester. Inadvertent exposure in 4 case reports has not resulted in adverse effects. PREGNANCY: There is insufficient reliable information available about the safety of oral supplemental or non-prescription methylene blue products. However, fetal toxicity, including fetal loss, malformations, and reduced fetal weight, has been observed in animal studies at high doses.

Lactation Possibly Unsafe

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. LACTATION: There is insufficient reliable information available about the safety of oral supplemental or non-prescription methylene blue products.

Safety ratings from the Natural Medicines database. If you are pregnant or nursing, review any supplement with your OB or pharmacist first.

Overlapping uses

What Cabotegravir Sodium Is Prescribed For, and What Methylene Blue Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Cabotegravir Sodium is a prescription medicine with approved uses on its FDA label. Methylene Blue is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Cabotegravir Sodium is prescribed for: Vocabria tablets are used with rilpivirine (Edurant) for short-term treatment of HIV-1 infection in adults and adolescents 12 and older who weigh at least 35 kg and whose virus is already suppressed. They can also be used as an oral lead-in before, or as a bridge between, CABENUVA injections. Apretude (cabotegravir extended-release injection) is used for HIV-1 PrEP, to reduce the risk of getting HIV-1 infection. Vocabria tablets may be used as an optional oral lead-in before Apretude.

Methylene Blue has been studied for:

Cancer studied, not established Methylene Blue has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

Methylene Blue for cancer

Although there is interest in using oral methylene blue for cancer treatment, there is insufficient reliable information about the clinical effects of methylene blue for this purpose.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Cabotegravir Sodium on your own; if you are taking Methylene Blue for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Methylene Blue or Cabotegravir Sodium

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 Cabotegravir Sodium, 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 Cabotegravir Sodium

This page covers Methylene Blue only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cabotegravir Sodium page lists 29 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Breadfruit (moderate), Brussels Sprout (moderate), Cabbage (moderate) and Calcium D-glucarate (moderate).

By severity: 1 major · 18 moderate · 10 minor.

From our pharmacist’s overview on the Cabotegravir Sodium page

“Cabotegravir (Vocabria) is an HIV medicine, and keeping its blood level steady is what keeps the virus suppressed, so I read this list of 29 interacting supplements with genuine concern. The one major entry is activated charcoal, a popular detox remedy that soaks up drugs in the gut and cuts how much reaches you.”

Reviewed by 2 · Jul 18, 2026

Open the Cabotegravir Sodium interaction page

How much people look this up

Where Methylene Blue and Cabotegravir Sodium 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

Steady interest

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

29 days ago today

Medication Cabotegravir Sodium

Top half

#711 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 Cabotegravir Sodium records this page draws on were last updated July 16, 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

Medication

About Cabotegravir

What Is Cabotegravir Used For?

Brand name: Vocabria

Vocabria tablets are used with rilpivirine (Edurant) for short-term treatment of HIV-1 infection in adults and adolescents 12 and older who weigh at least 35 kg and whose virus is already suppressed. They can also be used as an oral lead-in before, or as a bridge between, CABENUVA injections.

Apretude (cabotegravir extended-release injection) is used for HIV-1 PrEP, to reduce the risk of getting HIV-1 infection. Vocabria tablets may be used as an optional oral lead-in before Apretude.

See full Cabotegravir drug information

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 Cabotegravir Sodium, 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 Cabotegravir Sodium Together: Common Questions

Is it safe to take Methylene Blue with Cabotegravir Sodium?

We do not list a known interaction between Methylene Blue and Cabotegravir Sodium. 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.

Do Methylene Blue and Cabotegravir Sodium have any of the same side effects?

Yes — our sources link each of them separately to 9 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.

Are Methylene Blue and Cabotegravir Sodium used for the same thing?

They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Methylene Blue in each. That is a conversation for your prescriber, especially if Cabotegravir Sodium is being adjusted to a target.

How was the Methylene Blue and Cabotegravir Sodium combination checked?

Interactions in our licensed database are recorded against drug classes. Cabotegravir Sodium is filed under 2 classifications, and Methylene Blue has documented interactions with 2 drug classes — none of Cabotegravir Sodium'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 — Cabotegravir Sodium 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 Cabotegravir Sodium interact with any supplements?

Yes. Cabotegravir Sodium has documented interactions with 29 supplements in our database — Methylene Blue is not one of them. The Cabotegravir Sodium 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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Methylene Blue monograph Uses, safety profile, and every drug interaction in one place Cabotegravir drug information The full plain-English guide to this medication Cabotegravir Sodium supplement interactions Every supplement checked against Cabotegravir Sodium, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 60 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

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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.