Safety Information & Contraindications

Methylene Blue — Safety & Contraindications | MirthPlus
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Safety Information &
Contraindications

Please read this page carefully before purchasing or using Methylene Blue Drops. Serious drug interactions and medical contraindications apply.

Serotonin Syndrome Risk SSRI / SNRI / MAOI Interaction G6PD Deficiency Pregnancy & Breastfeeding Kidney & Liver Disease Expected Side Effects
IMPORTANT — Read Before Purchasing or Using

Methylene Blue has serious drug interactions, including a life-threatening risk of Serotonin Syndrome when combined with SSRIs, SNRIs, MAOIs, or other serotonergic medications. It is contraindicated in G6PD deficiency, pregnancy, and breastfeeding. Consult your healthcare provider before use.

On This Page

Drug Interactions — Serotonin Syndrome Risk

This is the most critical safety concern with methylene blue. Read carefully.

Methylene blue is a monoamine oxidase A (MAO-A) inhibitor. The FDA has issued a boxed warning: combining methylene blue with serotonergic medications can cause Serotonin Syndrome — a potentially life-threatening condition including agitation, rapid heart rate, high blood pressure, and in severe cases, seizures or death.

SSRIs (Prozac, Zoloft, Lexapro, Celexa, Paxil) Strictly contraindicated. Do not combine under any circumstances without direct physician supervision.
SNRIs (Effexor, Cymbalta, Pristiq) Strictly contraindicated. Same serotonin syndrome risk as SSRIs.
MAOIs (Nardil, Parnate, Marplan) Absolute contraindication. Do not use.
Tricyclic Antidepressants (Amitriptyline, Nortriptyline) Documented serious interaction. Consult your physician before use.
5-HTP, St. John's Wort, Tryptophan These supplements also increase serotonin activity. Combining with methylene blue carries meaningful interaction risk.
Opioid Medications FDA labelling recommends avoiding concomitant use. Consult your healthcare provider.

If you are currently taking any serotonergic medication, do not use this product without speaking to your prescribing physician first. Stopping psychiatric medications to use methylene blue should never be done without medical supervision.

Additional Contraindications & Precautions

The following conditions require you to consult a healthcare provider before using methylene blue.

G6PD Deficiency Contraindicated. Methylene blue can trigger hemolytic anemia in people with glucose-6-phosphate dehydrogenase deficiency — a genetic condition affecting approximately 400 million people globally. G6PD testing is available through your doctor.
Pregnancy & Breastfeeding Do not use. Intra-amniotic exposure has been associated with fetal harm. No adequate safety data exists for breastfeeding.
Kidney Disease Approximately 40% of methylene blue is excreted renally. Renal impairment may extend activity and increase toxicity risk. Use only under physician supervision.
Liver Disease Extensively metabolised in the liver. Hepatic impairment may alter clearance significantly. Physician oversight required.
Under 18 Years of Age Not intended for use by minors. Keep out of reach of children.
Photosensitivity Methylene blue may increase sensitivity to sunlight. Use SPF 30+ sunscreen when spending time outdoors and avoid prolonged UV exposure following use.

Expected Effects at Normal Doses

These are normal and anticipated — not reasons for concern at recommended doses.

Blue or Green Discolouration of Urine & Stool

Normal and expected at all doses. It is the compound cycling through your system as intended — not a sign of harm. Colour intensity varies by dose and individual metabolism.

Blue Tint in Water

The liquid visibly colours water blue. This is expected. Take in a small glass of water or juice — the colour does not affect taste or absorption.

Mild Initial Nausea

Some people notice mild nausea in the first few days, particularly on an empty stomach. Taking with food typically resolves this. It usually dissipates within the first week of use.

Mild Headache in First Few Days

Some users report a mild headache during the initial titration phase. This typically resolves with continued use or a minor dose reduction. Ensure adequate hydration.

Staining of Skin and Clothing

Methylene blue will stain fabric, clothing, countertops, and skin on contact. Handle with care. Skin staining is temporary and fades. Fabric staining is permanent — exercise caution when dispensing.

Stop Use and Seek Medical Help If You Experience:

These symptoms may indicate Serotonin Syndrome or another serious adverse reaction. Discontinue use immediately and contact a healthcare provider or emergency services.

  • Agitation, restlessness, or confusion
  • Rapid or irregular heartbeat
  • Elevated blood pressure or high fever
  • Muscle twitching, stiffness, or loss of coordination
  • Nausea, vomiting, or diarrhoea appearing suddenly
  • Difficulty breathing or chest tightness
MirthPlus Methylene Blue Drops — USP 99.99% grade, blue cobalt glass dropper bottle

Selected by MirthPlus

Methylene Blue Drops

USP Grade · 99.99% Purity · 60mL · 2 fl oz

$39.99

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