Safety First.
Science Second.
Pharmaceutical-grade means complete transparency — including risk. Methylene blue is safe for most healthy adults at 4–30 mg/day. It is not safe for everyone. Here is every contraindication, interaction, and warning, stated plainly.
TL;DR — Safety Summary
Methylene Blue Ultra is safe for most healthy adults at evidence-based doses of 4–30 mg/day. Three situations require you to stop and consult a physician:
- You take antidepressants (SSRIs, SNRIs, MAOIs) — serotonin syndrome risk. This is a hard contraindication.
- You have G6PD deficiency — can trigger hemolytic anemia. Absolute contraindication.
- You are pregnant or breastfeeding — insufficient safety data. Do not use.
Critical Drug Interactions
These interactions are not theoretical — they are documented in published case reports and pharmacology literature. If any of the following apply to you, do not take methylene blue without physician clearance.
Methylene blue inhibits monoamine oxidase. Combining with MAOIs (phenelzine, tranylcypromine, selegiline) creates additive inhibition and dramatically elevates serotonin, dopamine, and norepinephrine. Do not combine under any circumstances.
Concurrent use with fluoxetine, sertraline, escitalopram, venlafaxine, duloxetine, and similar drugs risks serotonin syndrome. Symptoms include hyperthermia, agitation, tremor, rapid heart rate, and — in severe cases — seizures and death.
Methylene blue reduces methemoglobin via NADPH-dependent mechanisms. In G6PD-deficient individuals, this pathway is impaired and methylene blue can paradoxically worsen methemoglobinemia and cause hemolytic anemia. This is a known, well-documented risk.
Methylene blue is a potent, reversible inhibitor of MAO-A. Any serotonergic drug — including triptans, tramadol, lithium, St. John's Wort, and dextromethorphan — carries interaction risk. If you take any neurologically active prescription medication, consult your physician before use.
Side Effects by Dose
Methylene blue has a hormetic dose-response. Side effects are minimal within the therapeutic window and increase sharply above it.
| Dose Range | Classification | Effects |
|---|---|---|
| < 4 mg/day | Sub-therapeutic | Generally no adverse effects — but no meaningful benefit either. Below the threshold for mitochondrial effect. |
| 4–30 mg/day | Therapeutic window | Blue-green urine (normal, harmless). Rare: mild headache or nausea on first use. Well-tolerated in healthy adults without contraindications. |
| > 30 mg/day | Diminishing returns | Increased nausea, headache, and dizziness. Pro-oxidant shift — the mechanism inverts. Benefits plateau and reversal of intended effects begins. Above 2 mg/kg body weight: toxic range (methemoglobinemia risk). |
Who Should Not Take Methylene Blue
Red icons indicate absolute contraindications. Amber icons indicate consult-required situations where individual risk must be assessed.
G6PD Deficiency
Risk of hemolytic anemia. Absolute contraindication.
SSRI / SNRI / MAOI Users
Serotonin syndrome risk. Do not combine with any serotonergic medication.
Pregnancy & Breastfeeding
Insufficient safety data in these populations. Do not use.
Kidney Disease
Methylene blue is renally cleared. Impaired clearance raises plasma levels unpredictably. Consult your physician.
Phenothiazine Hypersensitivity
Methylene blue is a phenothiazine derivative. Known allergy to this class is a contraindication.
Under 18
No clinical data supporting safe use in minors. Not recommended.
Normal vs. Stop Immediately
Normal — Expected Reactions
- ✓Blue-green urine — sign of active excretion
- ✓Blue-green stool at higher doses
- ✓Slight blue tint to saliva if capsule opened
- ✓Vivid or unusual dreams (reported anecdotally)
- ✓Mild temporary energy increase
Stop Immediately — Seek Care
- !High fever, confusion, rapid heart rate (serotonin syndrome)
- !Chest pain or shortness of breath
- !Severe headache or sudden vision changes
- !Severe nausea, vomiting, or abdominal pain
- !Dark brown or chocolate-colored blood (methemoglobinemia)
- !Difficulty breathing or bluish skin coloration unrelated to MB excretion
Medical Disclaimer — Important
Consult your healthcare provider before starting any new supplement, especially if you take prescription medications. The information on this page is for educational purposes only. It does not constitute medical advice and is not a substitute for professional medical consultation, diagnosis, or treatment.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary. This content reflects current scientific literature and does not represent regulatory approval of methylene blue for any indication.
Understand the Science Behind the Formulation
Safe dosing starts with understanding the mechanism. The science page covers the hormetic dose-response curve, electron transport chain bypass, and why most MB products are overdosed.
Pharmaceutical-Grade. Transparently Dosed.
Every batch independently verified. 99.9% USP purity. Formulated within the 4–30 mg evidence-based window.
Launching Q3 2026 — join the founding waitlist.