Methylene blue and antidepressants: why this combination is off the table

Methylene blue is an MAO inhibitor

Monoamine oxidase A is one of the main enzymes that clears serotonin from the brain and body. Methylene blue inhibits it. That makes methylene blue behave, in this one respect, like the older MAO inhibitor antidepressants that come with strict medicine and food rules.

MedlinePlus lists methylene blue alongside phenelzine, isocarboxazid and linezolid as an MAO inhibitor in its drug interaction warnings for common antidepressants. The FDA-approved intravenous product, ProvayBlue, carries a boxed warning that it may cause serious or fatal serotonin syndrome when used with serotonergic drugs and opioids.

What the FDA found

In 2011, the FDA issued a Drug Safety Communication after reports of serious central nervous system reactions, including serotonin syndrome, in people given methylene blue while taking serotonergic psychiatric medicines. Most reported cases involved intravenous doses of 1 to 8 mg/kg during surgery. The FDA said it is not known whether the risk applies at lower intravenous doses or with other routes such as oral use.

That uncertainty is exactly why caution is the sensible default. Oral methylene blue products marketed for wellness have not been studied for this interaction at the doses people take, and absence of data is not proof of safety.

Medicines that rule out methylene blue

The FDA named specific antidepressants in its communication, and MedlinePlus and the product label point to a wider group of serotonergic drugs. If you take any of the following, now or recently, methylene blue is not appropriate:

• SSRIs, such as sertraline, fluoxetine, paroxetine, citalopram and escitalopram
• SNRIs, such as venlafaxine, desvenlafaxine and duloxetine
• Clomipramine and other tricyclic antidepressants
• MAO inhibitor antidepressants and selegiline
• Other antidepressants and related drugs the FDA flagged, including bupropion, buspirone, mirtazapine and trazodone
• Triptans for migraine
• Certain opioids, such as tramadol, meperidine and fentanyl
• Dextromethorphan cough medicines, linezolid, lithium and St. John's wort

What serotonin syndrome looks like

MedlinePlus describes symptoms that can appear within minutes to hours: agitation or restlessness, fast heartbeat, high or swinging blood pressure, high temperature, sweating, diarrhea, nausea, muscle twitching, overactive reflexes, poor coordination and hallucinations. It can worsen quickly and can be fatal without treatment.

If you develop these symptoms after taking methylene blue with any other medicine, seek emergency care immediately.

Why stopping your antidepressant is not the answer

Some people ask whether they can pause an SSRI to try methylene blue. We do not recommend this. Antidepressants treat real conditions, and stopping abruptly can cause withdrawal symptoms or a return of depression or anxiety. Methylene blue is an experimental wellness option; your mental health treatment is not something to trade for it.

Timing is another problem. Many serotonergic drugs take days to weeks to clear. For fluoxetine, MedlinePlus advises waiting at least 5 weeks after stopping before starting an MAO inhibitor, because the drug and its active breakdown product linger. Any change to an antidepressant should be made only with the clinician who prescribes it.

Occasional use still counts

The interaction does not depend on taking a medicine every day. A single triptan for a migraine, an over-the-counter cough syrup with dextromethorphan, or a short course of tramadol after a dental procedure can be enough to create risk while methylene blue is in your system. Tell every prescriber, dentist and pharmacist that you take methylene blue.

If a new medicine is started later

Your medicine list can change after you start methylene blue. A new prescription for depression, anxiety, migraine, pain or a urinary infection might be serotonergic or interact in other ways. Stop methylene blue and contact your HealifyMD clinician before taking the new medicine, and make sure the prescriber knows you have been using it. Pharmacists can also run an interaction check when you fill a prescription, which is one more reason to keep every clinician informed.

How HealifyMD screens

• A full review of prescription, over-the-counter and supplement use before any prescription
• No methylene blue for anyone taking, or recently stopped, a serotonergic medicine
• G6PD screening guidance before starting (labs priced separately)
• Clear instructions to stop methylene blue and contact us if another clinician starts a serotonergic drug
• Follow-up to recheck your medicine list at each visit

About HealifyMD methylene blue

Methylene blue from HealifyMD is a compounded oral preparation made by a licensed U.S. pharmacy. Compounded medicines are not FDA-approved and have not been reviewed by the FDA for safety, effectiveness or quality, and using methylene blue for energy or focus is off-label. The price is from $149/month, or $299 for 3 months ($100/month), confirmed at your eligibility review. If you take an antidepressant, our clinicians can talk with you about other options instead.