Drug & supplement interaction

Methylene Blue + Scopolamine

Scopolamine brand names: Scopace, Scopolamine Injection, Transderm Scop.

Moderate Interaction
The bottom line Moderate

Methylene Blue has a moderate interaction with Scopolamine. Concomitant use may increase anticholinergic effects and adverse effects.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Methylene Blue and Scopolamine

Here is the interaction we found between these two, with the evidence behind it.

Moderate

Anticholinergic Drugs

Why this applies to Scopolamine

Scopolamine falls under Anticholinergic Drugs — the group Methylene Blue interacts with.

Concomitant use may increase anticholinergic effects and adverse effects. In a case report, a critically-ill male in his mid-60s developed a toxicological process attributed to anticholinergic syndrome following treatment with methylene blue for vasoplegia. Symptoms included anhidrosis, fever, lactic acidosis, mucosal dryness, and pupil dilation. Potential exacerbating factors included renal failure and use of fentanyl intra-operatively.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the short version: Scopolamine (like the Transderm Scop patch) already works by blocking acetylcholine, so it naturally causes drying-type effects such as dry mouth, blurred vision, dilated pupils, drowsiness, and sometimes a fast heartbeat. Methylene blue can add its own anticholinergic-like burden on top, so combining the two may make those effects stronger. In one hospital case, a critically ill man given methylene blue developed a full anticholinergic picture (no sweating, fever, very dry mouth, and dilated pupils).

That said, this is based on a single case report in a very sick patient, so the evidence is weak and this is not a guaranteed problem. Still, if you use scopolamine and are considering methylene blue, please check with your pharmacist or doctor first rather than combining them on your own.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Methylene Blue Also Interacts With Other Medications

Methylene Blue has 314 moderate known drug interactions in our database — the Scopolamine one above is one of them. If you take anything else, check it against the full list below.

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.

From our Q&A

Questions About Methylene Blue or Scopolamine

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 Scopolamine, 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 Scopolamine

This page covers Methylene Blue only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Scopolamine page lists 51 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Henbane (major), Scopolia (major) and Angel's Trumpet (moderate).

By severity: 4 major · 34 moderate · 13 minor.

From our pharmacist’s overview on the Scopolamine page

“Scopolamine, the motion sickness medicine most people wear as the Transderm Scop patch, sits on the serious end of supplement interactions, so learn the four major entries first. Most of the 51 ingredients here, 30 of them, pile the same anticholinergic side effects on top of the drug: dry mouth, blurred vision, constipation, confusion.”

Reviewed by 2 · Jul 18, 2026

Open the Scopolamine interaction page

How much people look this up

Where Methylene Blue and Scopolamine 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 25%

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

29 days ago today
Medication Scopolamine
Top 10%

#202 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.

Supplement

About Methylene Blue

What is Methylene Blue?

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.

Read the full Methylene Blue monograph & all interactions
Medication

About Scopolamine Transdermal Patch

What Is Scopolamine Transdermal Patch Used For?

Brand names: Scopace, Scopolamine Injection, Transderm Scop

Scopolamine Transdermal System (also sold as Transderm Scōp) is approved for adults to prevent nausea and vomiting caused by motion sickness. You apply it before travel to help stop queasiness before it starts.

It is also used to prevent post-operative nausea and vomiting (PONV) — the nausea and vomiting that can follow surgery, anesthesia, or opioid pain medicines. Transderm Scōp is applied the evening before surgery (for surgeries other than cesarean section) and removed 24 hours after the procedure.

See full Scopolamine Transdermal Patch 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
314Moderate
0Minor
2,515No known interaction
Moderate

314 interactions

Showing 60 of 314 moderate interactions — see all 314 on the Methylene Blue page.

No interaction 2,515 drugs checked — show the list
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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Pharmacist Counseling Corner

Taking Methylene Blue and Scopolamine Together: Common Questions

Can you take Methylene Blue with Scopolamine?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Methylene Blue and Scopolamine interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Scopolamine and Methylene Blue?

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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.