Drug & supplement interaction

Garcinia + Methylene Blue

Methylene Blue brand names: Urolene Blue, Provayblue.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Garcinia has a moderate interaction with Methylene Blue. Theoretically, combining garcinia with other serotonergic drugs might increase the risk of serotonergic side effects, including serotonin syndrome.

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

Garcinia and Methylene Blue

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

Moderate

SEROTONERGIC DRUGS

Why this applies to Methylene Blue

Methylene Blue falls under SEROTONERGIC DRUGS — the group Garcinia interacts with.

Theoretically, combining garcinia with other serotonergic drugs might increase the risk of serotonergic side effects, including serotonin syndrome.
In one report, a patient experienced serotonin syndrome after taking garcinia extract (60% hydroxycitric acid) 1000 mg daily in combination with escitalopram 20 mg, which had been taken for a year. The patient was switched to sertraline 50 mg daily and again experienced serotonin syndrome.
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 something a lot of people don't realize about methylene blue: even though we think of it as a dye or a treatment for a blood condition called methemoglobinemia, it's also a fairly strong MAO inhibitor. That means it slows the breakdown of serotonin in your body. Garcinia (and its main ingredient, hydroxycitric acid) has been linked, in a few anecdotal reports, to raising serotonin activity too.

Stack those two together and you could, in theory, push serotonin too high. That's called serotonin syndrome, and signs include agitation, sweating, fast heartbeat, shivering, muscle twitching, and confusion. The evidence here is thin (just a couple of case reports with Garcinia), but methylene blue itself is a well-known serotonin risk, so it's worth a quick chat with your doctor or pharmacist before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lopez AM, Kornegay J, Hendrickson RG. Serotonin Toxicity Associated with Garcinia cambogia Over-the-counter Supplement. J Med Toxicol. 2014 Apr 4. [Epub ahead of print]. PubMed

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

Garcinia Also Interacts With Other Medications

Garcinia has 703 moderate known drug interactions in our database — the Methylene Blue one above is one of them. If you take anything else, check it against the full list below.

Moderate 703 No known interaction 2,127 (incl. Methylene Blue)
Taking anything else?

Check Another of Your Medications Against Garcinia

Covers the 2,830 medications we’ve checked against Garcinia. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Methylene Blue

This page covers Garcinia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methylene Blue page lists 38 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Lithium (major), 5-htp (moderate), Acetyl-l-carnitine (moderate) and Ayahuasca (moderate).

By severity: 2 major · 25 moderate · 11 minor.

From our pharmacist’s overview on the Methylene Blue page

“The pairing I would worry about first with methylene blue (Urolene Blue, Provayblue) is anything that raises serotonin, and lithium heads that group with a major rating. Methylene blue inhibits monoamine oxidase A, the enzyme that breaks serotonin down, so combining it with serotonin-boosting supplements can tip someone into serotonin…”

Reviewed by 2 · Jul 18, 2026

Open the Methylene Blue interaction page

One more smart check

Taking Garcinia as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,374 real supplement products containing Garcinia, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Garcinia. Your product may carry other ingredients that interact with Methylene Blue too, on top of Garcinia — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Garcinia and Methylene Blue 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 Garcinia
Top 25%

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

29 days ago today
Medication Methylene Blue
Top 5%

#46 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 Garcinia

What is Garcinia?

Garcinia
  • Weight loss
  • Appetite suppression
  • Curbing sugar and carb cravings
  • Supporting metabolism
  • Traditional cooking and souring agent

Garcinia is a tropical fruit whose rind contains hydroxycitric acid (HCA), widely marketed for weight loss and appetite control. The scientific evidence is weak and mixed, with most studies showing only small or no meaningful weight effects, and rare reports of liver problems raise safety concerns. Talk to a pharmacist or doctor before trying it, especially if you have liver issues, are pregnant, or are breastfeeding.

Read the full Garcinia monograph & all interactions
Keep checking

Other Drugs & Garcinia

Browse every other medication we’ve checked against Garcinia — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
703Moderate
0Minor
2,126No known interaction
703 Moderate 2,126 No interaction
Moderate

703 interactions

Showing 60 of 703 moderate interactions — see all 703 on the Garcinia page.

No interaction 2,126 drugs checked — show the list

We also checked Garcinia against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,126 medications checked with no known interaction — see the full Garcinia list.

See the full Garcinia interactions page
See every supplement checked against Methylene Blue, ranked by severity
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

Keep exploring
Garcinia monograph › Uses, safety, and every drug interaction in one place Methylene Blue supplement interactions › Every supplement checked against Methylene Blue, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Garcinia and Methylene Blue Together: Common Questions

Can you take Garcinia with Methylene Blue?
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 Garcinia and Methylene Blue 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 Methylene Blue and Garcinia?

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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.