Drug & supplement interaction

Garcinia + Dextromethorphan

Dextromethorphan brand names: Hold, Benylin Adult, Benylin Pediatric, Theraflu Thin Strips Long Acting Cough, Neo Citran Thin Strips Cough.

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

Garcinia has a moderate interaction with Dextromethorphan. 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 Dextromethorphan

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

Moderate

SEROTONERGIC DRUGS

Why this applies to Dextromethorphan

Dextromethorphan 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 the connection worth knowing: dextromethorphan, the cough suppressant in many over-the-counter cold products, does more than quiet a cough. It also nudges serotonin activity in the brain. Garcinia has been linked, in rare reports, to serotonin syndrome, which is too much serotonin signaling. Stacking the two together could, in theory, raise that risk.

I'll be honest with you though: this is built on very thin evidence (a single case report involving an antidepressant, not dextromethorphan itself). So the real-world risk for occasional cough syrup is likely low. Still, watch for things like agitation, a racing heart, sweating, shivering, muscle twitching, or feeling confused. If those show up, stop and seek care. When in doubt, check with your 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 Dextromethorphan 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. Dextromethorphan)
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.

From our Q&A

Questions About Garcinia or Dextromethorphan

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Garcinia or Dextromethorphan, 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 Dextromethorphan

This page covers Garcinia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dextromethorphan page lists 171 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Lithium (major), St. John's Wort (major) and 1,3-dmaa (moderate).

By severity: 4 major · 125 moderate · 42 minor.

From our pharmacist’s overview on the Dextromethorphan page

“A glass of grapefruit juice can push dextromethorphan (Benylin, Hold, and other cough medicines) to higher levels than intended, one of four major-rated entries among the 171 supplements and herbs on file, and the list as a whole warrants real care. Most interactions trace back to the liver enzymes (CYP3A4 and CYP2D6) that clear dextro…”

Reviewed by 2 · Jul 18, 2026

Open the Dextromethorphan 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 Dextromethorphan 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 Dextromethorphan 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%

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

29 days ago today
Medication Dextromethorphan
Top 5%

#80 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
Medication

About Dextromethorphan

What Is Dextromethorphan Used For?

Brand names: Hold, Benylin Adult, Benylin Pediatric, Theraflu Thin Strips Long Acting Cough, Neo Citran Thin Strips Cough

Dextromethorphan temporarily relieves cough due to minor throat and bronchial irritation, such as the kind that comes with the common cold or breathing in irritants. It also helps reduce the urge to cough so you — or your child — can get to sleep.

Some products, including CVS Long Acting Cough and Premier Value Tussin Cough oral liquids, are also indicated to help loosen phlegm (mucus) and thin bronchial secretions to help drain the airways.

See full Dextromethorphan drug information
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 Dextromethorphan, 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 Dextromethorphan supplement interactions › Every supplement checked against Dextromethorphan, ranked by severity Dextromethorphan drug information › The full plain-English guide to this medication 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 Dextromethorphan Together: Common Questions

Can you take Garcinia with Dextromethorphan?
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 Dextromethorphan 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 Dextromethorphan 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.