Drug & supplement interaction

Boswellia Serrata + Thioridazine

Thioridazine brand name: Mellaril.

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

Thioridazine falls into 2 drug categories that Boswellia Serrata can interact with; the most serious is rated moderate. Theoretically, Boswellia serrata might increase the levels of CYP2D6 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Boswellia Serrata and Thioridazine

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Boswellia Serrata interacts with whole categories of medication. Thioridazine falls into 2 of those categories, so it can interact with Boswellia Serrata in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

1 of 2

Why this applies to Thioridazine

Thioridazine falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Boswellia Serrata interacts with.

Theoretically, Boswellia serrata might increase the levels of CYP2D6 substrates.
In vitro research shows that Boswellia serrata gum resin inhibits CYP2D6 enzymes.
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 concern with pairing these two. Your body relies on a liver enzyme called CYP2D6 to break down thioridazine and clear it out. In lab studies, boswellic acids (the active part of Boswellia) appear to slow that same enzyme down. If that happens in real life, thioridazine could build up to higher levels than intended.

Why does that matter? Thioridazine carries a real risk of affecting the heart's rhythm (a change called QT prolongation), and higher levels can also mean more drowsiness, dizziness, or low blood pressure. The good news is this is only a theoretical concern based on lab data, not proven in people. Still, because thioridazine is a sensitive drug, I'd run this past your pharmacist or doctor before adding Boswellia.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Frank A, Unger M. Analysis of frankincense from various Boswellia species with inhibitory activity on human drug metabolising cytochrome P450 enzymes using liquid chromatography mass spectrometry after automated on-line extraction. J Chromatogr A 2006;111 PubMed
Moderate

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES

2 of 2

Thioridazine also falls under CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES.

Theoretically, Boswellia serrata might increase the levels of CYP2C19 substrates.
In vitro research shows that Boswellia serrata gum resin inhibits CYP2C19 enzymes.
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 with thioridazine (Mellaril): your body uses an enzyme called CYP2C19 to help clear this drug. In lab tests, boswellic acids from Boswellia appear to slow that enzyme down. If that holds true in people, thioridazine could build up a bit and hit harder, meaning more of its usual side effects like drowsiness, dizziness, dry mouth, or a faster heartbeat.

What makes me extra cautious here is that thioridazine can affect heart rhythm (a QT issue), so even modest increases deserve respect. That said, this warning is theoretical and comes only from test-tube research, not real patients. Don't stop or change anything on your own. Just give your pharmacist or doctor a heads-up before you start Boswellia so they can keep an eye on you.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Frank A, Unger M. Analysis of frankincense from various Boswellia species with inhibitory activity on human drug metabolising cytochrome P450 enzymes using liquid chromatography mass spectrometry after automated on-line extraction. J Chromatogr A 2006;111 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

Boswellia Serrata Also Interacts With Other Medications

Boswellia Serrata has 951 moderate known drug interactions in our database — the Thioridazine one above is among them. If you take anything else, check it against the full list below.

Moderate 951 No known interaction 1,879 (incl. Thioridazine)
Taking anything else?

Check Another of Your Medications Against Boswellia Serrata

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

From our Q&A

Questions About Boswellia Serrata or Thioridazine

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

This page covers Boswellia Serrata only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Thioridazine page lists 168 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 11 major · 125 moderate · 32 minor.

From our pharmacist’s overview on the Thioridazine page

“Thioridazine (Mellaril) is an older antipsychotic already known for disturbing the heart's rhythm, and the supplements that worry me most here do the same thing, stretching the QT interval further. Grapefruit in large amounts sits in that group, alongside ephedra and several other major-rated entries.”

Reviewed by 2 · Jul 18, 2026

Open the Thioridazine interaction page

One more smart check

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

We hold 1,914 real supplement products containing Boswellia Serrata, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Boswellia Serrata. Your product may carry other ingredients that interact with Thioridazine too, on top of Boswellia Serrata — 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 Boswellia Serrata and Thioridazine 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 Boswellia Serrata
Top 10%

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

29 days ago today
Medication Thioridazine
Steady interest

#2,440 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 Boswellia Serrata

What is Boswellia Serrata?

Boswellia Serrata
  • Osteoarthritis joint pain
  • Rheumatoid arthritis
  • Inflammation
  • Asthma
  • Inflammatory bowel conditions

Boswellia serrata is a tree resin used in traditional medicine, mainly for joint pain and inflammation. Some studies suggest it may help with osteoarthritis symptoms, but the overall evidence is limited and more research is needed. It is generally well tolerated, but you should check with your pharmacist or doctor before using it, especially during pregnancy or breastfeeding.

Read the full Boswellia Serrata monograph & all interactions
Medication

About Thioridazine

What Is Thioridazine Used For?

Brand name: Mellaril

Thioridazine Hydrochloride tablets are used for the management of schizophrenia — but only in patients who have already tried at least two other antipsychotic medications without adequate results, either because those drugs didn't work well enough or caused intolerable side effects.

Because thioridazine carries serious heart-rhythm risks, it is considered a last-resort option for schizophrenia, not a first-line treatment. It is not approved for dementia-related psychosis or any other psychiatric condition.

See full Thioridazine drug information
Keep checking

Other Drugs & Boswellia Serrata

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

0Major
951Moderate
0Minor
1,878No known interaction
951 Moderate 1,878 No interaction
Moderate

951 interactions

Showing 60 of 951 moderate interactions — see all 951 on the Boswellia Serrata page.

No interaction 1,878 drugs checked — show the list

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

Showing the 60 most looked-up of 1,878 medications checked with no known interaction — see the full Boswellia Serrata list.

See the full Boswellia Serrata interactions page
See every supplement checked against Thioridazine, 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
Boswellia Serrata monograph › Uses, safety, and every drug interaction in one place Thioridazine supplement interactions › Every supplement checked against Thioridazine, ranked by severity Thioridazine 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 Boswellia Serrata and Thioridazine Together: Common Questions

Can you take Boswellia Serrata with Thioridazine?
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.
Why are there 2 interactions listed for Boswellia Serrata and Thioridazine?
Thioridazine belongs to more than one drug category, and Boswellia Serrata interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Boswellia Serrata and Thioridazine 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 Thioridazine and Boswellia Serrata?

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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.