Drug & supplement interaction

Ceylon Leadwort + Haloperidol

Haloperidol brand name: Haldol.

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

Haloperidol falls into 3 drug categories that Ceylon Leadwort can interact with; the most serious is rated moderate. Plumbagin, a constituent of Ceylon leadwort, has been shown to inhibit cytochrome P450 2D6 (CYP2D6) in vitro.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Ceylon Leadwort and Haloperidol

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Ceylon Leadwort interacts with whole categories of medication. Haloperidol falls into 3 of those categories, so it can interact with Ceylon Leadwort in 3 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 3

Why this applies to Haloperidol

Haloperidol falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Ceylon Leadwort interacts with.

Plumbagin, a constituent of Ceylon leadwort, has been shown to inhibit cytochrome P450 2D6 (CYP2D6) in vitro. So far, this interaction has not been reported in humans. Theoretically, Ceylon leadwort might increase the levels of drugs metabolized by CYP2D6. Some drugs metabolized by CYP2D6 include amitriptyline (Elavil), codeine, desipramine (Norpramin), flecainide (Tambocor), fluoxetine (Prozac), ondansetron (Zofran), tramadol (Ultram), and others.
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

Your body relies in part on an enzyme called CYP2D6 to break down haloperidol. Lab research suggests plumbagin (a compound in Ceylon Leadwort) can block that enzyme. If that happened in real life, your haloperidol could clear more slowly and build up, making side effects more likely. Think along the lines of heavy drowsiness, dizziness, muscle stiffness, restlessness, tremors, or other involuntary movements.

Here's the reassuring part: this is based only on test-tube data, not real human cases, so it's theoretical. Still, haloperidol is a potent medicine, so I wouldn't take chances. Please check with your pharmacist or doctor before pairing the two, and don't change your haloperidol on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Chen A, Zhou X, Tang S, Liu M, Wang X. Evaluation of the inhibition potential of plumbagin against cytochrome P450 using LC-MS/MS and cocktail approach. Sci Rep. 2016 Jun 22;6:28482. PubMed
Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

2 of 3

Haloperidol also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Plumbagin, a constituent of Ceylon leadwort, has been shown to inhibit cytochrome P450 1A2 (CYP1A2) in vitro. So far, this interaction has not been reported in humans. Theoretically, Ceylon leadwort might increase the levels of drugs metabolized by CYP1A2. Some substrates of CYP1A2 include clozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), zileuton (Zyflo), zolmitriptan (Zomig), and others.
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 gist for Haloperidol (Haldol): your body uses a liver enzyme called CYP1A2 to help clear it. A compound in Ceylon Leadwort, called plumbagin, has been shown in lab dish studies only to slow that enzyme down. In theory, a slower enzyme means haloperidol could build up in your system, which might push up the chances of side effects like drowsiness, dizziness, muscle stiffness, tremor, restlessness, or the involuntary movements this medicine can sometimes cause.

The honest part: this has not been seen in real people yet, so it's a theoretical concern, not a proven one. Still, haloperidol isn't a drug to gamble with. Please check with your pharmacist or doctor before pairing the two, rather than changing anything on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Chen A, Zhou X, Tang S, Liu M, Wang X. Evaluation of the inhibition potential of plumbagin against cytochrome P450 using LC-MS/MS and cocktail approach. Sci Rep. 2016 Jun 22;6:28482. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 3

Haloperidol also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Plumbagin, a constituent of Ceylon leadwort, has been shown to inhibit cytochrome P450 3A4 (CYP3A4) in vitro. So far, this interaction has not been reported in humans. Theoretically, Ceylon leadwort might increase the levels of drugs metabolized by CYP3A4. Some drugs metabolized by CYP3A4 include lovastatin (Mevacor), clarithromycin (Biaxin), indinavir (Crixivan), sildenafil (Viagra), triazolam (Halcion), and numerous others.
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: your body partly uses an enzyme called CYP3A4 to clear Haloperidol (Haldol). Plumbagin, the active compound in Ceylon Leadwort, has been shown in lab dish studies to slow that enzyme down. If that same slowdown happened in a person, Haldol could build up a bit higher than expected, which in theory might mean stronger side effects like heavy drowsiness, muscle stiffness or restlessness, tremor, or those uncomfortable involuntary movements this drug is known for.

The big caveat: this is only based on test-tube research, not real people, so we honestly don't know if it matters in practice. I wouldn't panic, but I also wouldn't pair them on your own. Please run it by your pharmacist or doctor first before adding this supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Chen A, Zhou X, Tang S, Liu M, Wang X. Evaluation of the inhibition potential of plumbagin against cytochrome P450 using LC-MS/MS and cocktail approach. Sci Rep. 2016 Jun 22;6:28482. 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

Ceylon Leadwort Also Interacts With Other Medications

Ceylon Leadwort has 1,096 moderate known drug interactions in our database — the Haloperidol one above is among them. If you take anything else, check it against the full list below.

Moderate 1,096 No known interaction 1,734 (incl. Haloperidol)
Taking anything else?

Check Another of Your Medications Against Ceylon Leadwort

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

Everything else you take

See Every Supplement That Interacts With Haloperidol

This page covers Ceylon Leadwort only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Haloperidol page lists 211 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 · 157 moderate · 43 minor.

From our pharmacist’s overview on the Haloperidol page

“Haloperidol (Haldol) is a potent antipsychotic prescribed for schizophrenia and severe agitation, and the 211 supplements on this list warrant genuine care, starting with the 11 rated major. Most of the trouble runs through the liver enzymes that clear haloperidol from the body.”

Reviewed by 2 · Jul 18, 2026

Open the Haloperidol interaction page

One more smart check

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

We hold 96 real supplement products containing Ceylon Leadwort, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Ceylon Leadwort. Your product may carry other ingredients that interact with Haloperidol too, on top of Ceylon Leadwort — 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 Ceylon Leadwort and Haloperidol 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 Ceylon Leadwort
Top half

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

29 days ago today
Medication Haloperidol
Top half

#1,355 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 Ceylon Leadwort

What is Ceylon Leadwort?

  • Digestive complaints and poor appetite
  • Skin conditions and wounds (applied to the skin)
  • Joint pain and swelling
  • Traditional 'metabolism-boosting' tonics
  • Antimicrobial folk remedy

Ceylon Leadwort (Plumbago zeylanica) is a plant long used in Ayurvedic and other traditional medicine systems, mainly for digestion, skin problems, and pain. Solid human studies are lacking, and the plant contains plumbagin, a compound that can irritate skin and tissues and may be unsafe in larger amounts. Talk to a pharmacist or doctor before using it, and avoid it in pregnancy.

Read the full Ceylon Leadwort monograph & all interactions
Medication

About Haloperidol

What Is Haloperidol Used For?

Brand name: Haldol

Haloperidol is used to manage symptoms of psychotic disorders and to control the tics and vocal outbursts of Tourette's disorder in both children and adults.

In children, it is also used for severe combative or explosive behavior problems, and for hyperactivity with conduct disorders — but only when other treatments like therapy or non-antipsychotic medications have not worked.

See full Haloperidol drug information
Keep checking

Other Drugs & Ceylon Leadwort

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

0Major
1,096Moderate
0Minor
1,733No known interaction
1,096 Moderate 1,733 No interaction
Moderate

1,096 interactions

Showing 60 of 1,096 moderate interactions — see all 1,096 on the Ceylon Leadwort page.

No interaction 1,733 drugs checked — show the list

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

Showing the 60 most looked-up of 1,733 medications checked with no known interaction — see the full Ceylon Leadwort list.

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

Can you take Ceylon Leadwort with Haloperidol?
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 3 interactions listed for Ceylon Leadwort and Haloperidol?
Haloperidol belongs to more than one drug category, and Ceylon Leadwort 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 Ceylon Leadwort and Haloperidol 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 Haloperidol and Ceylon Leadwort?

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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.