Drug & supplement interaction

Indian Snakeroot + Thioridazine

Thioridazine brand name: Mellaril.

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

Thioridazine falls into 2 drug categories that Indian Snakeroot can interact with; the most serious is rated major. Theoretically, concomitant use might increase the risk of adverse effects.

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

Indian Snakeroot and Thioridazine

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

Why Are There 2 Interactions?

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

Major

ANTIPSYCHOTIC DRUGS

1 of 2

Why this applies to Thioridazine

Thioridazine falls under ANTIPSYCHOTIC DRUGS — the group Indian Snakeroot interacts with.

Theoretically, concomitant use might increase the risk of adverse effects.
Concomitant use of neuroleptics with Indian snakeroot may potentiate the effects of these drugs, as well as the alkaloid constituents of Indian snakeroot.
Severity Major Likelihood Probable Evidence D

Interaction 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..

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

Here's the concern with pairing Indian snakeroot and thioridazine (Mellaril). The reserpine in snakeroot lowers blood pressure and calms the nervous system, and thioridazine does some overlapping things: it can drop your blood pressure and cause heavy sedation too. Stack them together and those effects can pile up, leaving you dizzy, faint when you stand, very drowsy, or low in mood.

I'll be honest, this is a theoretical caution based on how both substances work, not on hard clinical studies. But thioridazine already carries serious heart and rhythm warnings, so I wouldn't take chances. Please loop in your doctor or pharmacist before combining these rather than experimenting on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

2 of 2

Thioridazine also falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES.

Theoretically, Indian snakeroot might inhibit CYP2D6 enzymes and reduce the metabolism of CYP2D6 substrates.
Indian snakeroot contains small amounts of the drug yohimbine. In vitro research shows that yohimbine inhibits CYP2D6 enzyme activity.
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 clear thioridazine out of your system. Lab studies suggest Indian snakeroot (partly because of small amounts of yohimbine it contains) may slow that enzyme down. If thioridazine isn't cleared as quickly, levels in your blood could climb higher than intended, which can mean more side effects like drowsiness, dizziness, a dry mouth, or a drop in blood pressure when you stand up.

What makes me extra cautious is that thioridazine can affect the heart's rhythm (a longer QT interval), and higher levels raise that risk. This is theoretical, based only on lab research, not real patient cases, so don't panic. Still, please loop in your doctor or pharmacist before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. VandenBrink, B. M., Foti, R. S., Rock, D. A., Wienkers, L. C., and Wahlstrom, J. L. Prediction of CYP2D6 drug interactions from in vitro data: evidence for substrate-dependent inhibition. Drug Metab Dispos. 2012;40(1):47-53. 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

Indian Snakeroot Also Interacts With Other Medications

Indian Snakeroot has 82 major, 760 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.

Major 82 Moderate 760 No known interaction 1,988 (incl. Thioridazine)
Taking anything else?

Check Another of Your Medications Against Indian Snakeroot

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

From our Q&A

Questions About Indian Snakeroot 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 Indian Snakeroot 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 Indian Snakeroot 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 Indian Snakeroot as Part of a Dietary Supplement Product? Check It for Interactions

We hold 70 real supplement products containing Indian Snakeroot, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Indian Snakeroot. Your product may carry other ingredients that interact with Thioridazine too, on top of Indian Snakeroot — 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 Indian Snakeroot 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 Indian Snakeroot
Top half

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

29 days ago today
Medication Thioridazine
Steady interest

#1,567 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 Indian Snakeroot

What is Indian Snakeroot?

Indian Snakeroot
  • High blood pressure
  • Anxiety and stress
  • Insomnia
  • Agitation
  • Fever (traditional use)

Indian snakeroot is a traditional Ayurvedic plant that contains reserpine, a compound with real blood-pressure-lowering and sedative effects. Because its potent alkaloids can cause serious side effects like depression and very low blood pressure, it should never be used without medical supervision. It is not a safe or simple home remedy, and many countries restrict its use.

Read the full Indian Snakeroot 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 & Indian Snakeroot

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

82Major
760Moderate
0Minor
1,987No known interaction
82 Major 760 Moderate 1,987 No interaction
Major

82 interactions

Showing 60 of 82 major interactions — see all 82 on the Indian Snakeroot page.

Moderate

760 interactions

Showing 60 of 760 moderate interactions — see all 760 on the Indian Snakeroot page.

No interaction 1,987 drugs checked — show the list

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

Showing the 60 most looked-up of 1,987 medications checked with no known interaction — see the full Indian Snakeroot list.

See the full Indian Snakeroot 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
Indian Snakeroot 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 Indian Snakeroot and Thioridazine Together: Common Questions

Can you take Indian Snakeroot with Thioridazine?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Indian Snakeroot and Thioridazine?
Thioridazine belongs to more than one drug category, and Indian Snakeroot 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 Indian Snakeroot and Thioridazine interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

Still Have a Question About Thioridazine and Indian Snakeroot?

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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.