Drug & supplement interaction

Indian Snakeroot + Flupenthixol

Flupenthixol brand name: Fluanxol.

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

Flupenthixol falls into 3 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
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Indian Snakeroot and Flupenthixol

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

Why Are There 3 Interactions?

Indian Snakeroot interacts with whole categories of medication. Flupenthixol falls into 3 of those categories, so it can interact with Indian Snakeroot in 3 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 3

Why this applies to Flupenthixol

Flupenthixol 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 gist: Flupenthixol (Fluanxol) is an antipsychotic that already calms brain activity and can lower blood pressure. Indian snakeroot contains reserpine, which works in a similar lane by depleting certain nerve chemicals. Stacking the two could pile up the same effects, so you might feel extra drowsy or sedated, get dizzy or lightheaded when standing (low blood pressure), and in some cases low mood or depression could deepen.

This concern is theoretical, based on how both substances behave rather than hard studies, but the potential overlap is real enough to take seriously. Indian snakeroot is potent and restricted in many places. Please don't start or stop anything on your own; loop in your pharmacist or doctor before combining them.

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

CNS DEPRESSANTS

2 of 3

Flupenthixol also falls under CNS DEPRESSANTS.

Theoretically, taking Indian snakeroot might cause additive sedative effects.
Sedation and drowsiness have been reported in clinical trials using Indian snakeroot.
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 simple version: Flupenthixol is an antipsychotic that can already make you feel drowsy, calm, or a little sluggish. Indian snakeroot contains reserpine, which also has sedating effects and lowers blood pressure. Put the two together and those calming effects could stack up, so you might feel more tired, foggy, or lightheaded than usual, especially when standing up.

I'll be honest, this concern is mostly theoretical, based on how both work rather than firm studies on this exact pairing, so it isn't a reason to panic. Still, snakeroot is potent and reserpine has been linked to low mood, which matters with a mental-health medicine. Please don't start or stop anything on your own. Run it by your doctor or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Sheldon MB, Kotte JH. Effect of Rauwolfia serpentina and reserpine on the blood pressure in essential hypertension; a long-term double-blind study. Circulation. 1957 Aug;16(2):200-6.
  2. Vakil RJ. A clinical trial of Rauwolfia serpentina in essential hypertension. Br Heart J. 1949 Oct;11(4):350-5. PubMed
  3. Achor RW, Hanson NO, Gifford RW Jr. Hypertension treated with Rauwolfia serpentina (whole root) and with reserpine; controlled study disclosing occasional severe depression. J Am Med Assoc. 1955 Oct 29;159(9):841-5. PubMed
  4. Wilkins RW, Judson WE. The use of Rauwolfia serpentina in hypertensive patients. N Engl J Med. 1953 Jan 8;248(2):48-53.
Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

3 of 3

Flupenthixol 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 basic idea with these two. Your body uses an enzyme called CYP2D6 to help break down and clear Flupenthixol (Fluanxol). Indian snakeroot contains a small amount of yohimbine, and in lab tests yohimbine can slow that same enzyme down. If CYP2D6 is partly blocked, Flupenthixol could clear more slowly and build up a bit in your system. Since Flupenthixol is an active drug (not a prodrug), more of it sticking around means stronger effects.

In real life that might show up as extra drowsiness, dizziness, low blood pressure, restlessness, or stiffness. On top of that, snakeroot itself lowers blood pressure and can cause sedation, so the two can pile up. Worth noting: this is based only on lab data, not human studies, so it's theoretical. Still, both can affect blood pressure and mood, so please run this combination past your pharmacist or doctor before mixing 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 Flupenthixol 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. Flupenthixol)
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.

Everything else you take

See Every Supplement That Interacts With Flupenthixol

This page covers Indian Snakeroot only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Flupenthixol page lists 205 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 15 major · 178 moderate · 12 minor.

Open the Flupenthixol 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 Flupenthixol 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 Flupenthixol 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

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

29 days ago today
Medication Flupenthixol
Top 25%

#473 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
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 Flupenthixol, 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 Flupenthixol supplement interactions › Every supplement checked against Flupenthixol, 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 Indian Snakeroot and Flupenthixol Together: Common Questions

Can you take Indian Snakeroot with Flupenthixol?
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 3 interactions listed for Indian Snakeroot and Flupenthixol?
Flupenthixol 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 Flupenthixol 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

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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.