Drug & supplement interaction

Indian Snakeroot + Promazine

Promazine brand name: Sparine.

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

Indian Snakeroot has a major interaction with Promazine. Theoretically, concomitant use might increase the risk of adverse effects.

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

Indian Snakeroot and Promazine

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

Major

ANTIPSYCHOTIC DRUGS

Why this applies to Promazine

Promazine 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 thing to know if you're taking Promazine (Sparine), an older antipsychotic, alongside Indian snakeroot. Both of these lower the activity of certain brain and nerve chemicals and both can relax blood vessels and cause sedation. Stack them together and those effects can pile up rather than cancel out.

In real-world terms, that could mean blood pressure dropping too low (lightheadedness, dizziness when you stand, even fainting), heavier drowsiness, and possibly low mood or depression, which both substances are known to trigger. This concern is based on how the two work in theory rather than on solid studies, so it's not a guarantee. Still, snakeroot is potent and not a casual home remedy. Please loop in your doctor or pharmacist before combining them, and don't change your Promazine 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.

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 Promazine one above is one of them. If you take anything else, check it against the full list below.

Major 82 Moderate 760 No known interaction 1,988 (incl. Promazine)
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 Promazine

This page covers Indian Snakeroot only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Promazine page lists 90 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Rauvolfia Vomitoria (major), Scopolia (major) and Alfalfa (moderate).

By severity: 5 major · 61 moderate · 24 minor.

From our pharmacist’s overview on the Promazine page

“Promazine (Sparine) is an older antipsychotic in the phenothiazine family, and the 90 supplements and herbs on this page deserve real attention before you add any of them. The biggest cluster, 30 ingredients, shares promazine's anticholinergic side effects, so pairing them can pile on dry mouth, constipation, and confusion; henbane car…”

Reviewed by 2 · Jul 18, 2026

Open the Promazine 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 Promazine 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 Promazine 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

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

29 days ago today
Medication Promazine
Steady interest

#2,765 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 Promazine, 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 Promazine supplement interactions › Every supplement checked against Promazine, 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 Promazine Together: Common Questions

Can you take Indian Snakeroot with Promazine?
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.
How serious is the Indian Snakeroot and Promazine 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 Promazine 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.