Drug & supplement interaction

Tronadora + Promethazine

Promethazine brand name: Phenergan.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Tronadora and Promethazine in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Tronadora and Promethazine

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Promethazine and Tronadora in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Tronadora safety at a glance

Tronadora overall Use caution Limited human safety data; may affect blood sugar, so use with care and medical guidance.
Pregnancy Avoid Not enough safety information; avoid during pregnancy.
Breastfeeding Avoid No reliable safety data while breastfeeding; best avoided.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Promethazine and Tronadora? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Promethazine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Promethazine is filed under 4 classifications — including phenothiazines, anticholinergic drugs, photosensitizing drugs. Tronadora has documented interactions with 1 drug class — the most serious being antidiabetes drugs (moderate) — and none of Promethazine’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Tronadora Does Interact With Other Medications

Tronadora has 86 moderate known drug interactions in our database — Promethazine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 86 No known interaction 2,744 (incl. Promethazine)
Taking anything else?

Check Another of Your Medications Against Tronadora

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

What to actually watch for

No Interaction Found — But Data Suggests Tronadora and Promethazine May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • A skin rash Additional detail

    Tronadora

    “There is currently a limited amount of information available about adverse effects of tronadora. Topically, tronadora might cause allergic dermatitis.”

    Tronadora · Natural Medicines adverse-effect record, reported in dermatitis.

    1 source cited
    1. 96666. Lakshmi C. Fingertip eczema to pooja flowers: Allergic contact dermatitis to Tabernaemontana divaricata and Tecoma stans. Indian J Dermatol Venereol Leprol. 2015;81(5):514-6. PubMed

    “Topically, tronadora might cause allergic dermatitis. In one case report, an Indian woman that regularly plucked tronadora flowers as part of her morning pooja ritual developed allergic dermatitis.”

    Tronadora · Natural Medicines adverse-effect record, reported in dermatitis.

    1 source cited
    1. 96666. Lakshmi C. Fingertip eczema to pooja flowers: Allergic contact dermatitis to Tabernaemontana divaricata and Tecoma stans. Indian J Dermatol Venereol Leprol. 2015;81(5):514-6. PubMed

    Promethazine

    Listed in the ADVERSE REACTIONS section of the FDA label for Promethazine. Read the label on DailyMed ›

Effects for Promethazine come from the ADVERSE REACTIONS section of its FDA label; effects for Tronadora come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 22,361 voluntary FDA FAERS reports for Promethazine that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

From our Q&A

Questions About Tronadora or Promethazine

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

This page covers Tronadora only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Promethazine page lists 83 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Scopolia (major), Alfalfa (moderate) and Angel's Trumpet (moderate).

By severity: 3 major · 57 moderate · 23 minor.

From our pharmacist’s overview on the Promethazine page

“Promethazine (Phenergan) is a phenothiazine antihistamine used for allergies, nausea, and motion sickness, and it is strongly anticholinergic on its own, causing dry mouth, blurred vision, drowsiness, and constipation. That is why the 83 supplements and herbs on this list deserve real attention, starting with the three rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Promethazine interaction page

How much people look this up

Where Tronadora and Promethazine 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 Tronadora
Steady interest

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

29 days ago today
Medication Promethazine
Top half

#1,330 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Tronadora reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Tronadora and Promethazine records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Tronadora

What is Tronadora?

  • Blood sugar control / diabetes
  • Digestive complaints
  • Mild fever
  • Yeast or fungal concerns
  • Traditional 'tonic' use

Tronadora (Tecoma stans) is a flowering shrub used in Mexican and Latin American folk medicine, most often as a tea for diabetes and digestive complaints. Human evidence is very limited, so it should not replace proven treatments. Because it may affect blood sugar and its safety is not well studied, talk to your pharmacist or doctor before using it—and avoid it during pregnancy and breastfeeding.

Tecoma stans · Bignoniaceae · Leaves, flowers, and sometimes roots and bark · Tea (infusion), dried herb, capsules, liquid extracts

An interaction check asks whether these two react with each other — it does not ask whether Tronadora is a good idea for someone in your situation. Here is what our Tronadora record says about it on its own.

Tronadora: dosing

There is no established, standardized dose for Tronadora. Traditional use is often as a tea made from the dried leaves or flowers, but the amount of active compounds can vary a lot between products and batches.If you choose to use it, follow the directions on the product label and start low.

From our Tronadora monograph — the full record covers uses, side effects and every documented interaction.

Read the full Tronadora monograph & all interactions
Medication

About Promethazine

What Is Promethazine Used For?

Brand name: Phenergan

Promethazine is used for a wide range of conditions. Tablets, oral solution, and rectal suppositories (brands including Phenergan, Promethegan, and Phenadoz) are approved for seasonal and perennial allergic rhinitis, vasomotor rhinitis, allergic conjunctivitis, hives (urticaria), angioedema, dermographism, and allergic reactions to blood or plasma. They are also used for motion sickness (both prevention and active treatment), nausea and vomiting related to anesthesia and surgery, sedation, and as a helper medication alongside pain relievers after surgery.

Promethazine hydrochloride injection (brands including Phenergan and Promethazine HCl injection) is used for many of the same purposes but is reserved for situations where oral treatment is not possible — including allergic emergencies as an adjunct to epinephrine, sedation during labor, and as an aid during certain surgical procedures such as bronchoscopy and eye surgery.

Most-Reported Side Effects for Promethazine

From FAERS, the FDA’s public side-effect reporting system (22,614 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Dependence 3,586 reports
Nausea 2,646 reports
Vomiting 1,802 reports
Fatigue 1,496 reports
Diarrhea 1,341 reports
See full Promethazine drug information
Keep checking

Other Drugs & Tronadora

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

0Major
86Moderate
0Minor
2,743No known interaction
86 Moderate 2,743 No interaction
Moderate

86 interactions

Showing 60 of 86 moderate interactions — see all 86 on the Tronadora page.

No interaction 2,743 drugs checked — show the list

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

Showing the 60 most looked-up of 2,743 medications checked with no known interaction — see the full Tronadora list.

See the full Tronadora interactions page
See every supplement checked against Promethazine, ranked by severity
Evidence & sources

Tronadora References

The 7 references that drive our Tronadora monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Costantino L, Raimondi L, Pirisino R, et al. Isolation and pharmacological activities of the Tecoma stans alkaloids. Farmaco 2003;58:781-5. PubMed
  2. Meckes-Lozoya M, Ibanez-Camacho R. Hepatic glycogenolysis produced by intraperitoneal administration of total extract of Tecoma stans in rats. Arch Invest Med (Mex) 1985;16:387-9.
  3. Roman-Ramos R, Flores-Saenz JL, Partida-Hernandez G, et al. Experimental study of the hypoglycemic effect of some antidiabetic plants. Arch Invest Med (Mex) 1991;22:87-93.
  4. Lakshmi C. Fingertip eczema to pooja flowers: Allergic contact dermatitis to Tabernaemontana divaricata and Tecoma stans. Indian J Dermatol Venereol Leprol. 2015;81(5):514-6. PubMed
  5. Pascoe-González S, Ramos-Zavala MG, Buenrostro Ahued MA, et al. Administration of herbarium mixture (Guazuma ulmifolia/Tecoma stans) on metabolic profile in type 2 diabetes mellitus patients: A randomized, double-blind, placebo-controlled trial. J Med Foo
  6. Gupta A, Behl T, Sehgal A, et al. Elucidating the neuroprotective effect of Tecoma stans leaf extract in STZ-induced diabetic neuropathy. Evid Based Complement Alternat Med 2022;2022:3833392. PubMed
  7. Morales-Ferra DL, Zavala-Sánchez MÁ, Jiménez-Ferrer E, González-Cortazar M, Zamilpa A. Effect of Tecoma stans (L.) Juss. ex Kunth in a murine model of metabolic syndrome. Plants (Basel) 2022;11(14):1794. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Tronadora and Promethazine Together: Common Questions

Is it safe to take Tronadora with Promethazine?
We do not list a known interaction between Tronadora and Promethazine. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Tronadora and Promethazine have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Tronadora and Promethazine combination checked?
Interactions in our licensed database are recorded against drug classes. Promethazine is filed under 4 classifications, and Tronadora has documented interactions with 1 drug class — none of Promethazine's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Tronadora interact with any other medications?
Yes. Tronadora has 86 documented drug interactions in our database — Promethazine is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Promethazine interact with any supplements?
Yes. Promethazine has documented interactions with 83 supplements in our database — Tronadora is not one of them. The Promethazine interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Tronadora monograph Uses, safety profile, and every drug interaction in one place Promethazine drug information The full plain-English guide to this medication Promethazine supplement interactions Every supplement checked against Promethazine, 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 References The 7 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Promethazine and Tronadora?

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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.