Drug & supplement interaction

Cowslip + Meperidine, Promethazine

Meperidine, Promethazine brand names: Meprozine, Mepergan.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Cowslip and Meperidine, 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.

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Interaction report

Cowslip and Meperidine, 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 Meperidine, Promethazine and Cowslip 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Cowslip at all — not against Meperidine, Promethazine, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Cowslip safety at a glance

Cowslip overall Use caution Generally used in traditional teas, but human safety data are limited and some people may have allergic reactions.
Pregnancy Avoid Not enough safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoid use.

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

Still wondering about combining Meperidine, Promethazine and Cowslip? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
Everything else you take

See Every Supplement That Interacts With Meperidine, Promethazine

This page covers Cowslip only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Meperidine, Promethazine page lists 207 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Henbane (major).

By severity: 10 major · 160 moderate · 37 minor.

From our pharmacist’s overview on the Meperidine, Promethazine page

“Meprozine combines meperidine, an opioid painkiller, with promethazine, a sedating antihistamine, so it already slows the brain on two fronts. I would read this list of 207 supplements and herbal ingredients with genuine care, starting with the 10 rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Meperidine, Promethazine interaction page

One more smart check

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

We hold 21 real supplement products containing Cowslip, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cowslip. Even though Cowslip itself has no known interaction with Meperidine, Promethazine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Cowslip and Meperidine, 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 Cowslip
Top half

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

29 days ago today
Medication Meperidine, Promethazine
Top 25%

#485 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 Cowslip reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Cowslip and Meperidine, Promethazine records this page draws on were last updated June 22, 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 Cowslip

What is Cowslip?

  • Cough and chest congestion
  • Bronchitis and sinus problems
  • Trouble sleeping
  • Anxiety and restlessness
  • Headache

Cowslip is a traditional European herb whose flowers and roots have long been used as a tea or syrup, mainly for coughs and congestion. Solid human studies are very limited, so its benefits are not well proven. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Primula veris · Primulaceae · Flowers and roots · Tea, tincture, syrup, capsules, dried herb

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

Cowslip: dosing

There is no well-established standardized dose for cowslip. Traditional use has involved teas made from the flowers or preparations of the root, but reliable dosing information from research is lacking.If you choose to use a cowslip product, follow the directions on the product label and do not exceed the suggested amount.

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

Read the full Cowslip monograph & all interactions
Keep checking

Other Drugs & Cowslip

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Cowslip References

The 3 references that drive our Cowslip 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. Neubauer N, Marz RW. Placebo-controlled, randomized, double-blind, clincal trial with Sinupret sugar coated tablets on the basis of a therapy with antibiotics and decongestant nasal drops in acute sinusitis. Phytomedicine 1994;1:177-81.
  2. Marz RW, Ismail C, Popp MA. Action profile and efficacy of a herbal combination preparation for the treatment of sinusitis. Wien Med Wochenschr 1999;149:202-8.
  3. Peric A, Kovacevic SV, Gacesa D, Peric AV. Efficacy and safety of combined treatment of acute rhinosinusitis by herbal medicinal product Sinupret and mometasone furoate nasal spray. ENT Updates 2017;7(2):68-74. DOI

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 Cowslip and Meperidine, Promethazine Together: Common Questions

Is it safe to take Cowslip with Meperidine, Promethazine?
We do not list a known interaction between Cowslip and Meperidine, 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.
Does Meperidine, Promethazine interact with any supplements?
Yes. Meperidine, Promethazine has documented interactions with 207 supplements in our database — Cowslip is not one of them. The Meperidine, Promethazine interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Meperidine, Promethazine and Cowslip?

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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.