Drug & supplement interaction

Fool's Parsley + Meperidine, Promethazine

Meperidine, Promethazine brand names: Meprozine, Mepergan.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Fool's Parsley 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.

Know someone taking this? Share
Interaction report

Fool's Parsley 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 Fool's Parsley 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 Fool's Parsley 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.

Fool's Parsley safety at a glance

Fool's Parsley overall Avoid The raw plant is toxic and easily confused with edible parsley, so it should not be consumed.
Pregnancy Likely Unsafe When used orally due to potential for poisoning. Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally due to potential for poisoning. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Meperidine, Promethazine and Fool's Parsley? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
Special populations

Fool's Parsley in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When used orally due to potential for poisoning.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Everything else you take

See Every Supplement That Interacts With Meperidine, Promethazine

This page covers Fool's Parsley 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

How much people look this up

Where Fool's Parsley 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 Fool's Parsley
Steady interest

#1,017 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Meperidine, Promethazine
Top 25%

#462 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 Fool's Parsley reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Fool's Parsley 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 Fool's Parsley

What is Fool's Parsley?

  • Digestive complaints (traditional/homeopathic)
  • Diarrhea in children (homeopathic tradition)
  • Nausea and vomiting (homeopathic tradition)
  • Restlessness (homeopathic tradition)

Fool's Parsley is a poisonous weed that closely resembles edible parsley and has no proven medicinal benefit. The raw plant is toxic and should never be eaten; the only modern use is in highly diluted homeopathic products, which lack reliable evidence of effectiveness. If you are looking for a culinary herb, do not gather wild plants that resemble parsley.

Aethusa cynapium · Apiaceae · Whole plant (aerial parts), occasionally used in homeopathic preparations · Homeopathic dilutions; rarely as crude plant material (not recommended)

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

Fool's Parsley: dosing

There is no established safe medicinal dose of Fool's Parsley. The crude plant is poisonous and should not be taken at any amount.For homeopathic products, dosing follows the directions on the specific product label, but these are not standardized medical doses and are not supported by strong evidence.

From our Fool's Parsley monograph — the full record covers uses, side effects and every documented interaction.

Read the full Fool's Parsley monograph & all interactions
Keep checking

Other Drugs & Fool's Parsley

Browse every other medication we’ve checked against Fool's Parsley — 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

Fool's Parsley References

The 1 references that drive our Fool's Parsley 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. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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 Fool's Parsley and Meperidine, Promethazine Together: Common Questions

Is it safe to take Fool's Parsley with Meperidine, Promethazine?
We do not list a known interaction between Fool's Parsley 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 — Fool's Parsley 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 Fool's Parsley?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.