Drug & supplement interaction

Corydalis Yanhusuo + Meperidine, Promethazine

Meperidine, Promethazine brand names: Meprozine, Mepergan.

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

Meperidine, Promethazine falls into 2 drug categories that Corydalis Yanhusuo can interact with; the most serious is rated moderate. Theoretically, Corydalis yanhusuo might increase the sedative effects of CNS depressants.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Corydalis Yanhusuo and Meperidine, Promethazine

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Corydalis Yanhusuo interacts with whole categories of medication. Meperidine, Promethazine falls into 2 of those categories, so it can interact with Corydalis Yanhusuo in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CNS DEPRESSANTS

1 of 2

Why this applies to Meperidine, Promethazine

Meperidine, Promethazine falls under CNS DEPRESSANTS — the group Corydalis Yanhusuo interacts with.

Theoretically, Corydalis yanhusuo might increase the sedative effects of CNS depressants.
Corydalis yanhusuo contains berberine. Animal research suggests that berberine may have sedative effects. Theoretically, Corydalis yanhusuo might also have CNS depressants effects.
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 thing to know about combining Corydalis with Meprozine or Mepergan (a combo of meperidine, an opioid pain reliever, and promethazine, a sedating antihistamine). Both ingredients in your medicine already slow down the brain and nervous system. Corydalis contains natural compounds that, at least in lab and animal studies, also seem to have a calming, sedating effect. So stacking them could add up.

What might that look like in real life? More drowsiness, dizziness, foggy thinking, slowed breathing, or feeling unsteady on your feet. I'll be honest, this concern is theoretical and based mostly on how these things work, not solid human studies. Still, it's worth running past your pharmacist or doctor before you mix them, especially since opioids deserve extra caution.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Janbaz KH, Gilani AH. Studies on preventive and curative effects of berberine on chemical-induced hepatotoxicity in rodents. Fitoterapia 2000;71:25-33.. PubMed
  2. Shanbhag, S. M., Kulkarni, H. J., and Gaitonde, B. B. Pharmacological actions of berberine on the central nervous system. Jpn.J Pharmacol 1970;20(4):482-487. PubMed
  3. Peng, W. H., Hsieh, M. T., and Wu, C. R. Effect of long-term administration of berberine on scopolamine-induced amnesia in rats. Jpn J Pharmacol 1997;74(3):261-266. DOI
  4. Sabir M and Bhide NK. Study of some pharmacological actions of berberine. Ind J Physiol & Pharmac 1971;15(3):111-132.
Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

2 of 2

Meperidine, Promethazine also falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES.

Theoretically, Corydalis yanhusuo might increase serum levels of drugs metabolized by CYP2D6.
Corydalis yanhusuo contains berberine. In vitro research and preliminary clinical evidence show that berberine can inhibit CYP2D6. Theoretically, Corydalis yanhusuo might also inhibit CYP2D6.
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

This combo product pairs meperidine (a strong opioid painkiller) with promethazine (an antihistamine that calms nausea and adds drowsiness). Both rely partly on an enzyme called CYP2D6 to be processed. Corydalis contains berberine, which lab and early human data suggest may slow that enzyme down. In theory, if your body clears these drugs more slowly, they could build up and hit harder.

What that might look like in real life: extra sleepiness, dizziness, slowed breathing, confusion, or low blood pressure. One wrinkle with meperidine is that it can lower the seizure threshold, so higher levels are something to take seriously. Keep in mind this is a theoretical concern based on pharmacology, not proven harm. Still, please check with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Chatterjee P, Franklin MR. Human cytochrome p450 inhibition and metabolic-intermediate complex formation by goldenseal extract and its methylenedioxyphenyl components. Drug Metab Dispos 2003;31:1391-7. PubMed
  2. Guo, Y., Chen, Y., Tan, Z. R., Klaassen, C. D., and Zhou, H. H. Repeated administration of berberine inhibits cytochromes P450 in humans. Eur J Clin Pharmacol 2012;68(2):213-217. PubMed
  3. Hermann, R. and von, Richter O. Clinical evidence of herbal drugs as perpetrators of pharmacokinetic drug interactions. Planta Med 2012;78(13):1458-1477. 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

Corydalis Yanhusuo Also Interacts With Other Medications

Corydalis Yanhusuo has 1,159 moderate known drug interactions in our database — the Meperidine, Promethazine one above is among them. If you take anything else, check it against the full list below.

Moderate 1,159 No known interaction 1,671 (incl. Meperidine, Promethazine)
Taking anything else?

Check Another of Your Medications Against Corydalis Yanhusuo

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

Everything else you take

See Every Supplement That Interacts With Meperidine, Promethazine

This page covers Corydalis Yanhusuo 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 Corydalis Yanhusuo 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 Corydalis Yanhusuo
Steady interest

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

29 days ago today
Medication Meperidine, Promethazine
Top 25%

#355 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 Corydalis Yanhusuo

What is Corydalis Yanhusuo?

  • Pain relief
  • Menstrual cramps
  • Headache
  • Stress and sleep support
  • Stomach and abdominal discomfort

Corydalis yanhusuo is a traditional Chinese herb used mainly for pain. Some early laboratory and animal research suggests its compounds may affect pain and the nervous system, but high-quality human studies are limited, so its true benefits and long-term safety are not well established. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Corydalis Yanhusuo monograph & all interactions
Keep checking

Other Drugs & Corydalis Yanhusuo

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

0Major
1,159Moderate
0Minor
1,670No known interaction
1,159 Moderate 1,670 No interaction
Moderate

1,159 interactions

Showing 60 of 1,159 moderate interactions — see all 1,159 on the Corydalis Yanhusuo page.

No interaction 1,670 drugs checked — show the list

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

Showing the 60 most looked-up of 1,670 medications checked with no known interaction — see the full Corydalis Yanhusuo list.

See the full Corydalis Yanhusuo interactions page
See every supplement checked against Meperidine, Promethazine, 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
Corydalis Yanhusuo monograph › Uses, safety, and every drug interaction in one place Meperidine, Promethazine supplement interactions › Every supplement checked against Meperidine, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Corydalis Yanhusuo and Meperidine, Promethazine Together: Common Questions

Can you take Corydalis Yanhusuo with Meperidine, Promethazine?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Corydalis Yanhusuo and Meperidine, Promethazine?
Meperidine, Promethazine belongs to more than one drug category, and Corydalis Yanhusuo 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 Corydalis Yanhusuo and Meperidine, Promethazine interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

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