Drug & supplement interaction

California Poppy + Vancomycin

Vancomycin brand names: Vancocin, Vancoled.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between California Poppy and Vancomycin 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

California Poppy and Vancomycin

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 Vancomycin and California Poppy 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.

California Poppy safety at a glance

California Poppy overall Use caution Generally considered mild for short-term use, but human safety data are limited.
Pregnancy Avoid Not enough safety data; best avoided during pregnancy.
Breastfeeding Avoid Not enough safety data; best avoided while breastfeeding.

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

Still wondering about combining Vancomycin and California Poppy? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Vancomycin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Vancomycin is filed under 2 classifications — antibiotic drugs, oral drugs. California Poppy has documented interactions with 1 drug class — the most serious being cns depressants (moderate) — and none of Vancomycin’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

California Poppy Does Interact With Other Medications

California Poppy has 248 moderate known drug interactions in our database — Vancomycin isn’t one of them. If you take anything else, check it against the full list below.

Moderate 248 No known interaction 2,582 (incl. Vancomycin)
Taking anything else?

Check Another of Your Medications Against California Poppy

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

What to actually watch for

No Interaction Found — But Data Suggests California Poppy and Vancomycin May Share Several of the Same Side Effects

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.

  • Tiredness Additional detail

    California Poppy

    “Orally, when used in combination with hawthorn and magnesium, California poppy has been reported to cause morning fatigue. It is not clear if this effect is from California poppy, the other ingredients, or the combination.”

    California Poppy · Natural Medicines adverse-effect record, reported in fatigue.

    1 source cited
    1. 12583. Hanus M, Lafon J, Mathieu M. Double-blind, randomised, placebo-controlled study to evaluate the efficacy and safety of a fixed combination containing two plant extracts (Crataegus oxyacantha and Eschscholtzia californica) and magnesium in mild-to-moderate

    Vancomycin

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

  • Nausea Additional detail

    California Poppy

    “Orally, when used in combination with hawthorn and magnesium, California poppy has been reported to cause nausea. It is not clear if this effect is from California poppy, the other ingredients, or the combination.”

    California Poppy · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    1 source cited
    1. 12583. Hanus M, Lafon J, Mathieu M. Double-blind, randomised, placebo-controlled study to evaluate the efficacy and safety of a fixed combination containing two plant extracts (Crataegus oxyacantha and Eschscholtzia californica) and magnesium in mild-to-moderate

    Vancomycin

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

Reported for California Poppy but not commonly for Vancomycin: joint or muscle stiffness.

Effects for Vancomycin come from the ADVERSE REACTIONS section of its FDA label; effects for California Poppy come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 64,480 voluntary FDA FAERS reports for Vancomycin 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 California Poppy or Vancomycin

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

This page covers California Poppy only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Vancomycin page lists 44 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Bacillus Coagulans (moderate), Bacillus Subtilis (moderate), Bifidobacterium Animalis Subsp. Lactis (moderate) and Bifidobacterium Bifidum (moderate).

By severity: 1 major · 33 moderate · 10 minor.

From our pharmacist’s overview on the Vancomycin page

“Vancomycin (Vancocin) treats serious bacterial infections, and its oral form is a mainstay for C. diff in the gut, so read this list as a genuine safety check, not background noise.”

Reviewed by 2 · Jul 18, 2026

Open the Vancomycin interaction page

One more smart check

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

We hold 345 real supplement products containing California Poppy, each one broken down to its full ingredient list — and combination products often carry several ingredients besides California Poppy. Even though California Poppy itself has no known interaction with Vancomycin, 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 California Poppy and Vancomycin 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 California Poppy
Top half

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

29 days ago today
Medication Vancomycin
Top 25%

#342 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 California Poppy reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The California Poppy and Vancomycin 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 California Poppy

What is California Poppy?

California Poppy
  • Anxiety and stress
  • Trouble sleeping (insomnia)
  • Mild aches and pains
  • Restlessness or nervous tension
  • Bedwetting in children (traditional use)

California poppy is a traditional herbal remedy used mainly for anxiety and sleep problems, often combined with other calming herbs. Human research is very limited, so its true benefits are not well proven. It is generally considered mild, but should be avoided during pregnancy and breastfeeding and used with caution by anyone taking sedating medicines.

Eschscholzia californica · Papaveraceae · Above-ground parts (flowers, leaves, stems) and roots · Tea, tincture, liquid extract, capsules, dried herb

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

California Poppy: dosing

There is no official, standardized dose for California poppy. Products vary widely in strength, and it is often part of herbal blends. The best approach is to follow the directions on the product label and not exceed the recommended amount.It is commonly taken in the evening when used for sleep, but timing and amount should be guided by the product and your own response.

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

Read the full California Poppy monograph & all interactions
Medication

About Vancomycin

What Is Vancomycin Used For?

Brand names: Vancocin, Vancoled

Vancomycin is used to fight serious bacterial infections caused by certain hard-to-treat bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). When given intravenously (by IV), it treats conditions like septicemia (a serious bloodstream infection), infective endocarditis (infection of the heart valves), skin and skin structure infections, bone infections, and lower respiratory tract infections.

When taken by mouth — as capsules or oral solution (brands include Vancocin and Firvanq) — vancomycin treats Clostridioides difficile-associated diarrhea (C. diff) and staphylococcal enterocolitis (a gut infection caused by Staphylococcus aureus). It's important to know that the oral form does not work for bloodstream or other serious infections, and the IV form does not work for C. diff or gut infections — each route has its own specific uses.

Most-Reported Side Effects for Vancomycin

From FAERS, the FDA’s public side-effect reporting system (65,520 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Acute kidney injury 4,892 reports
Fever 4,046 reports
Drug reaction with eosinophilia and systemic symptoms 2,695 reports
Renal failure 2,468 reports
Diarrhea 2,392 reports
See full Vancomycin drug information
Keep checking

Other Drugs & California Poppy

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

0Major
248Moderate
0Minor
2,581No known interaction
248 Moderate 2,581 No interaction
Moderate

248 interactions

Showing 60 of 248 moderate interactions — see all 248 on the California Poppy page.

No interaction 2,581 drugs checked — show the list

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

Showing the 60 most looked-up of 2,581 medications checked with no known interaction — see the full California Poppy list.

See the full California Poppy interactions page
See every supplement checked against Vancomycin, ranked by severity
Evidence & sources

California Poppy References

The 3 references that drive our California Poppy 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. Hanus M, Lafon J, Mathieu M. Double-blind, randomised, placebo-controlled study to evaluate the efficacy and safety of a fixed combination containing two plant extracts (Crataegus oxyacantha and Eschscholtzia californica) and magnesium in mild-to-moderate
  2. Paul LD, Springer D, Staack RF, et al. Cytochrome P450 isoenzymes involved in rat liver microsomal metabolism of californine and protopine. Eur J Pharmacol 2004;485:69-79. PubMed
  3. Paul LD, Maurer HH. Studies on the metabolism and toxicological detection of the Eschscholtzia californica alkaloids californine and protopine in urine using gas chromatography-mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2003;789:43-5

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 California Poppy and Vancomycin Together: Common Questions

Is it safe to take California Poppy with Vancomycin?
We do not list a known interaction between California Poppy and Vancomycin. 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 California Poppy and Vancomycin have any of the same side effects?
Yes — our sources link each of them separately to 2 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 California Poppy and Vancomycin combination checked?
Interactions in our licensed database are recorded against drug classes. Vancomycin is filed under 2 classifications, and California Poppy has documented interactions with 1 drug class — none of Vancomycin'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 California Poppy interact with any other medications?
Yes. California Poppy has 248 documented drug interactions in our database — Vancomycin 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 Vancomycin interact with any supplements?
Yes. Vancomycin has documented interactions with 44 supplements in our database — California Poppy is not one of them. The Vancomycin 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

California Poppy monograph Uses, safety profile, and every drug interaction in one place Vancomycin drug information The full plain-English guide to this medication Vancomycin supplement interactions Every supplement checked against Vancomycin, 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Vancomycin and California Poppy?

Our pharmacists answer your medication & supplement questions — free.

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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.