Drug & supplement interaction

California Poppy + Thiotepa

Thiotepa brand names: Thioplex, Tepadina.

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 Thiotepa 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 Thiotepa

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 Thiotepa 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 Thiotepa and California Poppy? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Thiotepa

Interactions in our licensed database are recorded against drug classes, not just single drug names. Thiotepa is filed under 5 classifications — including alkylating agents, antineoplastics, cytochrome p450 2b6 (cyp2b6) substrates. California Poppy has documented interactions with 1 drug class — the most serious being cns depressants (moderate) — and none of Thiotepa’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 — Thiotepa 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. Thiotepa)
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 Thiotepa 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

    Thiotepa

    Listed in the ADVERSE REACTIONS section of the FDA label for Thiotepa. 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

    Thiotepa

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

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

Effects for Thiotepa come from the ADVERSE REACTIONS section of its FDA label; effects for California Poppy come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Everything else you take

See Every Supplement That Interacts With Thiotepa

This page covers California Poppy only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Thiotepa page lists 146 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Acerola (moderate).

By severity: 3 major · 102 moderate · 41 minor.

From our pharmacist’s overview on the Thiotepa page

“Thiotepa (Thioplex, Tepadina) is chemotherapy, given for several cancers and to prepare patients for stem cell transplant, so its 146 supplement interactions make up a list to respect rather than skim. Three carry a major rating: grapefruit, St.”

Reviewed by 2 · Jul 18, 2026

Open the Thiotepa 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 Thiotepa, 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 Thiotepa 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

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

29 days ago today
Medication Thiotepa
Steady interest

#2,099 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 Thiotepa 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 Thiotepa Injection

What Is Thiotepa Injection Used For?

Brand names: Thioplex, Tepadina

Tepadina (thiotepa) injection is used for several purposes. It treats adenocarcinoma (a type of cancer) of the breast or ovary. It is also used to control malignant effusions — abnormal fluid buildup in body cavities caused by cancer spreading to those areas. For bladder cancer, Tepadina treats superficial papillary carcinoma of the urinary bladder.

Tepadina is also used in pediatric patients with class 3 beta-thalassemia (a severe inherited blood disorder). In those patients, it is given as part of a preparative regimen — a conditioning treatment to reduce the risk of graft rejection before an allogeneic stem cell transplant (a transplant using donor stem cells), alongside the chemotherapy drugs busulfan and cyclophosphamide.

Most-Reported Side Effects for Thiotepa

From FAERS, the FDA’s public side-effect reporting system (9,494 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Febrile neutropenia 814 reports
Mucosal inflammation 807 reports
Cytomegalovirus infection 533 reports
Fever 516 reports
Acute graft versus host disease 458 reports
See full Thiotepa Injection 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 Thiotepa, 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 Thiotepa Together: Common Questions

Is it safe to take California Poppy with Thiotepa?
We do not list a known interaction between California Poppy and Thiotepa. 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 Thiotepa 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 Thiotepa combination checked?
Interactions in our licensed database are recorded against drug classes. Thiotepa is filed under 5 classifications, and California Poppy has documented interactions with 1 drug class — none of Thiotepa'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 — Thiotepa 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 Thiotepa interact with any supplements?
Yes. Thiotepa has documented interactions with 146 supplements in our database — California Poppy is not one of them. The Thiotepa 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 Thiotepa Injection drug information The full plain-English guide to this medication Thiotepa supplement interactions Every supplement checked against Thiotepa, 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 Thiotepa and California Poppy?

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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.