Drug & supplement interaction

California Poppy + Hydroxyzine

Hydroxyzine brand names: Atarax, Vistaril, Ucerax.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between California Poppy and Hydroxyzine 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

California Poppy and Hydroxyzine

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 Hydroxyzine 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 Hydroxyzine and California Poppy? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Hydroxyzine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Hydroxyzine is filed under 5 classifications — including anticholinergic drugs, photosensitizing drugs, seizure threshold lowering drugs. California Poppy has documented interactions with 1 drug class — the most serious being cns depressants (moderate) — and none of Hydroxyzine’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 — Hydroxyzine 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. Hydroxyzine)

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

What California Poppy Itself Has Been Linked To

This is not an interaction — nothing below involves Hydroxyzine. It is the side-effect record for California Poppy on its own, from the licensed Natural Medicines monograph. If something new turns up after you add California Poppy, this list is the first place to look.

Joint or muscle stiffness Additional detail

“There is currently a limited amount of information available about the adverse effects of California poppy.

Most Common Adverse Effects:

Orally: When used in combination with hawthorn and magnesium, California poppy has been reported to cause muscular stiffness, morning fatigue, and nausea. It is not clear if these effects are from California poppy, the other ingredients, or the combination.”

California Poppy · Natural Medicines adverse-effect record, reported in fatigue.
Tiredness Additional detail
“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

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
Nausea Additional detail
“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

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

Everything above comes from the Natural Medicines adverse-effect record for California Poppy — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Hydroxyzine’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Hydroxyzine column appears here.

Overlapping uses

What Hydroxyzine Is Prescribed For, and What California Poppy Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Hydroxyzine is a prescription medicine with approved uses on its FDA label. California Poppy is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Hydroxyzine is prescribed for: Hydroxyzine is used to relieve anxiety and tension related to psychoneurosis (anxiety-based mental health conditions) and as a supportive treatment when anxiety is part of another medical condition. Oral forms — including tablets, capsules, and oral solution — are used for anxiety relief and to manage itching (pruritus) caused by allergic conditions such as chronic urticaria (hives), atopic dermatitis, contact dermatitis, and histamine-driven itch. Oral forms are also used as a sedative before and after surgery or general anesthesia. Hydroxyzine Hydrochloride intramuscular injection is used specifically when a shot is needed — for example, in acute psychiatric or emotional emergencies, acute alcohol withdrawal with anxiety symptoms or delirium tremens, control of nausea and vomiting (except during pregnancy), and as pre- and post-operative or pre- and post-partum supportive medication to reduce narcotic requirements and control nausea.

California Poppy has been studied for:

Anxiety studied, not established California Poppy has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

California Poppy for anxiety

Oral California poppy has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Hydroxyzine on your own; if you are taking California Poppy for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About California Poppy or Hydroxyzine

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 Hydroxyzine, 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 Hydroxyzine

This page covers California Poppy only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydroxyzine page lists 183 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Henbane (major), Scopolia (major) and St. John's Wort (major).

By severity: 5 major · 135 moderate · 43 minor.

From our pharmacist’s overview on the Hydroxyzine page

“Hydroxyzine (Atarax, Vistaril) is a sedating antihistamine for itching and anxiety, so read this list closely before pairing it with any supplement. Five of the 183 ingredients on file rate major, and those come first: grapefruit and St.”

Reviewed by 2 · Jul 18, 2026

Open the Hydroxyzine 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 Hydroxyzine, 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 Hydroxyzine 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

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

29 days ago today

Medication Hydroxyzine

Top 25%

#479 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 Hydroxyzine 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 Dr. Brian Staiger, PharmD, BCPS.

Supplement

About California Poppy

What is 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 Hydroxyzine

What Is Hydroxyzine Used For?

Brand names: Atarax, Vistaril, Ucerax

Hydroxyzine is used to relieve anxiety and tension related to psychoneurosis (anxiety-based mental health conditions) and as a supportive treatment when anxiety is part of another medical condition. Oral forms — including tablets, capsules, and oral solution — are used for anxiety relief and to manage itching (pruritus) caused by allergic conditions such as chronic urticaria (hives), atopic dermatitis, contact dermatitis, and histamine-driven itch. Oral forms are also used as a sedative before and after surgery or general anesthesia.

Hydroxyzine Hydrochloride intramuscular injection is used specifically when a shot is needed — for example, in acute psychiatric or emotional emergencies, acute alcohol withdrawal with anxiety symptoms or delirium tremens, control of nausea and vomiting (except during pregnancy), and as pre- and post-operative or pre- and post-partum supportive medication to reduce narcotic requirements and control nausea.

Most-Reported Side Effects for Hydroxyzine

From FAERS, the FDA’s public side-effect reporting system (50,845 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Pruritus 3,383 reports

Nausea 3,067 reports

Fatigue 2,961 reports

Toxicity to various agents 2,567 reports

Completed suicide 2,544 reports

See full Hydroxyzine 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 Hydroxyzine, 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.

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
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
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 Hydroxyzine Together: Common Questions

Is it safe to take California Poppy with Hydroxyzine?

We do not list a known interaction between California Poppy and Hydroxyzine. 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.

Are California Poppy and Hydroxyzine used for the same thing?

They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for California Poppy in each. That is a conversation for your prescriber, especially if Hydroxyzine is being adjusted to a target.

How was the California Poppy and Hydroxyzine combination checked?

Interactions in our licensed database are recorded against drug classes. Hydroxyzine is filed under 5 classifications, and California Poppy has documented interactions with 1 drug class — none of Hydroxyzine'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 — Hydroxyzine 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 Hydroxyzine interact with any supplements?

Yes. Hydroxyzine has documented interactions with 183 supplements in our database — California Poppy is not one of them. The Hydroxyzine 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 Hydroxyzine drug information The full plain-English guide to this medication Hydroxyzine supplement interactions Every supplement checked against Hydroxyzine, 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 Hydroxyzine 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.