Drug & supplement interaction

California Poppy + Finasteride

Finasteride brand names: Propecia, Proscar.

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 Finasteride 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 Finasteride

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

Why No Interaction Is Listed for Finasteride

Interactions in our licensed database are recorded against drug classes, not just single drug names. Finasteride is filed under 3 classifications — including cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. California Poppy has documented interactions with 1 drug class — the most serious being cns depressants (moderate) — and none of Finasteride’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 — Finasteride 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. Finasteride)
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 Finasteride May Share a Side Effect

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

    Finasteride

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

Reported for California Poppy but not commonly for Finasteride: joint or muscle stiffness and nausea.

Effects for Finasteride 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.

From our Q&A

Questions About California Poppy or Finasteride

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 Finasteride, 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 Finasteride

This page covers California Poppy only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Finasteride page lists 138 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 Adrafinil (moderate).

By severity: 3 major · 94 moderate · 41 minor.

From our pharmacist’s overview on the Finasteride page

“The supplement list for finasteride (Propecia, Proscar) is one I would read carefully rather than skim, because three of its 138 entries are rated major. Almost everything here works through the same liver enzyme, CYP3A4, that clears finasteride.”

Reviewed by 2 · Jul 18, 2026

Open the Finasteride 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 Finasteride, 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 Finasteride 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

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

29 days ago today
Medication Finasteride
Top 5%

#62 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 Finasteride 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 Finasteride

What Is Finasteride Used For?

Brand names: Propecia, Proscar

Finasteride tablets (including the brand Proscar) are used in men with an enlarged prostate (benign prostatic hyperplasia, or BPH) to improve urinary symptoms, lower the risk of acute urinary retention (a sudden inability to urinate), and reduce the need for prostate surgery. Finasteride tablets may also be used alongside the alpha-blocker doxazosin to slow the progression of BPH symptoms.

Propecia (and finasteride 1 mg coated tablets) is indicated for the treatment of male pattern hair loss (androgenetic alopecia) in men only. Propecia is not approved for use in women, and its effectiveness for hair loss at the temples has not been established. Finasteride is not approved for the prevention of prostate cancer.

See full Finasteride 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 Finasteride, 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 Finasteride Together: Common Questions

Is it safe to take California Poppy with Finasteride?
We do not list a known interaction between California Poppy and Finasteride. 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 Finasteride have any of the same side effects?
Yes — our sources link each of them separately to one 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 Finasteride combination checked?
Interactions in our licensed database are recorded against drug classes. Finasteride is filed under 3 classifications, and California Poppy has documented interactions with 1 drug class — none of Finasteride'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 — Finasteride 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 Finasteride interact with any supplements?
Yes. Finasteride has documented interactions with 138 supplements in our database — California Poppy is not one of them. The Finasteride 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 Finasteride drug information The full plain-English guide to this medication Finasteride supplement interactions Every supplement checked against Finasteride, 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 Finasteride 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.