California Poppy
Summary
California poppy (Eschscholzia californica) is a traditional sedative herb. No controlled trial has tested it alone for anxiety or sleep. A 264-person trial of a hawthorn, California poppy and magnesium tablet modestly reduced anxiety (grade C), and an uncontrolled sleep study used a blend with melatonin. Lab studies show possible drug-metabolism interactions.
Key facts
- No outcome trial found; the only single-herb human data are a 1998 EEG screen of single doses in healthy women, whose abstract does not report results per extract[7][1][2]
- A hawthorn, California poppy and magnesium tablet cut Hamilton anxiety scores 1.7 points more than placebo over 3 months in 264 adults[1]
- Californidine, escholtzine and protopine; contents varied roughly 12- to 25-fold across eight commercial products[6]
- Ethanol extract and alkaloids inhibited CYP3A4, 2C9, 2C19 and 2D6 in vitro; the water extract (tea) did not[5]
- Aqueous extract was sedative above 100 mg/kg and anxiolytic at 25 mg/kg in mice[3]
- 2 graded human outcomes on this page
- October 13, 2026
How it works
ProposedIn mice, aqueous extract reduced activity and induced sleep at higher doses and had anxiolytic-like effects at lower doses. Reviews of preclinical work point to GABA-related mechanisms for this group of plants. In lab tests, its alkaloids inhibited several CYP enzymes; none of this has been confirmed in people.[3][4][5]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Anxiety | Grade C | Improved | RCT · n = 264 · 2004 | 1 row |
| Sleep | Grade D | Improved | Open-label · n = 40 · 2019 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Anxiety scores in mild-to-moderate generalized anxiety (combination) | Improved | Grade C | RCT · n = 264 · 2004 Adults with mild-to-moderate generalized anxiety in general practice, 81% women (France) Form: Combination tablet: hawthorn and California poppy extracts with magnesium (Sympathyl) · Dose: Two tablets twice daily · Duration: 3 months Hamilton anxiety scores fell 10.6 points vs 8.9 with placebo (P=0.005) and self-rated anxiety improved more (P=0.005). Adverse events: 11.5% vs 9.7%, mostly mild digestive or psychological. | 14741074 (opens PubMed)Source [1] |
| Sleep quality and sleep onset in mild-to-moderate insomnia (combination) | Improved | Grade D | Open-label trial · n = 40 · 2019 Adults with mild-to-moderate insomnia (Poland) Form: Combination capsule: melatonin, vitamin B6, California poppy, passionflower and lemon balm extracts · Dose: Daily capsules (California poppy amount not stated in the abstract) · Duration: 2 weeks Sleep-diary quality rose from 5.4 to 7.3 out of 10 (P<0.001), with shorter sleep onset and longer sleep. No serious adverse events. | 31331545 (opens PubMed)Source [2] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| California poppy extract (ethanol or hydroalcoholic) | Varies[6] | In a Caco-2 cell model, escholtzine and protopine were highly permeable and californidine low-to-moderately permeable; no human absorption data.[6] | No tolerance data from single-herb outcome trials; in the combination anxiety trial, adverse events were similar to placebo (11.5% vs 9.7%).[1] | Combination anxiety and sleep products |
| California poppy tea (aqueous extract) | Varies[5] | No human absorption data.[5] | No human tolerance data; in lab tests the tea did not affect CYP enzymes, P-gp or PXR, unlike the ethanol extract.[5] | Traditional use; mouse behaviour studies |
Studied doses
Doses studied in human trials ranged from daily capsules of a melatonin-herb blend for 2 weeks to two tablets twice daily of a hawthorn, California poppy and magnesium product for 3 months. No trial reports a dose of California poppy alone.[1][2]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- People on prescription medicines
- In lab tests, the ethanol extract and its alkaloids inhibited CYP3A4, CYP2C9, CYP2C19 and CYP2D6, enzymes that clear many drugs; this has not been tested in people.[5]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
- Check whether it is a blendBoth human studies used combination products (with hawthorn and magnesium, or with melatonin and other herbs), so results cannot be credited to California poppy.[1][2]
- Label dose vs studied doseNeither study abstract states how much California poppy each tablet or capsule held, so no studied dose of the herb itself exists to compare with a label.[1][2]
- Alkaloid content variesEight commercial products differed widely in californidine (0.13–2.55 mg/g) and escholtzine (0.05–0.63 mg/g).[6]
Frequently asked questions
Does California poppy help with sleep?
No sleep trial has tested it alone. An uncontrolled 2-week study of a blend containing melatonin and California poppy reported better sleep-diary scores.[2]
Does California poppy reduce anxiety?
A 264-person trial of a tablet combining hawthorn, California poppy and magnesium modestly lowered anxiety scores more than placebo over 3 months.[1]
Is California poppy the same as the opium poppy?
No. California poppy (Eschscholzia californica) has its own alkaloids, mainly californidine, escholtzine and protopine.[6]
Does California poppy interact with medications?
Possibly. In lab tests its ethanol extract inhibited several drug-metabolizing CYP enzymes, while the tea did not; no human interaction study exists.[5]
How strong are California poppy products?
It varies. Eight commercial products differed roughly 20-fold in their main alkaloid, californidine.[6]
Sources
- [1]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 anxiety disorders.. Curr Med Res Opin, 2004. RCT
- [2]A combination of melatonin, vitamin B6 and medicinal plants in the treatment of mild-to-moderate insomnia: A prospective pilot study.. Complement Ther Med, 2019. open-label
- [3]Behavioural effects of the American traditional plant Eschscholzia californica: sedative and anxiolytic properties.. Planta Med, 1991. animal-study
- [4]Plant-based medicines for anxiety disorders, Part 1: a review of preclinical studies.. CNS Drugs, 2013. review
- [5]Modulation of CYPs, P-gp, and PXR by Eschscholzia californica (California Poppy) and Its Alkaloids.. Planta Med, 2016. animal-study
- [6]Alkaloids in commercial preparations of California poppy - Quantification, intestinal permeability and microbiota interactions.. Biomed Pharmacother, 2023. animal-study
- [7]The quantitative EEG as a screening instrument to identify sedative effects of single doses of plant extracts in comparison with diazepam.. Phytomedicine, 1998. crossover-RCT
What changed
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for the cited rows. No outcome trial of California poppy alone was found in PubMed (a 1998 placebo-controlled EEG screening study included a single-dose arm, but its abstract gives no per-extract result, so it is not an evidence row); the 2013 preclinical review lists it among plants with only preclinical anxiolytic evidence at that time. Manda 2016 (in vitro) and Chauveau 2023 (cell and gut-model study, erratum noted) are typed as non-human studies and cited for mechanism, safety caution and product variation only. Page set indexable.