Plant Comparison

California Poppy vs Wild Lettuce

A side-by-side comparison of two medicinal plants — every documented constituent, action, use, safety note and cited source, assembled automatically from the Omnia Sana database.

First plant
Second plant
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Plant ACalifornia PoppyEschscholzia californicaPapaveraceaeFull monograph →
Plant BWild LettuceLactuca virosaAsteraceaeFull monograph →

At a glance

California Poppy and Wild Lettuce: they share 7 indicated uses (anxiety, back pain, headache, …); 3 pharmacological actions in common.

California PoppyWild Lettuce
Constituents12
Pharmacological actions34
Indicated uses78
Safety notes22
Cited sources1414
Indicated uses
Only California Poppy
none
Shared (7)
AnxietyBack painHeadacheInsomnia / sleeplessnessNervous tensionPain (general)Stress
Only Wild Lettuce
Cough
Pharmacological actions
Only California Poppy
none
Shared (3)
Analgesic (pain relief)Anxiolytic / calmingSedative / sleep support
Only Wild Lettuce
Antitussive (cough suppressant)

Evidence face-off — shared uses

ConditionCalifornia PoppyWild LettuceVerdict
Anxiety5/101/10Stronger for California Poppy
Back pain2/102/10Comparable evidence
Headache2/102/10Comparable evidence
Insomnia / sleeplessness2/102/10Comparable evidence
Nervous tension5/101/10Stronger for California Poppy
Pain (general)2/102/10Comparable evidence
Stress5/101/10Stronger for California Poppy

Evidence scores (1–10) are computed from the tier of each cited source. “Comparable” means the two scores are within one point. Follow a score to its detailed sources.

Key Constituents

Isoquinoline alkaloids (protopine, allocryptopine, californidine, escholtzine, (S)-reticuline)[3, 4, 5, 6, 7, 8, 9]

(S)-reticuline modulates GABA-A receptor chloride currents, underlying the calming effect.

Alkaloids
Sesquiterpene lactones (lactucin, lactucopicrin)[4, 11, 12]

Bitter, centrally-active constituents responsible for the sedative and pain-relieving effects; isolated lactucin and lactucopicrin produced analgesia comparable to ibuprofen and sedation in rodent tests.

Sesquiterpene lactonesSesquiterpenes
Lactucarium (the dried milky latex)[11]

The historical medicinal preparation, concentrating the active lactones.

Pharmacological Actions

Analgesic (pain relief)[2, 7]

Mild analgesic (traditional use for pain)

Anxiolytic / calming[1, 2, 4, 7, 10]

Anxiolytic for anxiety and nervous tension - also supported by a double-blind RCT of a fixed California poppy + hawthorn (Crataegus) + magnesium combination in mild-to-moderate anxiety

Sedative / sleep support[1, 2, 7]

Mild sedative / sleep support for insomnia (positive allosteric modulation of GABA-A receptors)

Analgesic (pain relief)[4, 6, 11, 12]

Mild analgesic / anodyne for pain (lactucin and lactucopicrin act on the central nervous system) - in mice these compounds produced analgesia comparable to ibuprofen

Antitussive (cough suppressant)[5, 11]

Antitussive for an irritable, dry cough (traditional)

Anxiolytic / calming[11]

Calming for nervous tension and restlessness

Sedative / sleep support[4, 6, 7, 8, 11]

Sedative for sleeplessness / insomnia - lactucin and lactucopicrin showed sedative activity in animal models

Traditional & Indicated Uses

Anxiety[7, 10]Moderate · 5/10

Anxiolytic for anxiety and nervous tension - also supported by a double-blind RCT of a fixed California poppy + hawthorn (Crataegus) + magnesium combination in mild-to-moderate anxiety

Evidence: 5
Label: Anxiety
Back pain[7]Traditional · 2/10

inferred from analgesic action

Evidence: 2
Label: Back pain
Headache[7]Traditional · 2/10

inferred from analgesic action

Evidence: 2
Label: Headache
Insomnia / sleeplessness[7]Traditional · 2/10

Mild sedative / sleep support for insomnia (positive allosteric modulation of GABA-A receptors)

Evidence: 2
Label: Insomnia / sleeplessness
Nervous tension[7, 10]Moderate · 5/10

Anxiolytic for anxiety and nervous tension - also supported by a double-blind RCT of a fixed California poppy + hawthorn (Crataegus) + magnesium combination in mild-to-moderate anxiety

Evidence: 5
Label: Nervous tension
Pain (general)[7]Traditional · 2/10

Mild analgesic (traditional use for pain)

Evidence: 2
Label: Pain (general)
Stress[7, 10]Moderate · 5/10

inferred from anxiolytic action

Evidence: 5
Label: Stress
Anxiety[11]Traditional · 1/10

inferred from anxiolytic action

Evidence: 1
Label: Anxiety
Back pain[4, 11, 12]Traditional · 2/10

inferred from analgesic action

Evidence: 2
Label: Back pain
Cough[11]Traditional · 1/10

Antitussive for an irritable, dry cough (traditional)

Evidence: 1
Label: Cough
Headache[4, 11, 12]Traditional · 2/10

inferred from analgesic action

Evidence: 2
Label: Headache
Insomnia / sleeplessness[4, 11]Traditional · 2/10

Sedative for sleeplessness / insomnia - lactucin and lactucopicrin showed sedative activity in animal models

Evidence: 2
Label: Insomnia / sleeplessness
Nervous tension[11]Traditional · 1/10

Calming for nervous tension and restlessness

Evidence: 1
Label: Nervous tension
Pain (general)[4, 11, 12]Traditional · 2/10

Mild analgesic / anodyne for pain (lactucin and lactucopicrin act on the central nervous system) - in mice these compounds produced analgesia comparable to ibuprofen

Evidence: 2
Label: Pain (general)
Stress[11]Traditional · 1/10

inferred from anxiolytic action

Evidence: 1
Label: Stress

Safety, Cautions & Contraindications

Safety note[7]Caution

Has sedative activity: it can add to the effects of alcohol, sedatives and sleep medicines, so avoid combining and do not use before driving.

Safety note[9]Caution

Alcoholic (ethanol) extracts inhibit or induce several cytochrome P450 enzymes (CYP3A4, 2C9, 2C19, 2D6) and activate the pregnane X receptor, so there is a risk of herb-drug interactions; the water-based tea appears safer in this respect. Avoid in pregnancy and breastfeeding.

Safety note[12]Info

Can be unsafe in large amounts or if harvested too early: overdose can cause sweating, fast heartbeat, dilated pupils, dizziness, ringing in the ears, vision changes, heavy sedation, breathing difficulty and, in extreme cases, death.

Safety note[11, 12]Caution

Its sedative effect can add to that of sedatives and alcohol - avoid combining and do not use before driving. As a daisy-family (Asteraceae) plant it can cause allergy; avoid in pregnancy and breastfeeding.

External Ids

Gbif: 2888380
Wikidata: Q158795
Gbif: 3140346
Wikidata: Q578927

Botanical Description

Herbaceous perennial (often grown as an annual) with delicate, finely divided, blue-green feathery foliage. Solitary, cup-shaped, four-petalled flowers in vivid orange to yellow arise on long stalks, opening in full sun and closing at night or in dull weather, followed by a long, slender, ridged seed capsule that splits explosively when ripe.[7]

Height: 20-60 cm
Habit: Herbaceous perennial, often grown as an annual
Leaves: Finely divided, blue-green, feathery
Flowers: Solitary, cup-shaped, four-petalled, vivid orange to yellow, opening in sun and closing at night
Stem: Slender, branching, blue-green
Root: Deep taproot
Fruit: Long, slender, ridged seed capsule, dehiscing explosively when ripe
Flowering Period: Spring to autumn

Tall, bristly biennial herb with a milky latex throughout, and prickly-edged, often blue-green leaves that tend to twist to align edge-on with the sun ('compass plant' habit). Small, pale yellow, dandelion-like flower heads are borne in loose branched clusters atop a tall, spiny-stemmed flowering stalk.[11]

Height: 1-2 m
Habit: Tall, bristly biennial herb; low rosette in year one, tall flowering stem in year two
Leaves: Prickly-edged, often blue-green, sometimes twisting edge-on to the sun
Flowers: Small, pale yellow, dandelion-like flower heads in loose branched clusters
Stem: Tall, spiny, exuding milky white latex when cut
Root: Taproot
Fruit: Small achene with a feathery pappus
Flowering Period: July-September (second year)

Habitat

Native to open grassland, coastal scrub and disturbed ground of California and neighbouring states; widely cultivated and naturalised elsewhere as a garden ornamental.[7]

Grows on dry waste ground, roadsides, hedgerows and disturbed soil; native to Europe, North Africa and Western Asia and naturalised in North America.

Harvesting

The flowering aerial parts are cut in summer while in flower, and dried in a warm, shaded, airy place.[7]

Parts: Aerial parts (flowering herb)
Season: Summer, at flowering

The milky latex is traditionally collected by scoring the flowering stem and letting the exuded sap dry into lactucarium; the aerial parts (leaf and stem) are also cut and dried while the plant is flowering.[11]

Parts: Aerial parts and dried latex (lactucarium)
Season: Flowering (second year); latex collected by scoring the stem

Traditional Uses

California poppy has a Native American traditional reputation as a mild calming and pain-relieving remedy, used for insomnia, nervous tension and mild pain; unlike the related opium poppy it is non-addictive and its calming effects are now attributed to GABA-A receptor modulation, supporting its traditional anxiolytic and sedative use.[7]

Wild lettuce has a long folk history, reflected in the name 'opium lettuce', as a mild sedative and analgesic remedy for insomnia, nervous tension and pain, and as an antitussive for irritable dry cough, its dried latex (lactucarium) once used as a milder, non-addictive alternative to opium.[11]

Preparations

Infusion[7]

Dried flowering herb infused in hot water as a traditional calming, sleep-supporting tea.

Tincture[9]

Alcoholic extract of the dried flowering herb; note that alcoholic extracts (unlike the water-based tea) can affect drug-metabolising liver enzymes.

Standardised extract[10]

Concentrated extract, sometimes combined with hawthorn and magnesium, studied in a clinical trial for mild-to-moderate anxiety.

Infusion[11]

Dried aerial parts infused in hot water as a traditional calming, sleep-supporting tea.

Lactucarium (historical)[12]

Dried milky latex, the classic historical preparation, used cautiously given its overdose toxicity.

Dosage

Powdered herbal substance[11]

The EU herbal monograph gives a single dose of 480-600 mg of the powdered herb and a daily dose of 960-1500 mg, in adults and elderly; for sleep, one single dose with dinner and another 30-60 minutes before bedtime. Not recommended under 18 years; consult a practitioner if symptoms persist beyond 2 weeks. Educational reference only, not a prescription.

Infusion[12]

Health Canada's NNHPD monograph gives 0.2-3 g of dried flowering herb top per day for adults 18 years and older, with infusion among the accepted methods of preparation. The EU herbal monograph covers the powdered herbal substance only and gives no infusion posology. Educational reference only, not a prescription.

Infusion[12]

Because of documented overdose toxicity (rapid heartbeat, heavy sedation, breathing difficulty), only conservative traditional herbal doses should be used and this herb should not be self-dosed at concentrated or extract strength without professional guidance. Educational reference only, not a prescription.

References

REF-0806, REF-0807, REF-0808, REF-2305, REF-2306, REF-2307, REF-0427, REF-2316
REF-0854, REF-0855, REF-0856, REF-0622, REF-2059, REF-2060, REF-2061, REF-2062, REF-2063, REF-2064

Drug Class Interactions

Safety note[13, 14]Caution
Drug Class: sedatives-cns-depressants
Mechanism: California poppy has calming, sedative effects; taken with sedatives, sleeping tablets or other central-nervous-system depressants (including alcohol) it may add to drowsiness and slowed reactions.
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-03
Safety note[13, 14]Caution
Drug Class: sedatives-cns-depressants
Mechanism: Wild lettuce is traditionally used as a calming, sedative herb; taken with sedatives, sleeping tablets or other central-nervous-system depressants (including alcohol) it may add to drowsiness and slowed reactions.
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-03

Lookalikes Review

Outcome: none-known
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07
Outcome: none-known
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07

References & Sources

  1. Rolland, A., Fleurentin, J., Lanhers, M.C., Younos, C. et al (1991) 'Behavioural effects of the American traditional plant Eschscholzia californica: sedative and anxiolytic properties', Planta Medica, 57(3), pp. 212-216. doi:10.1055/s-2006-960076 Preclinical
    https://doi.org/10.1055/s-2006-960076
  2. Rolland, A., Fleurentin, J., Lanhers, M.C., Misslin, R. and Mortier, F (2001) 'Neurophysiological effects of an extract of Eschscholzia californica Cham. (Papaveraceae)', Phytotherapy Research, 15(5), pp. 377-381. doi:10.1002/ptr.884 Preclinical
    https://doi.org/10.1002/ptr.884
  3. Kalyniukova, A., Ahmed, S., Ak, G., Saka, E. et al (2025) 'Comprehensive Metabolomic Profiling and Biological Activity Analysis of Eschscholzia californica Extracts Using LC-ESI-QTOF-MS', Food Science & Nutrition, 13(9), pp. e70885. doi:10.1002/fsn3.70885 Preclinical
    https://doi.org/10.1002/fsn3.70885
  4. Gafner, S., Dietz, B.M., McPhail, K.L., Scott, I.M., Glinski, J.A., Russell, F.E., McCollom, M.M., Budzinski, J.W., Foster, B.C., Bergeron, C., Rhyu, M.R. and Bolton, J.L (2006) 'Alkaloids from Eschscholzia californica and their capacity to inhibit binding of [3H]8-hydroxy-2-(di-N-propylamino)tetralin to 5-HT1A receptors in vitro', Journal of Natural Products, 69(3), pp. 432-435. doi:10.1021/np058114h Preclinical
    https://doi.org/10.1021/np058114h
  5. Cahlikova, L., Macakova, K., Kunes, J., Kurfurst, M., Opletal, L., Cvacka, J., Chlebek, J. and Blunden, G (2010) 'Acetylcholinesterase and butyrylcholinesterase inhibitory compounds from Eschscholzia californica (Papaveraceae)', Natural Product Communications, 5(7), pp. 1035-1038. doi:10.1177/1934578x1000500710 Preclinical
    https://doi.org/10.1177/1934578x1000500710
  6. Singh, S., Jain, L., Pandey, M.B., Singh, U.P. and Pandey, V.B (2009) 'Antifungal activity of the alkaloids from Eschscholzia californica', Folia Microbiologica, 54(3), pp. 204-206. doi:10.1007/s12223-009-0032-7 Preclinical
    https://doi.org/10.1007/s12223-009-0032-7
  7. Fedurco, M., Gregorova, J., Sebrlova, K., Kantorova, J., Pes, O., Baur, R., Sigel, E. and Taborska, E (2015) 'Modulatory Effects of Eschscholzia californica Alkaloids on Recombinant GABAA Receptors', Biochemistry Research International. doi:10.1155/2015/617620 Preclinical
    https://doi.org/10.1155/2015/617620
  8. Cahlikova, L., Kucera, R., Hostalkova, A., Klimes, J. and Opletal, L (2012) 'Identification of pavinane alkaloids in the genera Argemone and Eschscholzia by GC-MS', Natural Product Communications, 7(10), pp. 1279-1281. doi:10.1177/1934578x1200701008 Preclinical
    https://doi.org/10.1177/1934578x1200701008
  9. Manda, V.K., Ibrahim, M.A., Dale, O.R., Kumarihamy, M., Cutler, S.J., Khan, I.A., Walker, L.A., Muhammad, I. and Khan, S.I (2016) 'Modulation of CYPs, P-gp, and PXR by Eschscholzia californica (California Poppy) and Its Alkaloids', Planta Medica. doi:10.1055/s-0042-103689 Traditional / reference
    https://doi.org/10.1055/s-0042-103689
  10. Hanus, M., Lafon, J. and Mathieu, M (2004) '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', Current Medical Research and Opinion, 20(1), pp. 63--71. doi:10.1185/030079903125002603 Randomized trial
    https://doi.org/10.1185/030079903125002603
  11. European Medicines Agency (HMPC) (2015) 'European Union herbal monograph on Eschscholzia californica Cham., herba'. Available at: https://www.ema.europa.eu/en/documents/herbal-monograph/final-european-union-herbal-monograph-eschscholzia-californica-cham-herba_en.pdf Traditional / reference
    https://www.ema.europa.eu/en/documents/herbal-monograph/final-european-union-herbal-monograph-eschscholzia-californica-cham-herba_en.pdf
  12. Health Canada, Natural and Non-prescription Health Products Directorate (2026) 'Natural Health Product Monograph: California Poppy - Eschscholzia californica'. Available at: https://webprod.hc-sc.gc.ca/nhpid-bdipsn/dbImages/mono_california-poppy_english.pdf Traditional / reference
    https://webprod.hc-sc.gc.ca/nhpid-bdipsn/dbImages/mono_california-poppy_english.pdf
  13. Ghasemzadeh Rahbardar, M. and Hosseinzadeh, H (2024) 'Therapeutic potential of hypnotic herbal medicines: A comprehensive review', Phytotherapy Research, 38(6), pp. 3037-3059. doi:10.1002/ptr.8201 Meta-analysis / review
    https://doi.org/10.1002/ptr.8201
  14. Block, K.I., Gyllenhaal, C. and Mead, M.N (2004) 'Safety and efficacy of herbal sedatives in cancer care', Integrative Cancer Therapies, 3(2), pp. 128-148. doi:10.1177/1534735404265003 Meta-analysis / review
    https://doi.org/10.1177/1534735404265003
  1. Ullah, M.I., Anwar, R., Kamran, S., Gul, B. et al (2022) 'Evaluation of the Anxiolytic and Anti-Epileptogenic Potential of Lactuca serriola Seed Using Pentylenetetrazol-Induced Kindling in Mice and Metabolic Profiling of Its Bioactive Extract', Antioxidants (Basel), 11(11), pp. 2232. doi:10.3390/antiox11112232 Preclinical
    https://doi.org/10.3390/antiox11112232
  2. Lee, M., Park, J., Cho, W., Jun, Y. et al (2024) 'Lactuca L. Extract Enhances Sleep Duration Through Upregulation of Adenosine A1 Receptor and GABA-A Receptor Subunits in Pentobarbital-Injected Mice', Journal of Medicinal Food, 27(7), pp. 661-668. doi:10.1089/jmf.2023.K.0250 Preclinical
    https://doi.org/10.1089/jmf.2023.K.0250
  3. Paulsen, E. and Andersen, K.E (2015) 'Lettuce contact allergy', Contact Dermatitis, 74(2), pp. 67-75. doi:10.1111/cod.12458 Traditional / reference
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  4. Wesolowska, A., Nikiforuk, A., Michalska, K., Kisiel, W. and Chojnacka-Wojcik, E (2006) 'Analgesic and sedative activities of lactucin and some lactucin-like guaianolides in mice', Journal of Ethnopharmacology, 107(2), pp. 254--258. doi:10.1016/j.jep.2006.03.003 Preclinical
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  5. Gumprecht, T (1815) 'On the use of the Lactuca Virosa, in Hooping-Cough', Medico-Chirurgical Transactions, 6, pp. 608-617. doi:10.1177/095952871500600125 Traditional / reference
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  6. Trojanowska, A (2005) 'Lettuce, Lactuca sp., as a medicinal plant in Polish publications of the 19th century', Kwartalnik Historii Nauki i Techniki, 50(3-4), pp. 123-134. Traditional / reference
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  8. Lo Faro, A.F., Di Trana, A., La Maida, N., Tagliabracci, A., Giorgetti, R. and Busardo, F.P (2019) 'Biomedical analysis of New Psychoactive Substances (NPS) of natural origin', Journal of Pharmaceutical and Biomedical Analysis, 179, pp. 112945. doi:10.1016/j.jpba.2019.112945 Meta-analysis / review
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  9. Besharat, S., Besharat, M. and Jabbari, A (2009) 'Wild lettuce (Lactuca virosa) toxicity', BMJ Case Reports, 2009, pp. bcr0620080134. doi:10.1136/bcr.06.2008.0134 Preclinical
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  11. Herbal Reality (n.d.) 'Wild Lettuce (Lactuca virosa): Benefits, Uses, Safety'. Available at: https://www.herbalreality.com/herb/wild-lettuce/ Traditional / reference
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  12. RxList (n.d.) 'Wild Lettuce: Health Benefits, Side Effects, Uses, Dose & Precautions'. Available at: https://www.rxlist.com/supplements/wild_lettuce.htm Traditional / reference
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  13. Ghasemzadeh Rahbardar, M. and Hosseinzadeh, H (2024) 'Therapeutic potential of hypnotic herbal medicines: A comprehensive review', Phytotherapy Research, 38(6), pp. 3037-3059. doi:10.1002/ptr.8201 Meta-analysis / review
    https://doi.org/10.1002/ptr.8201
  14. Block, K.I., Gyllenhaal, C. and Mead, M.N (2004) 'Safety and efficacy of herbal sedatives in cancer care', Integrative Cancer Therapies, 3(2), pp. 128-148. doi:10.1177/1534735404265003 Meta-analysis / review
    https://doi.org/10.1177/1534735404265003

Generated automatically from the Omnia Sana plant database and its cited sources. For educational purposes only — not medical advice. Always consult a qualified practitioner before using medicinal plants.