Omnia SanaPlant Comparison
Wild Lettuce vs Kava
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.
At a glance
Wild Lettuce and Kava: they share 4 indicated uses (anxiety, insomnia / sleeplessness, nervous tension, …); 2 pharmacological actions in common.
Evidence face-off — shared uses
| Condition | Wild Lettuce | Kava | Verdict |
|---|---|---|---|
| Anxiety | 1/10 | 10/10 | Stronger for Kava |
| Insomnia / sleeplessness | 2/10 | 8/10 | Stronger for Kava |
| Nervous tension | 1/10 | 8/10 | Stronger for Kava |
| Stress | 1/10 | 8/10 | Stronger for Kava |
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
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.
The historical medicinal preparation, concentrating the active lactones.
Lipophilic lactones concentrated in the root/rhizome; regarded as the main anxiolytic constituents, acting on GABA-A signalling and other CNS targets.
Chalcone-type constituents of the root; implicated by structure-activity analyses as the components most likely responsible for kava-associated liver injury, which is why water-based extracts of peeled noble-cultivar root are preferred.
Pharmacological Actions
Mild analgesic / anodyne for pain (lactucin and lactucopicrin act on the central nervous system) - in mice these compounds produced analgesia comparable to ibuprofen
Calming for nervous tension and restlessness
Standardised kava extracts significantly reduce anxiety versus placebo in controlled trials (Hamilton Anxiety scale).
Traditional & Indicated Uses
Antitussive for an irritable, dry cough (traditional)
Sedative for sleeplessness / insomnia - lactucin and lactucopicrin showed sedative activity in animal models
Calming for nervous tension and restlessness
Mild analgesic / anodyne for pain (lactucin and lactucopicrin act on the central nervous system) - in mice these compounds produced analgesia comparable to ibuprofen
Directly measured as a treatment target in a 156-patient observational trial of kava extract, where nervous tension and restlessness showed the largest improvements.
Safety, Cautions & Contraindications
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.
Rare but serious drug-induced liver injury (hepatitis, cirrhosis, liver failure) has been reported with kava; it is contraindicated in people with liver disease and should not be combined with alcohol or other medicines that can harm the liver. To reduce risk, use only water-based extracts of peeled root/rhizome from a noble cultivar, keep the dose at or below about 250 mg kavalactones per day, and use short-term only. Stop and seek care for signs of liver trouble (dark urine, jaundice, nausea, abdominal pain).
Kavalactones inhibit several cytochrome P450 enzymes (CYP1A2, 2C9, 2C19, 2D6 and 3A4), which metabolise a large share of prescription medicines. Kava may therefore raise blood levels of such drugs; check with a pharmacist or doctor before combining kava with any regular medication.
External Ids
Botanical Description
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]
Robust, shrubby perennial with thick, jointed, cane-like stems and large, heart-shaped, glossy green leaves. The plant rarely if ever flowers or sets viable seed in cultivation and is propagated entirely by stem cuttings; the thick, knotty underground rhizome and root, the medicinal part, contains the characteristic kavalactone-rich resin.
Habitat
Grows on dry waste ground, roadsides, hedgerows and disturbed soil; native to Europe, North Africa and Western Asia and naturalised in North America.
Native to the islands of the South Pacific (Vanuatu, Fiji, Tonga, Samoa and neighbouring islands); cultivated in warm, humid, shaded tropical conditions.
Harvesting
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]
The root and rhizome are dug from plants at least three to five years old, when kavalactone content is highest, then cleaned, peeled and dried or processed fresh into a beverage.
Traditional Uses
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]
Kava root has a centuries-long ceremonial and social tradition across Pacific Island cultures, prepared as a communal beverage for its calming, sociable and relaxing effects; this traditional anxiolytic reputation is now supported by clinical trials of standardised water-based extracts for anxiety.[6]
Preparations
Peeled root pounded or ground and mixed with water, strained and drunk fresh, the traditional Pacific Island ceremonial and social preparation.
Water-based extract standardised to kavalactone content, taken as capsules; the form used in most clinical anxiety trials, and the safer choice given documented hepatotoxicity concerns with some solvent-extracted products.
Dosage
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.
Clinical trials for anxiety commonly use extracts providing up to around 250 mg kavalactones daily, from water-based extracts of peeled root of a noble cultivar, for short-term use only, given the rare but serious hepatotoxicity risk. Educational reference only, not a prescription.
References
Drug Class Interactions
Lookalikes Review
Synonyms
Not documented
Pairings
Not documented
Kava and valerian are both calming, sedating herbs; taken together they may add up to cause excessive drowsiness, so use caution and avoid before driving or combining with other sedatives.[1]
Kava and passionflower are both relaxing, sedating herbs; combined use may deepen drowsiness and sedation, so use caution.[1]
References & Sources
- 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 - 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 - Paulsen, E. and Andersen, K.E (2015) 'Lettuce contact allergy', Contact Dermatitis, 74(2), pp. 67-75. doi:10.1111/cod.12458 Traditional / reference
https://doi.org/10.1111/cod.12458 - 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
https://doi.org/10.1016/j.jep.2006.03.003 - 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
https://doi.org/10.1177/095952871500600125 - 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
https://scholar.google.com/scholar?q=Lettuce%2C%20Lactuca%20sp.%2C%20as%20a%20medicinal%20plant%20in%20Polish%20publications%20of%20the%2019th%20century - Spadari, M., Pommier, P., Canioni, D., Arditti, J., David, J.M. and Valli, M (2003) 'Abuse of Lactuca virosa', Presse Medicale, 32(15), pp. 702-703. Preclinical
https://scholar.google.com/scholar?q=Abuse%20of%20Lactuca%20virosa - 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
https://doi.org/10.1016/j.jpba.2019.112945 - 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
https://doi.org/10.1136/bcr.06.2008.0134 - Stojakowska, A., Malarz, J. and Kisiel, W (1994) 'Sesquiterpene Lactones in Tissue Culture of Lactuca virosa', Planta Medica, 60(1), pp. 93-94. doi:10.1055/s-2006-959419 Preclinical
https://doi.org/10.1055/s-2006-959419 - Herbal Reality (n.d.) 'Wild Lettuce (Lactuca virosa): Benefits, Uses, Safety'. Available at: https://www.herbalreality.com/herb/wild-lettuce/ Traditional / reference
https://www.herbalreality.com/herb/wild-lettuce/ - RxList (n.d.) 'Wild Lettuce: Health Benefits, Side Effects, Uses, Dose & Precautions'. Available at: https://www.rxlist.com/supplements/wild_lettuce.htm Traditional / reference
https://www.rxlist.com/supplements/wild_lettuce.htm - 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 - 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
- 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 - Pittler, M.H. and Ernst, E (2000) 'Efficacy of kava extract for treating anxiety: systematic review and meta-analysis', Journal of Clinical Psychopharmacology, 20(1), pp. 84-89. doi:10.1097/00004714-200002000-00014 Meta-analysis / review
https://doi.org/10.1097/00004714-200002000-00014 - Smith, K. and Leiras, C (2018) 'The effectiveness and safety of Kava Kava for treating anxiety symptoms: A systematic review and analysis of randomized clinical trials', Complementary Therapies in Clinical Practice, 33, pp. 107-117. doi:10.1016/j.ctcp.2018.09.003 Meta-analysis / review
https://doi.org/10.1016/j.ctcp.2018.09.003 - Zhang, W., Yan, Y., Wu, Y., Yang, H., Zhu, P., Yan, F., Zhao, R., Tian, P., Wang, T., Fan, Q. and Su, Z (2022) 'Medicinal herbs for the treatment of anxiety: A systematic review and network meta-analysis', Pharmacological Research, 179, pp. 106204. doi:10.1016/j.phrs.2022.106204 Meta-analysis / review
https://doi.org/10.1016/j.phrs.2022.106204 - Sarris, J (2018) 'Herbal medicines in the treatment of psychiatric disorders: 10-year updated review', Phytotherapy Research, 32(7), pp. 1147-1162. doi:10.1002/ptr.6055 Meta-analysis / review
https://doi.org/10.1002/ptr.6055 - Pittler, M.H. and Ernst, E (2003) 'Kava extract for treating anxiety', Cochrane Database of Systematic Reviews, 2003(1), pp. CD003383. doi:10.1002/14651858.CD003383 Meta-analysis / review
https://doi.org/10.1002/14651858.CD003383 - Teschke, R., Qiu, S.X., Xuan, T.D. and Lebot, V (2011) 'Kava and kava hepatotoxicity: requirements for novel experimental, ethnobotanical and clinical studies based on a review of the evidence', Phytotherapy Research, 25(9), pp. 1263-1274. doi:10.1002/ptr.3464 Meta-analysis / review
https://doi.org/10.1002/ptr.3464 - Wang, Yingli and Su, Chao and Zhang, Bo and Niu, Yang and Ren, Ruru and Zhao, Xiaojun and Yang, Lingling and Zhang, Wannian and Ma, Xueqin (2021) 'Biological Activity, Hepatotoxicity, and Structure-Activity Relationship of Kavalactones and Flavokavins, the Two Main Bioactive Components in Kava (Piper methysticum)', Evidence-Based Complementary and Alternative Medicine, 2021, pp. 6851798. doi:10.1155/2021/6851798 Meta-analysis / review
https://doi.org/10.1155/2021/6851798 - Sarris, J., Kavanagh, D.J., Adams, J., Bone, K. and Byrne, G (2009) 'Kava Anxiety Depression Spectrum Study (KADSS): a mixed methods RCT using an aqueous extract of Piper methysticum', Complementary Therapies in Medicine, 17(3), pp. 176-178. doi:10.1016/j.ctim.2009.01.001 Randomized trial
https://doi.org/10.1016/j.ctim.2009.01.001 - Kuchta, Kenny and Hladikova, Marie and Thomsen, Michael and Nahrstedt, Adolf and Schmidt, Mathias (2020) 'Kava (Piper methysticum) Extract for the Treatment of Nervous Anxiety, Tension and Restlessness', Drug Research, 71(2), pp. 83-93. doi:10.1055/a-1268-7135 Clinical study
https://doi.org/10.1055/a-1268-7135 - Anke, Jennifer and Ramzan, Iqbal (2004) 'Pharmacokinetic and pharmacodynamic drug interactions with Kava (Piper methysticum Forst. f.)', Journal of Ethnopharmacology, 93(2-3), pp. 153-160. doi:10.1016/j.jep.2004.04.009 Meta-analysis / review
https://doi.org/10.1016/j.jep.2004.04.009 - Pittler, M.H. and Ernst, E (2003) 'Kava extract for treating anxiety', Cochrane Database of Systematic Reviews, 2003(1), pp. CD003383. doi:10.1002/14651858.CD003383 Meta-analysis / review
https://doi.org/10.1002/14651858.CD003383
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.