Plant Profile

Skullcap

Compiled by the Omnia Sana editorial team from the plant database ·Last updated August 15, 2026

Scutellaria lateriflora

Family: Lamiaceae · Parts used: Aerial parts (flowering herb) · Also known as: American skullcap, Blue skullcap, Mad-dog skullcap

Common names in 8 European languages →

The complete database record: 2 documented constituents, 2 pharmacological actions, 4 traditional / indicated uses, with 18 cited sources.

Botanical Description

Perennial herb (Lamiaceae), 30-80 cm tall, with square stems. Leaves are opposite, ovate to lance-shaped and toothed. Small blue, two-lipped flowers are borne in one-sided leafy racemes arising from the leaf axils; the helmet-shaped calyx gives the genus its 'skullcap' name.^[11]

Height: 30-80 cm

Habit: Erect perennial herb

Leaves: Opposite, ovate to lance-shaped, toothed

Flowers: Small, blue, two-lipped, in one-sided axillary racemes

Stem: Square

Root: Fibrous perennial rootstock

Fruit: Four small nutlets (typical Lamiaceae schizocarp)

Flowering Period: June-September

Habitat & Distribution

Native to North America, growing in damp meadows, marshes, streambanks and wet woodland margins.^[11]

Harvesting

The whole flowering aerial parts are cut at flowering (summer) and dried. Given the well-documented history of adulteration with toxic germander, sourcing from an authenticated, tested supplier is essential rather than home foraging of an uncertain look-alike.^[11]

Parts: Aerial parts (flowering herb)

Season: Summer, at flowering

Key Constituents

Flavonoids (baicalin, baicalein)^{[4, 5, 6, 7, 11, 12]}

Bind the benzodiazepine site of the GABA-A receptor, underlying the calming effect; baicalin is used as the HPLC quality marker, and its content varies widely between commercial tinctures.

Flavonoids

GABA and glutamine (amino acids)^[11]

GABA is the main inhibitory neurotransmitter and contributes to the anxiolytic activity.

Pharmacological Actions

Anxiolytic / calming^{[2, 8, 11, 14]}

Anxiolytic for anxiety and nervous tension (the flavonoids baicalin and baicalein bind the benzodiazepine site of the GABA-A receptor); a randomised, double-blind, placebo-controlled crossover trial in healthy volunteers found significantly improved overall mood without loss of energy or cognition; Calming nervine for stress and nervous disorders (traditional)

Sedative / sleep support^{[1, 11]}

Sedative / sleep support (insomnia)

Traditional & Indicated Uses

Anxiety^{[2, 11, 14]}Moderate · 6/10

Evidence: 6

Label: Anxiety

more plants for anxiety →detailed sources →

Insomnia / sleeplessness^{[1, 11]}Moderate · 5/10

Sedative / sleep support (insomnia)

Evidence: 5

Label: Insomnia / sleeplessness

more plants for insomnia / sleeplessness →detailed sources →

Nervous tension^{[11, 14]}Moderate · 5/10

Evidence: 5

Label: Nervous tension

more plants for nervous tension →detailed sources →

Stress^{[11, 14]}Moderate · 5/10

Calming nervine for stress and nervous disorders (traditional)

Evidence: 5

Label: Stress

more plants for stress →detailed sources →

Traditional Use & History

American skullcap has a Native American and 19th-century Eclectic-medicine tradition as a calming nervine for anxiety and nervous tension - the old name 'mad-dog skullcap' reflects a folk remedy explored for rabies. Modern research on its flavonoids baicalin and baicalein, which bind the benzodiazepine site of the GABA-A receptor, supports its calming, anxiolytic and sleep-supporting reputation.^[11]

Preparations

Infusion (tea)^[11]

Dried aerial parts steeped in hot water - the classic calming preparation.

Tincture^[12]

Alcoholic extract, a common commercial form; content is known to vary widely between products.

Dosage

Infusion (tea) / tincture^{[11, 12]}

Traditional guidance suggests roughly 1-2 g dried herb per cup as an infusion, up to three times daily, or a tincture per product-specific dosing given known variability in flavonoid content between commercial products. Educational reference only, not a prescription; buy only from a source that has authenticated the species and tested for germander adulteration.

Safety, Cautions & Contraindications

Safety note^[11]Info

Generally well tolerated; its sedative effect can add to that of alcohol, sedatives and sleep medicines, and it may inhibit some drug-metabolising (CYP) enzymes.

Safety note^{[11, 12]}Serious

Buy from a reputable source: skullcap products have historically been adulterated with hepatotoxic germander (Teucrium), and the flavonoid content of commercial tinctures varies widely. Safety in pregnancy and breastfeeding is not established.

Herb-Drug Interactions

Sedatives Cns Depressants^{[15, 16]}Caution

Mechanism: Skullcap 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

Dangerous Lookalikes

Teucrium Chamaedrys^{[17, 18]}Dangerous

Confused Part: Dried aerial herb sold or gathered as 'skullcap'; the hepatotoxic herb germander has repeatedly been substituted for or mixed with skullcap in the herb trade.

Confusion Context: American skullcap (Scutellaria lateriflora) is used as a calming herb, but it has repeatedly been adulterated with germander (Teucrium canadense or T. chamaedrys) in the North American herb trade. Germander contains hepatotoxic neo-clerodane diterpenoids and has caused numerous cases of acute hepatitis, some progressing to liver failure; skullcap products contaminated with germander gave 'skullcap' an undeserved reputation for liver toxicity, and a USDA analysis found several commercial 'skullcap' supplements actually contained germander. Because the dried herbs look similar and the substitution persists, this is a real hazard.

Distinguishing Features: Source and testing: the two dried herbs are hard to tell apart by eye, so buy skullcap only from suppliers who authenticate the species - genuine skullcap is rich in flavonoids, whereas germander carries the phenylethanoids verbascoside and teucrioside, and reputable products are laboratory-tested against germander adulteration., Living plant: American skullcap has paired (opposite) leaves and small blue two-lipped flowers borne in one-sided leafy racemes from the leaf axils. Germander (Teucrium) has scalloped, oak-like or narrow leaves and pinkish-purple whorled flower spikes., Caution: because adulteration is common and cannot be judged from a powder, treat any unverified 'skullcap' with caution, especially if you have liver concerns.

Key Test: You usually cannot tell adulterated skullcap from germander by eye, so rely on the source: use only skullcap that a reputable supplier has laboratory-authenticated as Scutellaria lateriflora and tested for germander (Teucrium). On the living plant, skullcap has opposite leaves and small blue flowers in one-sided axillary racemes, unlike germander's whorled pinkish flower spikes. If the source is unverified, do not use it - germander can seriously damage the liver.

Reviewed By: Omnia Sana (owner-authorized)

Reviewed Date: 2026-07-07

Harvest Readiness

^[13]

Part: aerial-parts

Signals: Cut the flowering herb in early summer, while in flower.

Basis: traditional

Source Quote: They are harvested in early summer and dried for later use

Species Confirmed: 1

Notes: PFAF (REF-3339); the flowering aerial parts are cut in early summer (in flower June-August). Single lineage -> provisional. SAFETY: skullcap is adulterated with the hepatotoxic wall germander (Teucrium chamaedrys) - confirm identity/source; see Dangerous Lookalikes.

External Identifiers

GBIF ›Wikidata ›

References & Sources

Di Minno, A., Morone, M.V., Buccato, D.G., De Lellis, L.F. and others (2025) 'Efficacy and Tolerability of a Chemically Characterized Scutellaria lateriflora L. Extract-Based Food Supplement for Sleep Management: A Single-Center, Controlled, Randomized, Crossover, Double-Blind Clinical Trial', Nutrients, 17(9), pp. 1491. doi:10.3390/nu17091491 Randomized trial
https://doi.org/10.3390/nu17091491
Wolfson, P. and Hoffmann, D.L (2003) 'An investigation into the efficacy of Scutellaria lateriflora in healthy volunteers', Alternative Therapies in Health and Medicine, 9(2), pp. 74-78. Randomized trial
https://scholar.google.com/scholar?q=An%20investigation%20into%20the%20efficacy%20of%20Scutellaria%20lateriflora%20in%20healthy%20volunteers
Di Minno, A., Ullah, H., De Lellis, L.F., Buccato, D.G. and others (2024) 'Efficacy and Tolerability of a Cistus x incanus L. and Scutellaria lateriflora L.-Based Chewing Gum on the Symptoms of Gingivitis: A Monocentric, Randomized, Double-Blind, Placebo-Controlled Clinical Trial', Nutrients, 16(6), pp. 862. doi:10.3390/nu16060862 Randomized trial
https://doi.org/10.3390/nu16060862
Wilczanska, A., Sparzak-Stefanowska, B., Kokotkiewicz, A., Jesionek, A. and others (2023) 'Biotechnological strategies for controlled accumulation of flavones in hairy root culture of Scutellaria lateriflora L', Scientific Reports, 13(1), pp. 20422. doi:10.1038/s41598-023-47757-7 Preclinical
https://doi.org/10.1038/s41598-023-47757-7
Cole, I.B., Cao, J., Alan, A.R., Saxena, P.K. and Murch, S.J (2008) 'Comparisons of Scutellaria baicalensis, Scutellaria lateriflora and Scutellaria racemosa: genome size, antioxidant potential and phytochemistry', Planta Medica, 74(4), pp. 474-481. doi:10.1055/s-2008-1034358 Preclinical
https://doi.org/10.1055/s-2008-1034358
Li, J., Ding, Y., Li, X.C., Ferreira, D. and others (2009) 'Scuteflorins A and B, dihydropyranocoumarins from Scutellaria lateriflora', Journal of Natural Products, 72(6), pp. 983-987. doi:10.1021/np900068t Preclinical
https://doi.org/10.1021/np900068t
Tuan, P.A., Kim, Y.S., Kim, Y., Thwe, A.A. and others (2016) 'Molecular characterization of flavonoid biosynthetic genes and accumulation of baicalin, baicalein, and wogonin in plant and hairy root of Scutellaria lateriflora', Saudi Journal of Biological Sciences, 25(8), pp. 1639-1647. doi:10.1016/j.sjbs.2016.08.011 Preclinical
https://doi.org/10.1016/j.sjbs.2016.08.011
Gafner, S., Bergeron, C., Batcha, L.L., Reich, J. and others (2003) 'Inhibition of [3H]-LSD binding to 5-HT7 receptors by flavonoids from Scutellaria lateriflora', Journal of Natural Products, 66(4), pp. 535-537. doi:10.1021/np0205102 Preclinical
https://doi.org/10.1021/np0205102
Gafner, S., Bergeron, C., Batcha, L.L., Angerhofer, C.K. and others (2003) 'Analysis of Scutellaria lateriflora and its adulterants Teucrium canadense and Teucrium chamaedrys by LC-UV/MS, TLC, and digital photomicroscopy', Journal of AOAC International, 86(3), pp. 453-460. doi:10.1093/jaoac/86.3.453 Preclinical
https://doi.org/10.1093/jaoac/86.3.453
Sun, J. and Chen, P (2011) 'A flow-injection mass spectrometry fingerprinting method for authentication and quality assessment of Scutellaria lateriflora-based dietary supplements', Analytical and Bioanalytical Chemistry, 401(5), pp. 1577-1584. doi:10.1007/s00216-011-5246-2 Preclinical
https://doi.org/10.1007/s00216-011-5246-2
Awad, R., Arnason, J.T., Trudeau, V., Bergeron, C., Budzinski, J.W., Foster, B.C. and Merali, Z (2003) 'Phytochemical and biological analysis of skullcap (Scutellaria lateriflora L.): a medicinal plant with anxiolytic properties', Phytomedicine. doi:10.1078/0944-7113-00374 Traditional / reference
https://doi.org/10.1078/0944-7113-00374
Gao, J. and Sanchez-Medina, A. and Pendry, B.A. and Hughes, M.J. and Webb, G.P. and Corcoran, O (2008) 'Validation of a HPLC method for flavonoid biomarkers in skullcap (Scutellaria) and its use to illustrate wide variability in the quality of commercial tinctures', Journal of Pharmacy & Pharmaceutical Sciences, 11(1), pp. 77--87. doi:10.18433/j39g6v Preclinical
https://doi.org/10.18433/j39g6v
Plants For A Future 'Scutellaria lateriflora (Virginian Skullcap)'. Available at: https://pfaf.org/user/Plant.aspx?LatinName=Scutellaria+lateriflora Traditional / reference
https://pfaf.org/user/Plant.aspx?LatinName=Scutellaria+lateriflora
Brock, C. and Whitehouse, J. and Tewfik, I. and Towell, T (2014) 'American Skullcap (Scutellaria lateriflora): a randomised, double-blind placebo-controlled crossover study of its effects on mood in healthy volunteers', Phytotherapy Research, 28(5), pp. 692--698. doi:10.1002/ptr.5044 Randomized trial
https://doi.org/10.1002/ptr.5044
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
Lin, L.Z. and Harnly, J.M. and Upton, R (2009) 'Comparison of the phenolic component profiles of skullcap (Scutellaria lateriflora) and germander (Teucrium canadense and T. chamaedrys), a potentially hepatotoxic adulterant', Phytochemical Analysis, 20(4), pp. 298-306. doi:10.1002/pca.1127 Preclinical
https://doi.org/10.1002/pca.1127
Pacifico, S. and D'Abrosca, B. and Scognamiglio, M. and D'Angelo, G. and Gallicchio, M. and Galasso, S. and Monaco, P. and Fiorentino, A (2012) 'NMR-based metabolic profiling and in vitro antioxidant and hepatotoxic assessment of partially purified fractions from Golden germander (Teucrium polium L.) methanolic extract', Food Chemistry, 135(3), pp. 1957-67. doi:10.1016/j.foodchem.2012.06.071 Preclinical
https://doi.org/10.1016/j.foodchem.2012.06.071

Selected studies & references

ReviewTherapeutic potential of hypnotic herbal medicines: A comprehensive review source↗ (2024)

ReviewSafety and efficacy of herbal sedatives in cancer care source↗ (2004)

RctEfficacy and Tolerability of a Chemically Characterized Scutellaria lateriflora L. Extract-Based Food Supplement for Sleep Management: A Single-Center, Controlled, Randomized, Crossover, Double-Blind Clinical Trial source↗ (2025)

RctEfficacy and Tolerability of a Cistus x incanus L. and Scutellaria lateriflora L.-Based Chewing Gum on the Symptoms of Gingivitis: A Monocentric, Randomized, Double-Blind, Placebo-Controlled Clinical Trial source↗ (2024)

RctAmerican Skullcap (Scutellaria lateriflora): a randomised, double-blind placebo-controlled crossover study of its effects on mood in healthy volunteers source↗ (2014)

RctAn investigation into the efficacy of Scutellaria lateriflora in healthy volunteers source↗ (2003)

PreclinicalBiotechnological strategies for controlled accumulation of flavones in hairy root culture of Scutellaria lateriflora L. source↗ (2023)

PreclinicalMolecular characterization of flavonoid biosynthetic genes and accumulation of baicalin, baicalein, and wogonin in plant and hairy root of Scutellaria lateriflora source↗ (2016)

All 15 studies in the Knowledge Finder →

Educational use only. This profile summarises traditional and scientific sources for reference. It is not medical advice and not a substitute for a qualified practitioner. Some plants carry safety cautions and drug interactions - always check before use.
This profile is assembled automatically from the Omnia Sana plant database, which we curate by hand. How this site is built.

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