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SKULLCAP (Scutellaria lateriflora)

Family: Labiatiae family (mint)
Synonyms: Scullcap, Mad-dog weed, Madweed (1), helmet flower,
Hood-wort (2), Blue Pimpernel, Quaker Bonnet (3), blue skullcap (4)

Downloadable PDF of this information sheet

Plant characteristics

 
Grows up to 3 feet tall, spreads readily. Leaves are toothed ovate to lanceolate, with paired blue flowers just above the leaves on one side of the slender, square branching stem (2,5).The seed pods look like little lipped bells (1) or “caps”. The plant is native to North America, perennial and hardy to Zone 4. It thrives in fertile soil with plenty of water in partial shade or full sun (5). For peak medicinal activity, the entire herb above ground should be harvested when it begins to flower in the summer and then dried in the shade (5).

Herb medicinal and properties

Biologically-active chemicals: volatile oils, tannins, and flavonoids, compounds that reduce binding to a serotonin receptor in the brain which may have an effect on sleeplessness, depression, migraine, pain, and memory loss (6).

The specific biochemistry of this herb is still under investigation. Current studies suggest that it has an effect similar to anti-anxiety drugs such as Valium without the side effects of decreased attention (4).

Herbal properties: nervine tonic, sedative, antispasmodic (7).

How herb was used traditionally

Known to indigenous Americans (2) and early colonial doctors as a treatment for rabies (8). Subsequently used to treat a variety of nervous complaints, including “female weakness” (8), epilepsy and uncontrollable movements (7). Was in The United States Pharmacopeia from 1863-1916 and in The National Formulary until 1947.

Preparation and dosage:
Traditionally administered as a tea (1-2 grams in 1 cup of boiling water three times daily) or an alcohol-based tincture (1/2- 1 teaspoon of a 1:3 strength tincture three times daily) (9).

How herb is used today (based on scientific evidence)

Little scientific evidence to support use despite long and continued use of the herb by herbalists. A small 2003 clinical trial showed that skullcap significantly reduced anxiety in healthy volunteers, with a peak effect at one hour (4).

Has been used to treat stroke, fever, elevated cholesterol, atherosclerosis, epilepsy, hysteria, nervous tension, allergies, dermatitis, inflammation, and spasms (3).

Michael Tierra, L.Ac., O.M.D. successfully treats alcohol and drug withdrawal with skullcap (7).

Safety issues

Some herbalists say that large doses can cause dizziness, confusion and palpitations (9). Doctors have reported incidents of liver toxicity in patients taking a combination of drugs and herbal preparations containing skullcap and other herbs. It is not clear if the liver damage was due to the skullcap, the other drugs and herbs, a contaminant in the herbal preparation, or a combination of factors. Skullcap has not been clearly implicated as a cause of severe side effects (4,8,9). Dr. Low Dog recommends that doctors check liver function blood tests in patients who take large doses of skullcap over long periods so that they will be sure that skullcap has no adverse effects (9).

Skullcap’s safety in pregnancy and breast-feeding is unknown. We do not know if certain people with other illnesses should not take skullcap. We do not know if skullcap interacts with medications, though we suspect it would cause a greater effect of any drug capable of causing drowsiness like Ativan, Valium, and, perhaps, Prozac, as well as antihistamines and alcohol.

References
1. Grieve M: A Modern Herbal. New York, Dover Publications, Inc, 1971.
2. Hutchens AR: Indian Herbology of North America. Boston, Shambhala Publications, Inc., 1991.
3. Jellin JM, Gregory PJ, Batz F, et al: Pharmacist's Letter/ Prescriber's Letter Natural Medicines Comprehensive Database, vol 2004. Stockton, CA, Therapeutic Research Faculty, 2004.
4. Wolfson P, Hoffmann DL: An investigation into the efficacy of Scutellaria lateriflora in healthy volunteers. Altern Ther Health Med 9(2):74-8, 2003.
5. Sturdivant L, Blakeley T: The Bootstrap Guide to Medicinal Herbs in the Garden, Field, & Marketplace. Friday Harbor, WA, San Juan Naturals, 1999.
6. Gafner S, Bergeron C, Batcha LL, et al: Inhibition of [3H]-LSD binding to 5-HT7 receptors by flavonoids from Scutellaria lateriflora. J Nat Prod 66(4):535-7, 2003.
7. Tierra M: The Way of Herbs. New York, Pocket Books, 1998.
8. Foster S, Tyler VE: Tyler's Honest Herbal: A sensible guide to the use of herbs and related remedies. Binghamton, NY, The Haworth Herbal Press, 1999.
9. Low Dog T: Foundations of Herbal Medicine. Albuquerque, 2000.
10. Strategic Reports: Analysis of the economic viability of cultivating selected botanicals in North Carolina. A report commissioned for the North Carolina Consortium on Natural Medicinal Products. Raleigh, NC, North Carolina State University, 2002.

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