American skullcap derives its name from the caplike appearance of the outer whorl of its small blue or purple flowers. It is a slender, heavily-branched plant that grows to a height of 2 to 4 feet and blooms each July. It grows wild in woods and meadows.
Chinese skullcap is related to and resembles American skullcap, but it is a different plant. Its single stems bear a profusion of blue or purple flowers.
Parts UsedAmerican skullcap
The leaves are used for medicinal purposes. These are harvested in June from a 3- to 4-year-old skullcap plant.Chinese skullcap
The root is used medicinally.
American skullcap is available as a powder or liquid extract.
Chinese skullcap is available as a powder.
How to Take ItPediatric
Neither American skullcap nor Chinese skullcap is recommended for children.Adult
Skullcap is available as an encapsulated dried herb, tea, fluid extract, and tincture. Speak to your physician to find the right form and dose for your needs.
Chinese skullcap is often combined with other herbs into a preparation; follow dosing recommendations on the label.
The use of herbs is a time-honored approach to strengthening the body and treating disease. However, herbs can trigger side effects, and can interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care provider.American skullcap
- In the past, American skullcap has been contaminated with germander (Teucrium), a group of plants known to cause liver problems. It is important that American skullcap be obtained from a reliable source.
- High doses of the tincture may cause giddiness, stupor, mental confusion, twitching, irregular heartbeat, and seizures.
- American skullcap should not be used during pregnancy and breastfeeding.
- If you have diabetes, DO NOT take Chinese skullcap without your doctor's supervision. Chinese skullcap may lower blood sugar levels, raising the risk of hypoglycemia (low blood sugar).
- Avoid Chinese skullcap if you have stomach or spleen problems.
- Chinese skullcap should not be used during pregnancy or breastfeeding.
If you are being treated with any of the following medications, you should not use either American skullcap or Chinese skullcap without first talking to your health care provider.Sedatives
Both American skullcap and Chinese skullcap can increase the effect of drugs that have a sedating effect, including:
- Anticonvulsants, such as phenytoin (Dilantin) and valproic acid (Depakote)
- Benzodiazepines, such as alprazolam (Xanax) and diazepam (Valium)
- Drugs to treat insomnia, such as zolpidem (Ambien), zaleplon (Sonata), eszopiclone (Lunesta), and ramelteon (Rozerem)
- Tricyclic antidepressants, such as amitriptyline (Elavil)
The same is true of herbs with a sedating effect, such as valerian, kava, and catnip.Drugs for Diabetes
Chinese skullcap can lower blood sugar, and could strengthen the effects of drugs taken for diabetes, increasing the risk of hypoglycemia (low blood sugar).
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