Skullcap: Benefits, Side Effects, and Dosage

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Skullcap (sometimes spelled scullcap) is the common name for Scutellaria, a genus of flowering plants in the mint family.

The name is derived from the Latin word scutella, which means “little dish,” as the small flowers of these plants have a dish- or helmet-like shape. Skullcap is not to be confused with death caps, which are a highly poisonous mushroom (1).

Various parts of skullcaps, such as their roots and leaves, have been used in traditional Chinese and Native American medicine to treat a variety of ailments, ranging from diarrhea to chronic pain.

Today, this plant is widely available in supplement form and purported to provide an array of health benefits, from boosting heart health to relieving anxiety.

This article tells you everything you need to know about skullcap, including its uses, potential health benefits, and side effects.

The name skullcap refers to any plant in the Scutellaria family, though American and Chinese varieties are most commonly used in natural medicine.

American skullcap (Scutellaria lateriflora) is a perennial herb native to North America. In bloom, the plant is covered in tiny, tubular blue flowers, although color can vary (2).

The leaves of American skullcap have been used in traditional herbal medicine as a sedative and to treat conditions like anxiety and convulsions. The plant was prized by Native Americans for its powerful medicinal properties (3).

Chinese skullcap (Scutellaria baicalensis) is native to several Asian countries, as well as Russia.

The dried roots of this plant have been used for centuries as a traditional Chinese medicine known as Huang Qin to treat diarrhea, insomnia, dysentery, high blood pressure, hemorrhaging, respiratory infections, and inflammation (1).

In Asia, Huang Qin is used in herbal remedies, such as Xiao Chai Hu Tang or Sho-saiko-to (SST), a popular formulation used to treat conditions like fevers, gastrointestinal issues, and liver disease (1).

Both American and Chinese skullcap are available as supplements that can be purchased online or in health food stores. Other varieties, such as Scutellaria barbata, are also used in alternative medicine and have been studied for their potential health benefits.

Skullcap is sold in capsules, powders, and liquid extracts. Dried parts of the plant, such as its leaves, are likewise used to brew tea.

Summary

American and Chinese skullcap are flowering plants commonly used in natural medicine to treat a variety of conditions, including insomnia, inflammation, and diarrhea.

Supplementing with skullcap may provide several benefits, though research in most of these areas is limited.

May boost mood and reduce anxiety

American skullcap has been shown to boost mood and reduce symptoms of anxiety.

A study in 43 people found that those who received 1,050 mg of American skullcap daily for 2 weeks reported significant enhancements in mood compared to a placebo group (4).

It’s thought that American skullcap positively impacts mood and reduces anxiety by stimulating gamma-aminobutyric acid (GABA), a neurotransmitter that helps calm nerves (5).

Notably, this plant was used in traditional medicine practices as a sedative and treatment for conditions like insomnia and anxiety.

In fact, many anti-anxiety medications work similarly by enhancing GABA activity (6).

Has antibacterial and antiviral effects

Scutellaria (S.) barbata — also known as barbat skullcap — is another species with medicinal properties. Studies indicate that it has powerful antiviral and antibacterial effects.

One test-tube study sampled over 30 Chinese herbs and found that only S. barbata extract demonstrated 100% antibacterial activity against Acinetobacter baumannii (XDRAB), a bacterium that is a leading cause of pneumonia in hospitalized patients (7).

Furthermore, this extract showed better antibacterial effects than colistin, a common antibiotic.

The same study demonstrated that S. barbata was also effective in reducing XDRAB bacterial load in the lungs of mice, compared to a control group(7).

What’s more, Chinese skullcap is purported to have antibacterial effects and is a component of an herbal mixture called Candbactin, a popular natural remedy used to treat intestinal bacterial overgrowth (8).

Contains anti-inflammatory and anticancer compounds

Both American and Chinese skullcap contain an array of beneficial plant compounds, including antioxidants, which have anti-inflammatory effects and protect your cells from damage caused by molecules called free radicals.

Oxidative stress, which results from an imbalance between free radicals and antioxidants, is linked to a number of chronic conditions, such as certain cancers and heart disease (9).

Notably, baicalin, a flavonoid antioxidant in both American and Chinese skullcap, has demonstrated powerful anticancer effects and may help combat oxidative stress.

For example, in test-tube studies, baicalin induced cell death in prostate and cervical cancer cells while significantly inhibiting the growth of ovarian and pancreatic cancer cells (10).

Scutellarein is another American skullcap compound that exhibits potent anticancer potential in test-tube studies (11).

Additionally, animal studies reveal that wogonin, a flavonoid compound in Chinese and American skullcap, is particularly effective in treating inflammatory allergic conditions like allergic rhinitis (12, 13).

It’s worth noting that Chinese and American skullcap contain many other anti-inflammatory compounds. In fact, over 50 flavonoids have been isolated from the Chinese species alone (12, 13, 14).

Other potential benefits

Skullcap has been linked to several other benefits, including:

• Anticonvulsant effects. Orally supplementing with American skullcap has been shown to have anticonvulsant effects in rodents (15, 16).
• Insomnia. Baicalin, a compound found in both American and Chinese skullcap, is used to treat insomnia in traditional medicine practices. However, research is lacking (17).
• Neurodegenerative disease. Some test-tube studies suggest that American skullcap may have neuroprotective properties, potentially safeguarding against diseases like Alzheimer’s and Parkinson’s (18, 19).
• Heart health. In one animal study, baicalin injections significantly reduced damage associated with an induced heart attack (20).

Although these effects are promising, more research is needed to determine whether skullcap is an effective treatment for these conditions.

Summary

Several types of skullcap — including American and Chinese varieties — are associated with many health benefits, ranging from reduced inflammation to improved mood. However, more human studies are needed.

Although supplementing with skullcap may provide health benefits, it may not be appropriate for everyone and may cause serious side effects in certain cases.

For example, American and Chinese skullcap is associated with liver damage and even liver failure in some people. That said, these cases mostly involved supplements containing multiple herbs, not just skullcap (21).

Even so, people with conditions that impact liver function should avoid this plant altogether.

Chinese skullcap has also been associated with lung complications, and other types — including the American variety — may cause side effects like irregular heartbeat, tics, anxiety, drowsiness, and mental confusion in some people (22, 23).

It should be noted that skullcap can interact with many common medications, such as blood thinners, cholesterol-lowering medications, cytochrome P450 substrate drugs, and pain killers (24).

Additionally, no type of skullcap is recommended for children or pregnant or breastfeeding women due to insufficient safety information (24, 25).

Furthermore, some supplements have been shown to contain adulterants. Others may harbor ingredients not listed on the label (21).

As with any supplement, use caution when purchasing skullcap. Rely on trusted companies that are certified by a third party or independent laboratory.

While different forms have been used since ancient times to treat a variety of ailments, human studies on its safety and effectiveness are lacking. Always consult your healthcare practitioner before taking any herbal supplement, including skullcap.

Summary

Skullcap may lead to serious side effects, such as liver damage, and should not be given to children or taken by people on certain medications, as well as pregnant or breastfeeding women.

Doses of skullcap generally range from 1–2 grams per day, usually in divided doses (23).

However, dosage may depend on the type and form of this herb, so it’s best to check individual supplements for more information.

Teas made of skullcap — sometimes blended with other herbs like lemon balm — are also available in health food stores and online, though they may not have the same effects as supplements because tea is typically less concentrated.

Tinctures containing skullcap and other potentially calming herbs, such as valerian root, are available as well. Dosage for tinctures depends on concentration and ingredients.

Summary

People generally take 1–2 grams of skullcap in divided doses throughout the day, though dosage will depend on your particular supplement. Skullcap is also available in teas and tinctures.

Skullcap is a flowering plant long used in traditional medicine.

Supplementing with skullcap may provide several health benefits, such as improved mood, reduced inflammation, and anticancer effects.

However, human research on skullcap is lacking, and this supplement may cause several adverse side effects.

For this reason, it’s best to consult your healthcare practitioner if you’re interested in taking any form of skullcap.