Skullcap (sometimes misspelt Scullcap) is a member of the mint family and a native of North America, where it thrives in moist woodlands. This North American perennial grows in wet places throughout Canada and the northern and eastern U.S. as well as in other parts of the world, such as southeast Asia. The fibrous, yellow rootstock produces a branching stem from 1-3 feet high, with opposite, ovate, serrate leaves that come to a point. Skullcap's two-lipped flowers are pale purple or blue.

It is also known as Blue Pimpernel, Blue Skullcap, Helmet Flower, Hoodwort, Mad Dog, Madweed, Virginia Skullcap.

Native Americans as well as traditional European herbalists used skullcap to induce sleep, relieve nervousness, and moderate the symptoms of epilepsy, rabies, and other diseases related to the nervous system. In other words, skullcap was believed to function as an herbal sedative.

Skullcap is still popular today as a sedative. Unfortunately, there has been virtually no scientific investigation of how well the herb really works.

When taken by itself, the usual dosage is approximately 1 to 2gm, 3 times per day. However, skullcap is more often taken in combination with other sedative herbs such as valerian, passionflower, hops, and melissa, also called lemon balm. When using an herbal combination, follow the label instructions for dosage. Skullcap is usually not taken long term.

A relative of skullcap, Scutellaria baicalensis, is a common Chinese herb. However, the root instead of the above-ground plant is used, and overall effects appear to be far different.