Botanical name: Avena sativa.  For some herbal supplements, the green or rapidly dried aerial parts of the plant are harvested just before reaching full flower. Many herbal texts refer to using the fruits (seeds) or green tops. Although some herb texts discuss oat straw, there is little medicinal action in this part of the plant. The common oat used in herbal supplements and foods is derived from cultivated sources.

In folk medicine, oats are used by herbalists to treat nervous exhaustion, insomnia, and “weakness of the nerves.” A tea made from oats was thought by herbalists to be useful in rheumatic conditions and to treat water retention. A tincture of the green tops of oats was also used to help with withdrawal from tobacco addiction.  Oats were often used in baths to treat insomnia and anxiety as well as a variety of skin conditions, including burns and eczema.

Oats have been used in connection with high triglycerides, anxiety, eczema, and nicotine withdrawal.

Active constituents: The fruits (seeds) contain alkaloids, such as gramine and avenine, and saponins, such as avenacosides A and B.  The seeds are also rich in iron, manganese, and zinc. The straw is high in silica. Oat alkaloids are believed to account for the relaxing action of oats, but it should be noted this continues to be debated in Europe. The German Commission E does not approve this herb as a sedative.  However, an alcohol-based tincture of the fresh plant has reportedly shown some promise in countering nicotine withdrawal and helping with smoking cessation.

A tea can be made from a heaping tablespoonful (approximately 15 grams) of oats brewed with 1 cup (250 ml) of boiling water. After cooling and straining, the tea can be taken several times a day and shortly before going to bed.5 As a tincture, oats are often taken at 1/2–1 teaspoon (3–5 ml) three times per day. Capsules or tablets, 1–4 grams per day, can be taken. A soothing bath to ease irritated skin can be made by running the bath water through a sock containing several tablespoons of oats, then bathing in the water for several minutes.

Oats are not associated with any adverse effects.  At the time of writing, there were no well-known drug interactions with oats.