Oat Straw Tea: What It Is and What Research Says

Posted by Ricardo R. Matos, Founder of Tea The World on May 30th 2025

Oat Straw Tea: What It Is and What Research Says

By Ricardo R. Matos, Founder of Tea The World
Updated October 2026 · Reviewed against published research

What Is Oat Straw Tea?

Oat straw tea is made from the dried green stems and leaves of the oat plant, Avena sativa, usually harvested while the grain is still immature (sometimes called “milky oats”). It has a long history in Western herbal traditions as a gentle, everyday tonic and brews into a mild, grassy, slightly sweet cup that is naturally caffeine-free.

What’s in It?

Oat plants contain minerals such as silica, calcium, and magnesium, along with antioxidant compounds called avenanthramides. Keep in mind that a brewed cup of tea contains only a small fraction of the plant’s nutrients, so oat straw tea is not a meaningful source of vitamins or minerals on its own.

What Research Says

Research on oat straw is limited, and most of it uses concentrated green oat extracts rather than brewed tea. The findings below are research observations, not promises about any one cup.

Attention and mood

A few small clinical studies of a standardized green oat extract have reported short-term effects on attention and concentration in healthy adults. In one 2017 study of middle-aged adults, a single 800 mg dose of concentrated extract led to faster task performance and fewer memory errors. That is far more concentrated than a cup of tea, the studies were small, and the results have not been widely replicated.

Circulation

Some early research has looked at oat extracts and blood flow, but the evidence is preliminary.

Traditional use

Herbalists have traditionally used oat straw as a calming, “restorative” tea. These are traditional uses rather than findings proven in clinical trials.

Overall, oat straw tea can be a pleasant, caffeine-free part of a calm routine, but it is not a treatment for any condition.

Safety Notes

  • Gluten: Oat products can be cross-contaminated with gluten. People with celiac disease should choose products certified gluten-free.
  • Allergies: Avoid it if you are allergic to oats.
  • Medications and pregnancy: Talk with a healthcare provider before using herbal products if you are pregnant, breastfeeding, have a health condition, or take medications.

How to Brew Oat Straw Tea

  1. Use 1 to 2 teaspoons of dried oat straw per 8 oz cup.
  2. Pour freshly boiled water over the herb.
  3. Cover and steep 10 to 15 minutes. Herbalists sometimes make a stronger overnight infusion.
  4. Strain and enjoy plain, or blend with peppermint or chamomile for more flavor.

Looking for caffeine-free favorites? Try Egypt Simply Chamomile or Morocco Simply Tea Peppermint from Tea The World.

This article is for general education and is not medical advice. If you have a health condition, are pregnant, or take medication, talk with your doctor before using herbal teas for health reasons.

Sources

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