The following article first appeared at Health.com and was written by Robert Barnett.  We have included the section here that discusses the amino acid L-Theanine, but please read the whole story to discover the other 18 natural remedies for anxiety.

You’re anxious, worried, freaked. You’re upset about (pick one): money, health, work, family, love. Your heart is beating fast, your breathing is shallow and rapid, your mind is imagining doom, and you wish you could just relax…now! Whether you have a full-blown anxiety disorder or are just freaking out, you may not want to try medication—at least not yet.

There are many safe nondrug remedies for anxiety, from mind-body techniques to supplements to calming teas. Some start working right away, while others may help lessen anxiety over time.

L-theanine (or green tea)

They say Japanese Buddhist monks could meditate for hours, both alert and relaxed. One reason may have been an amino acid in their green tea called L-theanine, says Mark Blumenthal, of the American Botanical Council.

Research shows that L-theanine helps curb a rising heart rate and blood pressure, and a few small human studies have found that it reduces anxiety. In one study, anxiety-prone subjects were calmer and more focused during a test if they took 200 milligrams of L-theanine beforehand.

You can get that much L-theanine from green tea, but you’ll have to drink many cups—as few as five, as many as 20.