What Does L-Theanine Do?

L-theanine is an amino acid found in green tea and other types. Researchers have become interested in L-theanine in recent years for its potential benefits in helping improve attention span and focus in people with attention-deficit/hyperactivity disorder.

This article provides an overview of L-theanine and ADHD.

L-Theanine Research: Minimal But Intriguing

Research on the effects of L-theanine, particularly in people with ADHD, is in its initial stages. Only a handful of small studies have been completed, with inconclusive results. So, doctors emphasize that people using standard ADHD therapies should not alter their regimens.

In fact, many of the completed studies have been on people already receiving treatment for ADHD. Consequently, even positive results aren’t indicators that L-theanine can or should replace ADHD medications.

Still, the data is intriguing. Studies suggest a link between L-theanine consumption and improvements in concentration, thinking and performance in cognitive tasks. At least one study looked at brain scans of a handful of boys with ADHD and detected changes in brain areas related to distraction. The participants also had higher scores on cognitive tests when consuming L-theanine and caffeine.

These types of results cause researchers and physicians to wonder if L-theanine could complement existing treatments.

Is L-Theanine Safe?

Research has not identified any severe side effects of getting L-theanine from green tea or supplements. People have reported nausea, and some children have developed facial ticks when taking L-theanine, but that side effect resolved when they stopped taking it. So, experts consider it relatively safe.

However, the lack of rigorous testing, studies focused on drug interactions and dosing guidelines mean you should proceed with caution if you decide to try L-theanine. It’s also essential to talk with your doctor before taking L-theanine or other supplements.

How Much L-Theanine Should I Take?

As noted above, there are no official dosing recommendations. However, it’s common for studies to use 2.5 mg per kilogram of body weight per day for children and 200 mg total per day for adults. Adults taking L-theanine regularly often consume up to 400 mg per day.

Supplements provide a more consistent way to consume L-theanine. The amount you get from drinking a cup of green tea will vary based on the tea brand, how long you let it steep and other factors. But you can expect to consume around 25 mg per cup.

Research into L-theanine’s effects includes assessing it when taken with or without caffeine. For example, one study found that L-theanine with caffeine lowered impulsivity in children with ADHD. Another indicated that test groups who received L-theanine alone or L-theanine plus caffeine both showed significant improvement in ADHD symptoms versus placebo.

So, if you’re interested in trying L-theanine, you should ask your doctor if consuming it with or without caffeine would be best for you.

Talk With Your Baptist Health Doctor About L-Theanine and ADHD

L-theanine is an amino acid that shows promise as a complementary treatment for ADHD. Studies continue, and while L-theanine is not a replacement for existing treatments, some research suggests it may play a supportive role.

Talk with your Baptist Health physician to learn more about the potential benefits of L-theanine for ADHD and focus. If you don’t have one, you can find a doctor in our online provider directory.

Next Steps and Helpful Resources

Learn More About Behavioral Care at Baptist Health
Adult ADHD Diagnosis & Treatment
What is the Difference Between ADD and ADHD?
ADHD and Alcohol
How Social Media Affects Attention Span