L-theanine: A Nutrient in White, Green & Black Tea with Amazing Benefits

Many of us associate drinking a cup of tea with relaxation, and there’s definitely something to this. L-theanine is an incredible amino acid found in many types of tea, notably white and green tea. It’s also found in black tea, some mushrooms, and supplements. Many love this amino acid for its relaxing properties, which may help with anxiety, stress, and insomnia. 

Interested in learning more? Let’s explore L-theanine’s purported health benefits, the science backing these claims, and some of our favorite teas containing L-theanine.

1. May Reduce Anxiety and Insomnia

L-theanine’s most popular health benefit is its ability to encourage lessened anxiety and stress — something that almost everyone can use at one point or another! 

Researchers have found that L-theanine supplements may increase GABA, dopamine, and serotonin levels in the body, which promotes greater relaxation and lessened anxiety. They concluded that the participants experienced fewer stress-related symptoms (like anxiety, sleep issues, or depression) and improved cognitive function. 

Plus, individuals taking L-theanine had reduced issues with sleep quality compared to the placebo group! 

But that’s not all. A 2019 study found that a combination of L-theanine and GABA improved sleep quality and duration compared to taking either alone. Specifically, researchers found that sleep latency, or the delay of sleep, decreased by 14.9%, and sleep duration increased by 26.8%.  

According to The Cleveland Clinic, L-theanine in tea or supplements can be consumed before bed to help with insomnia, but it should be non-caffeinated. The Cleveland Clinic also reports that L-theanine is generally safe and well-tolerated (but always check with your physician first).

2. May Boost Mental Sharpness and Clarity

White, Green tea and some black teas contain L-theanine, and both beverages contain varying levels of caffeine, which we all know can give us a much-needed boost in energy here and there! (For more information about caffeine content of teas, check out our previous article all about it). 

What’s unique about caffeine combined with L-theanine is that many still find the caffeine stimulating, but the L-theanine can help with those caffeine jitters some of us experience. 

One study examined the effects of L-theanine and caffeine on participants and found that it significantly improved accuracy during task switching. Participants even self-reported being more alert and less tired. Overall, the study concludes that this combination may be helpful for anyone taking on a demanding cognitive task, such as writing, doing your taxes, or helping your kids with their math homework.

3. May Encourage Better Immunity

We’ve all heard that white and green tea are good for you, but recent research has revealed even more interesting and specific benefits that white and green tea, specifically L-theanine, has on the immune system. 

One study on patients who had a distal gastrectomy surgery demonstrated that theanine enhanced recovery, possibly by reducing inflammation in the intestinal tract. 

Another found that the antioxidants and L-theanine in green tea may effectively prevent the flu. 

Interestingly, this study was on healthcare workers who are exposed to more contagions than most of us. The theanine group had significantly lower rates of influenza, which is pretty amazing!

4. May Aid Blood Pressure Management

Researchers are studying L-theanine for its purported ability to help with blood pressure management in stressful situations. 

A study published in the National Library of Medicine found that L-theanine intake “significantly inhibited the blood-pressure increases in the high-response group,” especially when compared with the placebo group. Caffeine was also examined in this study, but it was found to have a lesser effect on blood pressure than L-theanine. 

Researchers conclude that L-theanine has many therapeutic health benefits, including possible effects on learning ability, vascular relaxation, cancer suppression, and immune function. According to this study, it even promotes a relaxed state without increasing drowsiness.  

Our Favorite Teas & L-theanine Supplements

Are you interested in trying L-theanine? We love drinking delicious green tea to reap the benefits of this soothing amino acid. 

Here are a few of our favorite green teas: 

• L-Theanine Capsules: These capsules may help ease occasional anxiety, tension, and agitation. Some adults also find them helpful for promoting better sleep quality, healthier blood pressure levels, and enhanced cognitive performance. 
• Matcha Green Tea Powder: Matcha is a popular green tea with a robust, full-bodied flavor. It’s especially rich in antioxidants and is a known nootropic (meaning it may help with mental clarity, alertness, and focus). Plus, it’s popular among many as an aid during weight loss. 
• Mint Gunpowder Green Tea: A must-have for any mint lovers out there! Our Mint Gunpowder Green Tea is intense with sweet, minty notes and a lightly smoky profile. Absolutely delicious, hot or iced! 
• Vanilla Gunpowder Green Tea: If you’re looking for the ultimate, calming tea, this is it. Vanilla is a universally loved flavor believed to calm the nerves and mind and lift the spirits. With delicious green tea and its powerful L-theanine, this is a great choice to encourage peace on a hectic morning. 
• Raspberry Green Tea: If you like a sweet, fresh taste, this Raspberry Green Tea is delightful. It’s composed of rose petals, raspberries, raspberry leaves, and China Green Tea. You’ll love the refreshing taste to encourage and uplift your mind and body. 
• Jasmine Green Tea with Flowers: A staple in so many tea lovers’ pantries! Jasmine Green Tea with Flowers is a sensuous, floral-tasting tea with beautiful jasmine blossoms, making this a treat for your eyes and body. 
• Ginseng & Ginger Green Tea: This energizing green tea combines zesty ginseng with sweet, earthy China green tea and ginger. It’s perfect for putting a spring in your step first thing in the morning! 

If you’re looking for an alternative to tea, try our Green Tea Capsules or Matcha Tea Capsules. Both provide a boost of green tea, a known antioxidant that may help with weight management, energy levels, and the other benefits we’ve discussed in this article. 

We hope you found this overview of L-theanine’s benefits helpful! This lone amino acid has so many notable studies and purported benefits, and we can’t wait to see what future research reveals about it. 

Well Wishes, 

Herbalist Natalie & Herbalist Leilah