L theanine best brands

L-Theanine Supplements Review & Top Pick

ConsumerLab.com uses JavaScript to provide the best possible experience for our content, but your browser has it disabled. Learn how to enable it here.

Save to favorites

This feature is restricted to active members.

Join now to save favorites and get all member benefits, including over 1,300 reviews.

Join Now

Already a member? Sign in here.

Touted for Stress Relief, Do L-Theanine Supplements Work?

As a ConsumerLab.com member, you may print a copy of this report for your personal use.

You can access a special print version by clicking the "Print" icon in the upper right corner of this report. You can then use your web browser's print functions to print the whole report or just selected pages.

You may also email or post a link to this report using the web address above. Non-members using the link will see a free summary and can join to view the full report. Other means of copying or distributing this report, in part or full, are not permitted.

If you are sight-impaired and your computer is having trouble converting the text in this report to speech, contact us for assistance at [email protected] or by phone at 914-722-9149.

Join our Free Newsletter and

Become a Member to View the full L-Theanine Supplements Review!

Become a Member to View the Latest Update: in our L-Theanine Supplements Review

First Name

Email Address

I want to subscribe to ConsumerLab news emails, and I understand that I will have the option in the next step to become a paying member to read the full Review.

* We do not sell or share your personal information with anyone else, ever.

Already a member? Sign in here.

The "Last Updated" date indicates when new clinical information or new product information was most recently added. In the full review, the newest information is highlighted in yellow and, if a new product is added, it is footnoted in the results table, showing the date added to the review.

8 Best L-Theanine Supplements (2023) Reviewed and Compared

Do you feel a rush of relaxation when sipping tea after a stressful day?

Sure, the warming sensation of tea can make you feel “Zen.” But these benefits may also be due to L-theanine, an amino acid associated with relaxation and focus.

Oh look, a neat little table of contents.

What is L-Theanine?

L-theanine – also known as theanine – is an amino acid found most abundantly in green and black tea leaves. However, it differs from the amino acids you may know – like the ones in your post-workout drink.

Theanine is a non-proteinogenic amino acid. It’s not used in protein synthesis.

Instead, it interacts with your brain and nervous system. L-theanine supplements may even slow your brain waves down – something that happens during meditation and before you fall asleep. Talk about relaxation in a bottle!

Health Benefits of Supplementing with L-Theanine

L-theanine may be a natural solution to chronic stress and anxiety.

A 2020 systematic review found 200-400 mg of L-theanine daily improved acute stress and anxiety symptoms.

Its anti-stress properties may be due to the following mechanisms:

  1. L-theanine crosses the blood-brain barrier, where it inhibits excitatory brain activity.
  2. L-theanine stimulates an alpha brainwave state associated with calm, non-drowsy alertness. It’s the feeling of really being in the present moment. Research suggests this may occur just 40 minutes after taking 50–200 mg L-theanine.

If stress and anxiety control your life, theanine is worth a try. Plus, getting into a more relaxed state can have downstream effects on many areas of mental and physical health. I mean, I know I feel a lot better when I’m not stressed.

Supports Mental Focus

Research shows L-theanine improves concentration and reaction times in people with anxiety. It may also improve attention and executive functioning in older people.

However, you can supercharge these effects by combining L-theanine with caffeine. The two have a synergistic relationship. Theanine may even counteract the jittery downsides of caffeine.

This 2010 study found that 97 mg of L-theanine with 40 mg of caffeine reduced tiredness and improved focus and alertness during mentally demanding tasks. Another study found combining them supported alertness, attention span, reaction times, and working memory.

(Skip to the end for more on the health benefits of L-theanine).

8 Best L-Theanine Supplements

With that said, here’s our list of the 8 best L-theanine supplements on the market in 2022. They are all made according to Current Good Manufacturing Practices (cGMP) for quality and safety.

It was tricky organizing this list, simply because all the supplements are great. When you factor in quality, cost, and convenience,  often the simple supplements win out. To get the benefits of l-theanine, we don’t need a supplement for 47 ingredients “proven” for their “nootropic” effects. So our advice is to keep it simple.

*Note: We have affiliate links throughout this article, which means we receive a commission if you purchase from any of our links. This supports our mission to bring complicated health and fitness info in an entertaining package. And it keeps us from putting up annoying things like banner ads. Those suck.

Every product on our list is third-party tested.

1) Double Wood Supplements L-Theanine Capsules

Check Lowest Price

Double Wood L-Theanine comes in convenient 200 mg capsules. Plus, it’s a steal at just $18.95 for 120 capsules. It’s not vegetarian-friendly, but there are other vegetarian options on this list.

Double Wood also goes the extra mile for quality. All of their products are proudly made in the USA, and share their lab results right on the website. Their l-theanine is gluten-free and non-GMO.

They also offer a 100% money-back guarantee. You have nothing to lose.

You can also get $15 off purchases of $100 or more at Double Wood with the code, HEALTH 15 and by using this link.

For the simplicity, quality, and great price, Double Wood L-Theanine is our top choice.

2) Micro Ingredients L-Theanine Powder

Check Lowest Price

Each serving of Micro Ingredients L-Theanine Powder provides 250 mg of pure, plant-based L-theanine sourced from tea leaves. It’s free from fillers and additives and easy on your stomach.

Their powder has a subtle, savory flavor and blends well with water, juice, smoothies, tea, and coffee. I love adding a small amount to my coffee to boost the cognitive benefits and minimize the caffeine “crash.” But you can also use it to make capsules if you’re squeamish about tasting your supplements.

A 100-gram bag contains 400 servings for just $17.94. It’ll last over a year if you take one serving per day.

Micro Ingredients has a wide range of simple, pure nutritional powders. They’re cGMP compliant, and all their products are third-party tested for quality.

3) Pure Bulk L-Theanine (Best Bulk Option)

Check Lowest Price

Pure Bulk L-Theanine is derived directly from tea plants. It’s free from additives and fillers and comes in both capsules and powder. The powder offers the best cost per gram.

Pure Bulk is a third-party trusted brand that provides Certificates of Analysis (COA) for all their products.

4) Life Extension Theanine XR™ Stress Relief

Check Lowest Price

Life Extension Theanine XR tablets contain 400 mg of slow-release L-theanine from green tea. The extended-release technology helps to maintain a steady supply of theanine over six hours. You’ll stay calm and focused when you need it most.

Each GMP-certified tablet also provides 50 mg calcium and 40 mg phosphorus. They use vegetarian capsules, so it’s vegetarian, gluten-free, and non-GMO.

5) Sports Research L-Theanine + Caffeine 2-in-1

Check Lowest Price

If you’re looking for sustained focus Sports Research L-Theanine + Caffeine 2-in-1 formula is your go-to.

In green tea, l-theanine occurs naturally alongside caffeine. This “takes the edge” off the effects of caffeine, and can even reduce the jitters.

Each soft gel delivers 200 mg of Alpha Wave® L-theanine and 100 mg of organic PurCaf® caffeine in medium-chain triglyceride oil from coconut. It’s also certified keto-friendly, gluten-free, and non-GMO.

Alpha Wave is a purified form of L-theanine supported by clinical studies to reduce stress hormones and increase alpha brain wave activity.

6) Doctor’s Best L-Theanine with Suntheanine

Check Lowest Price

Doctor’s Best L-Theanine delivers 150 mg of Suntheanine® per capsule. Suntheanine may be the purest form of theanine on the market. It’s also vegan and free from GMOs, gluten, and soy.

You can grab it from the iHerb store — a marketplace for quality nutritional supplements at affordable prices.

7) Pure Bulk L-Theanine + Melatonin (Best Option for Sleep)

Check Lowest Price

Pure Bulk L-Theanine and Melatonin is a natural sleep aid. Each serving contains 200 mg of the same Pure Bulk L-theanine, paired with 100 mg of melatonin.

Melatonin is the “sleep hormone” secreted by your brain in response to darkness. Combining theanine and melatonin may counteract jet lag and other circadian rhythm disturbances.

For best results, take it an hour before bedtime. However, do NOT take this supplement daily. Taking too much exogenous melatonin can reduce your body’s natural production. 

8) NOW Foods Double Strength L-Theanine

Check Lowest Price

NOW Foods is a cGMP quality-assured brand. Their L-Theanine capsules deliver 200 mg of pure L-theanine plus 100 mg of inositol for extra nervous system support. They are non-GMO, vegan-friendly, and kosher. You can choose between 60 or 120 capsules.

How We Ranked

L-theanine is a simple, well-absorbed supplement. You don’t need to worry about bioavailability, but dose and form are important when buying the best L-theanine supplement for your needs.

Here’s what we took into consideration when ranking the products.

Strict Testing Standards

The FDA doesn’t regulate the supplement industry, and dodgy companies take advantage of this to make a quick buck.

We only choose reputable companies that subject their products to strict third-party testing. All the products are made according to Good Manufacturing Practice (GMP) regulations. You can rest assured each product here contains exactly what it says it does.


These products contain pure l-theanine, without additives, GMOs, and useless fillers.

We also included products containing other ingredients for added benefit. This was the case for Pure Bulk L-Theanine & Melatonin, Sports Research L-Theanine & Caffeine, and Life Extension Theanine XR.


We found theanine in tablet, capsule, and powder form. Capsules and tablets are the most convenient, but powders are cheaper and more versatile.


The products here offer between 100-500 mg of theanine per serving — enough to be therapeutic and safe.


Living a healthy lifestyle shouldn’t be financially stressful. We aim to list quality supplements that are also affordable.


Can L-Theanine Improve Sleep Quality?

The calming effects of L-theanine may encourage sleep quality for those experiencing stress-related sleep disturbances.

This study of people with anxiety found taking between 450–900 mg of L-theanine daily for two months improved sleep satisfaction.

It may also be helpful for children struggling with poor sleep because of ADHD.

What Should I Stack L-Theanine With for Sleep?

If you’re taking l-theanine to help you sleep, consider making yourself an evening supplement stack. Other effective, popular supplements include GABA and magnesium. On its own, l-theanine won’t promote drowsiness, so if sleep is your goal make it a part of your stack.

Double Wood Supplements sells all of these, and if you bundle them you can save. Use code HEALTH 15 to get $15 off your purchase of $100 or more.

While you could buy these together, it’s usually less expensive to grab the individual ingredients and create your own stack.

What Should I Stack L-Theanine With for Cognitive Function?

On the other hand, if you’re taking l-theanine to give a smooth focus for your productivity sessions, pair l-theanine with popular nootropic ingredients. This can include caffeine, l-tyrosine, alpha-GPC, and more. 

Does L-Theanine Lower Blood Pressure?

L-theanine may prevent blood pressure increases during mentally stressful tasks.

As for whether it can lower already high blood pressure, we don’t have data on this yet.

Can L-Theanine Improve Immunity?

This 2019 study found theanine may enhance immunity in athletes by reducing the immune suppressive effects of intense exercise. But we’re not sure if it improves immunity in other situations.

Can L-Theanine Improve Mood?

This study on people with major depressive disorder found that 250 mg of L-theanine per day – taken with their medication – reduced depression and anxiety.

While we’re not 100% sure of the mechanism, animal studies have shown L-theanine boosts “feel-good” neurotransmitters like serotonin and dopamine.

It’s obvious we need more clinical research, but the low-risk nature of L-theanine suggests it may be worth a try. That said, talk to your doctor to confirm if it’s safe for you.

What’s the Best L-Theanine Dose?

Human studies have used 50-900 mg of L-theanine, with no ill effects. However, doses around 200-400 mg may be most effective for anxiety, stress, mental focus, and sleep.

When taken with caffeine, the recommended ratio is 2:1 (for example, 200 mg of L-theanine to 100 mg of caffeine).

When is the Best Time to Take L-Theanine?

  • To boost cognition, take it first thing in the morning, and pair it with your morning coffee for added benefit.
  • Take it 30-60 minutes before bed to improve sleep quality.
  • Taking it in the morning and evening may be helpful for stress and anxiety. However, people with severe anxiety may need 3-4 200 mg doses taken throughout the day.

Does L-Theanine Have Side Effects?

Studies show L-theanine is generally safe for most people. However, it might not help people with already low blood pressure.

We encourage you to talk to your doctor before taking L-theanine, especially if you’re on blood pressure medication. We don’t want you fainting on us.

For another cognition-enhancing supplement, check out our guide on the best choline supplements, which includes info the super popular Alpha-GPC. 

Disclaimer: We are strangers on the internet. Talk to your healthcare provider before taking any dietary supplement, including l-theanine.

iHerb Theanine - Top 5 l-theanine iHerb

  1. Home
  2. Articles
  3. iHerb
  4. Review
  5. L-theanine iHerb

The naturally occurring amino acid L-theanine is renowned for its ability to improve focus and improve brain performance. The main source of amino acids are green (unfermented) tea leaves, which also contain many vitamins and minerals. Today, many dietary supplement manufacturers produce dietary supplements with L-theanine, obtained from natural green tea grown in a natural environment.

The famous iHerb online store offers iHerb quality l theanine in the form of vegetable capsules. Our rating includes iherb L theanine nutritional supplements from trusted manufacturers who have managed to gain the trust of many eicherbomans. With iHerb coupon you can save on purchases.

L-theanine at Eicherb: useful properties

Despite the compatibility of L-theanine and caffeine, which allows you to activate the brain, these amino acids are contained in dietary supplements without additives. Caffeine-free L-theanine normalizes the functioning of the nervous system, which is important for concentration. Natural supplements l theanine iherb have the following effects on the body:

1. instantly starts thought processes;
2. improves night sleep and eliminates daytime sleepiness;
3. prevents drops in blood pressure;
4. Helps fight stress and reduces anxiety.

In addition, the benefits of L-theanine for the elderly have been proven - the dietary supplement maintains clarity of mind and prevents the development of Alzheimer's disease. Natural L theanine iHerb helps to restore speech, which is extremely important for people who have had a stroke. The dosage is set individually, so before you start taking it, it is better to consult a doctor.

iHerb Theanine Products - Top 5 Products

• Natural Factors, Suntheanine, L-Theanine, 100 mg, 60 tabs.
• Now Foods, Theanine, 100 mg, Stress Management, 90 caps.
• California Gold Nutrition, AlphaWave, L-Theanine, 200 mg.
• Jarrow Formulas, Theanine, 200 mg, Dietary Supplement.
• Doctor's Best, L-Theanine Suntheanine, 150 mg, 90 caps.

Which L-theanine to choose at iHerb?

iHerb US marketplace showcases a great selection of iherb l theanine supplements from popular brands. We decided to draw your attention to several especially high-quality theanine products that millions of eicherbomans choose today. The rating will help you choose a good iHerb theanine, reviews of which can be found on the store's website.

Natural Factors, Suntheanine, L-Theanine, 100 mg, 60 tabs. Natural Factors food supplement has a calming and relaxing effect. When taken regularly, iherb theanine improves brain function and increases concentration. To achieve the desired effect, it is enough to take 1-2 tablets three times a day.

Now Foods, Theanine, 100 mg, Stress Management, 90 caps. Now Foods Supplement helps manage stress, calms nerves and improves nighttime sleep. The tool also normalizes blood pressure, so it is recommended for people with hypertension. For daily maintenance of health, 2 capsules are enough - preferably with meals.

California Gold Nutrition, AlphaWave, L-Theanine, 200 mg. The drug brand California Gold Nutrition helps to relax, restore vitality. The amino acid l-theanine iHerb enhances the brain's alpha rhythms, providing natural relaxation without drowsiness. The recommended dose is 1 capsule daily, with or without food.

Jarrow Formulas, Theanine, 200 mg, Dietary Supplement. Jarrow Formulas Amino Acid has a relaxing effect and supports learning. Regular use of the supplement promotes the production of dopamine, which is responsible for the feeling of pleasure. Adults only need to take 1 capsule daily.

Doctor's Best, L-Theanine Suntheanine, 150 mg, 90 caps. Doctor's Best Bio Supplement helps to relax and relieve everyday nervous tension. Also suitable for women suffering from premenstrual syndrome (PMS) symptoms as l theanine iherb improves mood. It is recommended to take 1 capsule daily.

The rating represents a good selection of iherb theanine products, the quality of which is confirmed by the corresponding certificates. Reviews in which buyers share their impressions of taking a particular dietary supplement will help to verify the effectiveness of the drug. For a more detailed description and reviews, you can go to the official website of the store.

More articles

Opti men vitamins iHerb

Optimum Nutrition Opti-Men is a unique vitamin and mineral complex designed specifically for men. Bioadditive will be a great addition to sports nutrition, especially during the drying period of the body, when the body needs vitamin support. The American online store Iherb offers opti men to buy iherb at a good price. ...


Krill oil iHerb

It is impossible to replenish the daily intake of active substances in the body with the help of natural natural sources. To replenish substances such as phospholipids, omega and phosphatidylcholines, doctors recommend eating supplements and dietary supplements, namely krill oil. The best selection of supplements can be found on the iHerb website. ...


Calcium magnesium zinc Eicherb

Vitamin complexes usually contain complementary components necessary to achieve a certain effect. These include vitamins with calcium, magnesium, and zinc, which support healthy bones and muscles. The famous iHerb online store demonstrates an excellent selection of iHerb Calcium Magnesium Zinc D3 products from the best American brands. ...


Eicherb for mastopathy

Mastopathy is a fibrocystic disease characterized by a benign lesion of the mammary glands. Already in the early stages, this disease can cause many problems. When treating mastopathy, you should pay attention to preparations for individual groups of vitamins. You will find high-quality and natural vitamins for the treatment of mastopathy on the iHerb website. ...


Eicherb for prostatitis

Closer to the age of 40, many men experience prostate diseases that bring not only physical, but also moral discomfort. Dietary supplements that can be purchased at the famous Iherb store will help alleviate the symptoms of prostatitis. The range of the iHerb site includes high-quality iHerb products for prostatitis. ...


Mannose Eicherb

Regular outbreaks of cystitis can lead to inflammation of the kidneys, which can result in kidney failure. Treatment for cystitis involves taking mannose, a unique form of glucose that fights directly against the causative agent of inflammation. The iHerb store website offers a huge selection of healthy supplements, among which you will find iHerb d-Mannose at a good price. ...


L-theanine - a quick guide - Blog

The information in this blog has not been verified by your country's public health authority and is not intended for diagnosis, treatment or medical advice. Read more

Daily stress has become a normal part of modern life. Pressure at work, family conflicts, financial pressure, the number of cars on the road and time management are just some of the "stressors" we face on a daily basis. For some people, stress can be overwhelming, leading to feelings of anxiety and insomnia. Fortunately, there are safe and effective natural approaches that provide immediate results when we feel exhausted. One of the top recommendations is L-theanine.

L-theanine, a unique amino acid found almost exclusively in plants of the tea family ( Camellia sinensis ), is one of nature's best compounds for relieving stress and anxiety. L-theanine is the main amino acid in green tea, accounting for 1-2% of the dry weight of tea leaves. The highly purified forms of L-theanine used in dietary supplements are produced through a fermentation process that mimics the natural process found in green tea leaves.

L-theanine: a gentle, natural stress reliever

The effects achieved with L-theanine are amazing. Clinical studies have shown that L-theanine reduces stress, improves sleep quality, reduces PMS symptoms, improves visual acuity, and reduces the negative side effects of caffeine. These clinical effects are directly related to L-theanine's ability to stimulate alpha brain wave activity. The drug helps people to stay calm, focused, focused and brain energy. It also reduces the activity of beta waves associated with nervousness, scattered thoughts and hyperactivity.

In Japan, L-theanine has been approved for use for decades as an aid in coping with stress and promoting relaxation. It is a very popular ingredient in Japanese functional foods and drinks, as well as dietary supplements designed to provide mental and physical relaxation without the effect of drowsiness. L-theanine is a fast acting remedy. Typically, effects are felt within the first 30 minutes and have been shown to last up to 8-12 hours.

At standard doses, eg 100-200 mg, L-theanine does not act as a sedative, but does significantly improve sleep quality. In one double-blind study, L-theanine 200 mg was shown to result in statistically significant improvements in sleep efficiency, a measure of actual sleep time between the time you fall asleep and nocturnal awakenings.

L-theanine - a special brain booster for children

Just like adults, children are exposed to stress and pressure every day. Temporary, minor stress does no harm, and most children do well with it. On the contrary, long-term daily minor stresses accumulate and become just as devastating as major stressful events, wreaking havoc on physical, emotional and mental health. A general sense of insecurity can cause children to experience increased levels of anxiety and depression.

L-theanine stimulates the production of alpha brain waves and also suppresses beta waves (associated with nervousness, scattered thoughts and hyperactivity). This is especially helpful in helping children who have trouble falling asleep and staying asleep because their head refuses to turn off at night. A recent study from the University of British Columbia found that 200mg of L-theanine twice daily was safe and effective in improving some aspects of sleep quality in boys aged 8-12 diagnosed with Attention Deficit Disorder (ADHD).

Learn more