Best L-Theanine Supplement (Capsules & Powder) — Top Brands of 2023

Are you looking for the best, most potent l-theanine supplement for your health needs and proven nootropic results?

Best L-Theanine Supplement (Capsules & Powder)

L-theanine is a popular ingredient in nootropic supplements and stacks because it compliments many relaxing effects and improves cognitive function.

It is a powerful amino acid found in green tea but offers even better results when it is found in dietary supplements.

Some l-theanine supplement blends are targeted for specific benefits, while others have a broader range of effects.

So how are you supposed to find the best one through all the unique products and blends available? With our review, you don’t have to guess anymore.

Top 6 L-Theanine Supplements On The Market

  1. Mind Lab Pro — Best L-Theanine Supplement Stack Overall
  2. Performance Lab Caffeine+ — Best Caffeine and L-Theanine Supplement For Energy
  3. Thorne Research Theanine — Best Suntheanine Supplement for Relaxation
  4. Jarrow Formulas Theanine — Best L-Theanine Supplement For Anxiety
  5. BulkSupplements L-Theanine Powder — Best L-Theanine Powder
  6. Doctor’s Best L-Theanine — Best L-Theanine Capsules For The Money

Best L-Theanine Supplement Stack Overall

All the best l-theanine supplements combine high-quality, research-based ingredients to offer proven results and beneficial nootropic properties. This blend will provide a full spectrum of health benefits as a balanced nootropic supplement.

Best l-theanine stack

#1 Mind Lab Pro

Mind Lab Pro helps to boost mood and raise energy levels while offering the ability to reduce brain fog and improve overall cognitive performance.

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Mind Lab Pro is a perfect blend of 11 different nootropics, vitamins, and natural ingredients to provide a full spectrum of health benefits.

In addition to 100 mg of L-theanine as the ingredient Suntheanine, it also has effective doses of lion’s mane mushroom, bacopa monnieri and rhodiola rosea.

The composition is designed to boost the brain’s natural process and offer a calming, mood-boosting, and cognition-enhancing nootropic stack.

Mind Lab Pro does not contain any useless fillers, and all other ingredients play a role in the overall effects and benefits. It is a powerful and proven l-theanine stack for purity, value, and results.


  • 11 combined ingredients for well-rounded benefits
  • The amount of every substance is listed on the bottle
  • All-natural, allergen and gluten-free, non-GMO, and no crash
  • Every element meets the highest quality requirements
  • Beneficial for overall cognition, mood, and memory


  • More expensive than other L-theanine supplements

Best Caffeine and L-Theanine Supplement For Energy

Since l-theanine can give a lasting energy boost without nasty side effects like jitters, nervousness, it is often combined with a dose of caffeine for better results. The best energetic l-theanine supplements combine Suntheanine with other ingredients to offer a balanced and smooth experience.

Best Caffeine and L-Theanine

#2 Performance Lab Caffeine+

Performance Lab Caffeine+ is a splendid choice for providing a clean, energetic feeling that can ward off mental fatigue and burnout while increasing motivation and improving productivity.

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Performance Lab Caffeine+ has natural ingredients designed to amplify the energetic benefits of l-theanine. It contains a moderate dose of caffeine derived from Coffea robusta seeds.

The l-theanine (as Suntheanine), l-tyrosine, and combination of B vitamins reduce the potential side effects of the caffeine.

L-tyrosine is an amino acid found naturally in food products, but the dose found in Performance Lab Caffeine+ compliments the l-theanine to help with motivation, focus, and concentration. The impact of these benefits is better performance and work production.


  • Contains 7 ingredients with no fillers
  • A good option for both mental and physical energy
  • Clean stimulation with little to no side effects
  • Label transparency with dosage listed on the bottle


  • Only available on the Performance Lab official website

Best Suntheanine Supplement for Relaxation

Suntheanine is a brand name for l-theanine produced using a patented process that mimics the natural process of green tea leaves, making the purest form of market-produced l-theanine. The best Suntheanine supplements readily cross the blood-brain barrier to highlight the relaxation qualities of the l-theanine by increasing alpha brain waves.

Thorne Research Theanine
Best Suntheanine capsules

#3 Thorne Research Theanine

Thorne Research Theanine is an excellent choice for supporting mental tranquility and promoting a restful, relaxed state that can be used for stress relief or to improve sleep quality.

Thorne Research Theanine is a great product to help you relax throughout the day because it contains only potent and pure Suntheanine.

Relaxation from l-theanine can help with a healthy stress response and ease after a hard, frustrating day at work.

The l-theanine found in the supplement targets GABA production that can promote a relaxed state that can, in turn, lower heart rate and blood pressure.

Some people even use Thorne Research Theanine for improving sleep quality. The wave of relaxation that it promotes can help someone fall asleep fast.

However, it does not cause overwhelming sleepiness if you are not planning for bedtime as a nootropic. It can also be helpful to reduce the side effects of caffeine or other stimulants.


  • Only uses pure ingredients
  • Gluten-free and allergen-free
  • High-quality Suntheanine (l-theanine) substance


  • Only contains l-theanine, unlike some competitors
  • More expensive compared to other l-theanine supplements

Best L-Theanine Supplement For Anxiety

L-theanine is known for promoting a healthy mood and reducing stress and anxiety symptoms. The best l-theanine products for someone with an anxiety disorder will offer a rapid onset with prolonged benefits to ensure less anxiety throughout the day.

Jarrow Formulas Theanine
Best for anxiety

#4 Jarrow Formulas Theanine

The overall best supplement for stress relief and treating anxiety without causing drowsiness, brain fog, and other side effects is Jarrow Formulas Theanine.

The l-theanine found in Jarrow Formulas Theanine influences neurotransmitters, including GABA, dopamine, and serotonin, to boost the body’s stress response.

It also encourages a positive mood, even in stressful situations or with higher stress levels than usual.

People with generalized anxiety disorder often use this supplement to reduce anxiety without the extreme side effects that prescription drugs can cause.

In addition, it can calm the mind and body and make it easier to battle through stress and anxiety without intoxication or brain fog.


  • Targets neurotransmitters and increases alpha brain waves
  • Vegan and vegetarian friendly
  • Reasonable price for quality l-theanine supplementation


  • It works best when you stack it with other supplements for anxiety and stress
  • Doesn’t contain Suntheanine

Best L-Theanine Powder

Many people prefer l-theanine in powder form because it is more affordable. Not only that but using powder opens up more options for taking l-theanine like adding it to coffee or using it sublingually. Still, the best l-theanine powder options offer genuine purity, proven research-based results, and the best value for your money.

BulkSupplements L-Theanine Powder
Best l-theanine powder

#5 BulkSupplements L-Theanine Powder

BulkSupplements L-Theanine Powder is affordable and potent for powerful and lasting results for brain health and focus.

L-theanine supplements are often expensive, especially when you buy capsules. Still, BulkSupplements L-Theanine Powder is affordable and offers proven benefits for a healthy mood, improved focus, and alertness.

It also enhances cognitive performance with only a tiny amount of powder. This product also packs easily into capsules, or you can mix it into your morning coffee.

Some people like to mix it with juice for steady consumption throughout the day for a consistent and flowing benefit to cognition and mental clarity.


  • Powerful and only requires a small amount of powder for an effective dose
  • Dissolves easily in water or other liquids
  • Very affordable


  • It has an unpleasant taste
  • Packaging can lead to spills and contamination

Best L-Theanine Capsules For The Money

Capsules are a convenient way to take l-theanine supplements, but they can get expensive. However, some l-theanine capsules come at a reasonable price compared with others but still offer the benefits of l-theanine as much as the most popular name brands.

Doctor's Best L-Theanine
Best capsules for money

#6 Doctor’s Best L-Theanine

For l-theanine capsules that are potent, pure, and tested, and available at a reasonable price, look no further than Doctor’s Best L-Theanine.

Many people prefer L-theanine in capsule form because each dose of l-theanine is measured out, making it much easier to find the proper dosage and control the effects you want.

Doctor’s Best L-Theanine is an affordable bottle of 90 quality l-theanine capsules that contain 150 mg each.

The Doctor’s Best brand is transparent, has exemplary customer service, and other reliable supplements for well-rounded support. Their l-theanine supplements are no exception and can help you focus and concentrate and eliminate nagging anxiety.


  • Quality supplementation for a low price
  • Vegan and vegetarian friendly
  • Great way to support your existing stack


  • Does not last as long as some of the best l-theanine supplements
  • Large capsule size
  • Have a funny smell

How We Decide The Best Pick: What To Look For?

You may wonder how we chose the best l-theanine supplements on this list. We took several factors into account to ensure we picked the absolute best l-theanine supplements for a unique ability, overall health, and cognitive function.

Supplement Type & Form

The type of supplement and the form of l-theanine played a big role in our decision to rank each product.

Suntheanine is formulated to isolate and purify the compound, while l-theanine is an amino acid derived directly from green tea leaves. While both types offer comparable effects of l-theanine, we gave a slight edge to the purest form, which is Suntheanine.

For the categories that did not specify the forms, like powder, pill, or capsule, we looked at how the difference altered the benefits of l-theanine.

The two forms are both excellent for different purposes and durations (1). Therefore, while comparing suntheanine and l-theanine, neither option was objectively better for general purposes, and the other factors came into play.

Finally, the overall combination of ingredients had to be taken into consideration. While there are plenty of fantastic pure l-theanine options, blends of complementary ingredients often improve quality or offer other benefits that l-theanine does not provide on its own.

Still, it depends on the effects of l-theanine that you are looking for.


Every supplement offers exceptional support for different purposes, which is essential for choosing the best l-theanine supplements.

We looked at how well the supplementation could produce the targeted effect for the categories that specify a particular outcome.

L-theanine helps to promote several beneficial properties. For example, some are better for a relaxed mood and decrease anxiety or depression, while others increase brain health and learning performance.

For the overall best l-theanine supplements, we looked for a broader range of aspects. The best options provide an alert calmness, ease worries and tension, feel good, and enhance learning and memory.

We also considered supplements that combine complimentary ingredients that improve the intensity of different benefits, like encouraging sleep, promoting an alert state, and helping to calm the body and mind (2).

For example, caffeine will increase alertness, while bacopa monnieri will influence the sense of calm focus.

The best l-theanine supplements fulfill the purpose, with every ingredient playing a role in the overall feeling. Therefore, there should not be any filler ingredients that do not suit the purpose of the supplement.


Obviously, you look for a supplement that works and doesn’t waste your time and money, and we know that some products work much better than others since they can offer clean feelings without many or any negative effects.

The best way to see how effective each product is is to look at the company’s claims because the claims define the purpose that consumers are looking for.

We determine how well an l-theanine product works with our testing and look at each claim or desired effect. Then we can see if the product is effective for that benefit.

It is also essential to look at other things that can impact effectiveness, like slow or fast onset, duration, and how well a tiny or higher dose works.

We also look at side effects because they can hamper the ability to achieve desired results. If a product is effective but also causes numerous side effects, it loses points for effectiveness.

For example, a product that effectively increases alertness may do what it claims to, but if it causes insomnia, it cannot remain effective, especially when used close to sleep time.


Purity is also crucial for several different reasons. If a supplement has fillers, artificial colors, artificial flavors, or useless compounds, you will have to put more compounds in your body to achieve identical effects.

Not only that, but these types of things can affect absorption rate or ability to cross the blood-brain barrier as well, meaning that the l-theanine will not work as well.

Contamination, preservatives, and additives can also be responsible for illnesses or adverse reactions. But, again, this can raise the risk for a new user, even with a small dosage.

However, a smaller dosage will be sufficient for the purest options, which means less to be consumed for the results you want. Finally, Suntheanine is the purest form of l-theanine available, so it has a slight edge.


Finally, the overall price of each option is considered. If one product is better in terms of benefits but costs way more than it should, that will lower it on our list.

Conversely, an option that provides significant results for a low price will be in contention as long as it does well with the other factors.

The overall price is not the best way to judge supplements as well. So instead, we compare the cost to the mg of l-theanine and other compounds in each product to determine whether or not it is a good value.

We believe every option on our list is worth the money because they provide results deserving the price tag.


L-theanine can be a superb choice for nootropic benefits, brain health, calmness, and moderate occasional stress levels.

It is a popular and capable option for manual laborers, athletes, stressed mothers, and white-collar workers because it offers a wide range of physical and mental effects.

Making a verdict, Mind Lab Pro is the best stack with l-theanine you can buy. In addition, it is the only supplement on our list that offers complimentary ingredients designed for every facet of brain benefits.

Not only is it effective for its purposes, but it also comes at a reasonable price.