• L - Theanine - BioVitals
  • L - Theanine - BioVitals
  • L - Theanine - BioVitals
  • L - Theanine - BioVitals
  • L - Theanine - BioVitals
  • L - Theanine - BioVitals
  • L - Theanine - BioVitals
  • L - Theanine - BioVitals

L-Theanine 400 mg

4.8/5 stars
4.8/5

|788 Customer reviews

Joshua P. Light, M.D., Chief Medical Advisor

With piperine for absorption, BioVitals’ L-Theanine helps reduce stress and mental tension while keeping focus clear, working best as quiet daily support.

L-Theanine 400 mg

4.8/5 stars
4.8/5

|788 Customer reviews

FocusSleepStressCalmClarityRelaxation

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Joshua P. Light, M.D., Chief Medical Advisor

With piperine for absorption, BioVitals’ L-Theanine helps reduce stress and mental tension while keeping focus clear, working best as quiet daily support.

Benefits

L-Theanine 400 mg is a natural amino acid from tea leaves that helps calm your mind without making you drowsy. You get better mental clarity and sharper focus while keeping stress in check for hours.

Most people don't get nearly enough from tea alone. Our 400 mg dose delivers the clinically studied amount in one capsule, and it’s the same amount used in research that showed real results. You won't feel jittery or tired. You'll think more clearly.

Ingredients

L-Theanine 400 mg
This is the same dose used in the clinical research that showed real results for stress and focus.

Clean Formula
Pure L-Theanine extracted from tea leaves without fillers or artificial additives.

Third-Party Tested
Every batch gets verified for purity and potency so you know you're getting what the label says.

How to Use

Take one capsule daily. Most people take it in the morning or early afternoon. If you want sleep support, take it 30-60 minutes before bed.

You'll likely notice something within 30-60 minutes. The effects get stronger with regular use.

Subscription Policy

Subscribe and get up to $30 in free surprise gifts with every delivery, plus free shipping on orders over $50.

You can pause, skip, or cancel anytime through your account without commitments or hassle.

Every order is backed by our 90-day money-back guarantee. If it doesn't work for you, we'll refund your purchase.

Feel The Difference in Your Mental Performance

Reduces Stress & Tension

Helps calm your mind during stressful situations so you can think clearly and respond better.

Improves Focus & Clarity

Supports sustained attention and mental sharpness throughout your day without crashes.

Supports Better Sleep

Helps quiet racing thoughts before bed so falling asleep feels easier and more natural.

Calm Without Drowsiness

You stay alert and productive. This isn't a sedative, it helps you feel balanced and present.

Handles Daily Pressure

Makes it easier to perform under stress without feeling overwhelmed or mentally drained.

Works Fast

Most people notice a difference within 30-60 minutes. Effects get stronger with regular use.

How L-Theanine Works

01

Reaches the brain quickly

L-Theanine reaches your brain quickly and increases calming neurotransmitters like GABA and serotonin.
02

Creates a meditation-like state

Promotes the same brain wave pattern you get during meditation: relaxed but awake and focused.
03

Keeps the mind balanced

Reduces overactive glutamate signaling, which helps your mind stay calm under pressure instead of spinning out.

Simple & effective ingredients

Pure L-Theanine at the dose that works in clinical research.

L-Theanine 400 mg

This is the amount used in studies showing real results for stress, focus, and sleep. Most supplements only give you 100-200 mg, which sits below the effective range for adults dealing with chronic stress or mental fatigue.

L-Theanine 400 mg

Clean Formula

Pure L-Theanine extracted from tea leaves, without fillers or artificial additives that cause bloating.

Clean Formula

Third-Party Tested

Every batch gets tested by an independent lab to verify purity and potency, so you're getting exactly what's on the label.

Third-Party Tested

Compare Quality, Sourcing & Formulation

BioVitals BioVitals
OTHER BRANDS OTHER BRANDS
400 mg Clinically Studied Dose
Pure L-Theanine Extract
Fast Absorption
Third Party Testing
Certifications
Good User Reviews
Good Value
90 Day Money Back
Subscription Program
Science Backed Formula

Science-Backed Formula

3rd LAB Tested
9 Allergens Free
NON GMO
US Quality Standards
Vegan
Gluten Free

The Science Behind L-Theanine

L-Theanine has been studied for decades, with consistent findings around stress reduction and cognitive performance.

Research shows it may help support:

• Calm mental state without drowsiness

• Improved focus and mental clarity

• Healthy stress response

• Reduced tension and anxious feelings

• Better sleep quality


Our formula uses 400 mg because that's the dose used in clinical research for measurable results. Most products contain 100-200 mg, which delivers weaker effects.


Individual results may vary.

Scientific References:

Williams JL, Everett JM, D'Cunha NM, et al. (2019). Psychotropic effects of L-theanine and its clinical properties. Pharmacological Research.[1]

Hidese S, Ogawa S, Ota M, et al. (2019). Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients.[2]

AlphaWave® L-Theanine (400 mg/day) study with healthy adults with moderate stress for 28 days. Neurology and Therapy (2024).[5][10]

Bulman A, D'Cunha NM, Marx W, et al. (2025). The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis. Sleep Medicine Reviews.[2]

Haskell CF, et al. (2008). The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness. Nutritional Neuroscience.[2]

Kelly SP, et al. (2008). L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance. Journal of Nutrition.[3]

93% Reported feeling calmer during stressful situations
89% Noticed improved focus and mental clarity
91% Experienced better sleep quality and easier mornings

What Our Customers Say

  • Tyler, 37

    “I used to get tense and anxious out of nowhere. Taking L-Theanine has made a real difference. I feel calmer and more in control throughout the day.”

    Tyler, 37

    Verified customer
  • Anne, 41

    “The brain fog cleared up and I can finally push through the afternoon without losing focus.”

    Anne, 41

    Verified customer
  • Bethany, 29

    “This really helps me wind down at night without feeling groggy the next morning, I actually wake up refreshed now.”

    Bethany, 29

    Verified customer

Frequently Asked Questions

When will I notice results?

Most people notice effects within 30-60 minutes of taking it. The benefits build with regular use.

How should I take it?

Take one capsule daily, usually in the morning or early afternoon. If you're using it for sleep support, take it 30-60 minutes before bed.

Is it safe for daily use?

Yes. L-Theanine is well-tolerated and safe for long-term daily use.

Will this make me sleepy?

No. L-Theanine promotes relaxation without causing drowsiness. You stay alert and focused.

Can I take this with coffee?

Yes. L-Theanine pairs well with caffeine. It smooths out the jitters while keeping you focused.

Do you offer a guarantee?

Yes. 90-day money-back guarantee. If you're not satisfied, we'll refund your purchase.

Get Your Focus and Calm Back
4.8/5 stars
4.8/5

|788 Customer reviews

Get Your Focus and Calm Back

Start feeling more in control with L-Theanine 400mg

Free Shipping Over $50
Safe & Secure Checkout
90-Day Money-Back Guarantee

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