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Woman in olive activewear standing with hands together in a brick-walled studio. L-Theanine outcomes and benefits, Calm Without Fatigue: promotes relaxed alertness by supporting alpha brainwave activity; reduces mental tension and promotes clarity by regulating GABA and serotonin. (280 chars)
Momentous L-Theanine bottle on a black background, promotes calm focus without fatigue and supports a relaxed mind for sleep, dietary supplement, 60 capsules, NSF Certified for Sport. (182 chars)
Close-up of a capsule on a surface. Text reads: “How it works. Supports a calm, focused state by increasing alpha brain wave activity associated with relaxed alertness. Helps regulate GABA and serotonin, reducing tension and promoting clarity without sedation.”
Versatile stress support. Daytime: helps turn down the
How to use L-Theanine: take 1 capsule daily; for calm focus, take anytime of day; for sleep support, take 30-60 minutes before bed. Single white capsule on a warm tan background. (177 chars)
Hand reaching for white L-Theanine capsules scattered on a tan surface, with a five-star verified customer quote from Lance:
Momentous L-Theanine, same great formula, fresh new look. Side-by-side comparison of the previous black bottle labeled Sleep & Cognitive Support, 60 capsules, and the new bottle labeled promotes calm focus without fatigue and supports a relaxed mind for sleep, dietary supplement, 60 capsules, NSF Certified for Sport. (315 chars)
L-Theanine Supplement Facts panel: serving size 1 capsule, 60 servings per container, L-Theanine 200mg. Other ingredients rice flour, hypromellose (capsule), magnesium stearate, silica. NSF Certified for Sport, The Momentous Standard, gluten free, GMO free, vegan. (261 chars)
Woman in olive activewear standing with hands together in a brick-walled studio. L-Theanine outcomes and benefits, Calm Without Fatigue: promotes relaxed alertness by supporting alpha brainwave activity; reduces mental tension and promotes clarity by regulating GABA and serotonin. (280 chars)
Momentous L-Theanine bottle on a black background, promotes calm focus without fatigue and supports a relaxed mind for sleep, dietary supplement, 60 capsules, NSF Certified for Sport. (182 chars)
Close-up of a capsule on a surface. Text reads: “How it works. Supports a calm, focused state by increasing alpha brain wave activity associated with relaxed alertness. Helps regulate GABA and serotonin, reducing tension and promoting clarity without sedation.”
Versatile stress support. Daytime: helps turn down the
How to use L-Theanine: take 1 capsule daily; for calm focus, take anytime of day; for sleep support, take 30-60 minutes before bed. Single white capsule on a warm tan background. (177 chars)
Hand reaching for white L-Theanine capsules scattered on a tan surface, with a five-star verified customer quote from Lance:
Momentous L-Theanine, same great formula, fresh new look. Side-by-side comparison of the previous black bottle labeled Sleep & Cognitive Support, 60 capsules, and the new bottle labeled promotes calm focus without fatigue and supports a relaxed mind for sleep, dietary supplement, 60 capsules, NSF Certified for Sport. (315 chars)
L-Theanine Supplement Facts panel: serving size 1 capsule, 60 servings per container, L-Theanine 200mg. Other ingredients rice flour, hypromellose (capsule), magnesium stearate, silica. NSF Certified for Sport, The Momentous Standard, gluten free, GMO free, vegan. (261 chars)
4.8
Rated 4.8 out of 5 stars
229

L-Theanine

60 Servings Per Container: $0.49/Serving

Supports relaxation, mental clarity, and stress response—helping you stay calm and focused without drowsiness

  • Promotes calm, focused mental clarity
  • Helps reduce acute stress without brain fog
  • Supports relaxation and sleep quality
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"Within a week of using L-Theanine I was falling asleep faster than I have for years. I'm a fan!"

Ami (Verified Customer)

"L-Theanine has been a game changer for my sleep. There’s absolutely zero drowsiness when I wake in the morning."

Sharon (Verfied Customer)

"I take one at bedtime, within minutes, zonked out. This assures a quick and effective zonk."

Lance (Verfied Customer)

Calm, Focused Mental Performance.

L-Theanine is a naturally occurring amino acid that promotes relaxation without sedation—helping you stay clear, composed, and focused under stress or wind down for sleep.

Calm, Clarity, and Control.

L-Theanine helps reduce acute stress while supporting a calm, focused mental state—so you can stay composed without losing your edge. By promoting relaxation without drowsiness, it allows you to think clearly, manage pressure more effectively, and maintain steady focus throughout the day. Whether you're navigating a demanding schedule or winding down at night, L-Theanine supports a more balanced, controlled state of mind.

L-Theanine works by supporting the brain’s natural relaxation pathways without impairing alertness.

It increases alpha brain wave activity—associated with a calm, focused mental state—and helps regulate key neurotransmitters like GABA and serotonin, which influence mood, stress response, and mental clarity.

By reducing neuronal excitability, L-Theanine promotes a state of relaxed alertness, making it effective for both daytime focus and nighttime wind-down.

Flexible, Daily Support

Take 1 capsule (200mg) daily.

  • For focus and stress: take anytime during the day
  • For sleep: take 30–60 minutes before bed


Consistent daily use is recommended for best results.

L-Theanine 200mg per serving

Other Ingredients: Rice Flour, Hypromellose (Capsule), Magnesium Stearate, Silica

GMO Free, Gluten Free, Vegan.

When to Use
Daily, or as needed for stress, focus, or sleep support.

Onset Time
Some effects may be felt within hours, with more noticeable benefits after consistent use over several days.

Expected Results

  • Increased relaxation without drowsiness
  • Improved focus and mental clarity
  • Easier transition to sleep and better sleep quality

Frequently Asked Questions

L-Theanine is an amino acid naturally found in green tea. As a dietary supplement, it is commonly used to support relaxation, stress management, and calm focus without causing significant drowsiness.

L-Theanine is used to support relaxation, stress management, and mental clarity. Many people take it to promote a balanced mental state without sedation.

Yes. L-Theanine is commonly taken daily when used as directed. Many individuals incorporate it into their routine to support ongoing stress management and focus.

L-Theanine is known for promoting relaxation without significant drowsiness at recommended serving sizes. Many people use it to support a calm, focused state while remaining mentally alert.

Individual responses may vary depending on dosage and timing.

Yes. L-Theanine is often combined with caffeine to support focused energy. While caffeine promotes alertness, L-Theanine may help promote a smoother, more balanced experience.

Yes, L-Theanine is often used to support sleep quality by promoting relaxation and reducing mental tension. It does not act as a sedative, but may help create a calmer state that supports easier sleep onset and more restful sleep.

L-Theanine is commonly taken alongside other supplements, including caffeine, magnesium, and ingredients that support focus or sleep. Many people include it as part of a broader daily routine.

If you are taking medications or have specific health concerns, it is recommended to consult with a healthcare professional before use.

Yes. Momentous L-Theanine is NSF Certified for Sport®, meaning every batch is independently tested for purity, potency, and label accuracy. NSF Certified for Sport® also confirms the product is tested for banned substances, making it suitable for drug-tested athletes.

4.8
Rated 4.8 out of 5 stars
Based on 229 reviews
94%would recommend this product
Reviews Summary
Customers say this supplement significantly improves their sleep quality and helps them fall asleep faster. Many reviews mention waking up feeling refreshed without morning grogginess, unlike other sleep aids. Users frequently combine it with magnesium or other supplements for enhanced effects. Common feedback includes its calming properties and ability to quiet racing thoughts before bedtime. While most praise its effectiveness for staying asleep through the night, one reviewer noted it didn't work for them. Many appreciate the quality and third-party testing, with several mentioning improved sleep metrics on tracking devices.
Customers Talked About
229 reviews
  • MS
    Maria S.
    Verified Buyer
    22 seconds ago
    Rated 5 out of 5 stars
    Dr. Stacy Sims was right!

    I started my nightly L-Theanine regimen (with Mag L-Threonate) when I came across a post Dr. Sims did about sleeping. Being postmenopausal, I have had major issues with sleep and wanted something natural vs. a pharmaceutical sleep aid. I am so thankful I came across that post - it has changed my fitness journey - which doesn't exist without a good sleep pattern. I cannot live (or sleep) without Momentous L-Theanine, Mag L-Threonate, and Momentous Creatine.

  • FW
    Fernanda W.
    Verified Buyer
    2 days ago
    Rated 5 out of 5 stars
    Thankful for finding this product!

    I had tried L-Theanine previously in another product and it made me feel a bit off balance. I was hesitant to try it again. However the science convinced me to give it another try. I’m happy to say that Momentous’ product has provided a much better result for me. I’m learning that while it is suggested that you take it 30-60 min before bed for best sleep, for me, through a bit of trial and error, I have found it works best when I take it in late afternoon. My sleep has in fact improved and I wake feeling more rested, which was the goal:)

  • MP
    Martina P.
    Verified Buyer
    Product Standouts Ease of Use, Results, Trust and Transparency, Value for Money
    2 weeks ago
    Product Standouts Ease of Use, Results, Trust and Transparency, Value for Money
    Rated 5 out of 5 stars
    In the evening

    In the evening it helps me wind down, but it doesn’t knock me out. Effect is mild and lasts a few hours. No real side effects for me.

  • SV
    Svetlana V.
    Verified Buyer
    Product Standouts Ease of Use, Results, Value for Money, Trust and Transparency
    4 weeks ago
    Product Standouts Ease of Use, Results, Value for Money, Trust and Transparency
    Rated 5 out of 5 stars
    A favorite part of my nighttime routine

    I take this about 45–60 minutes before bed and really like how it helps me wind down without making me feel groggy or overly sleepy. It’s become such an easy part of my nighttime routine. Simple, effective, no side effects for me, and another Momentous supplement I trust for quality and testing.

  • CG
    Cindy G.
    Verified Buyer
    Product Standouts Ease of Use
    4 weeks ago
    Product Standouts Ease of Use
    Rated 5 out of 5 stars
    Sleep

    I use L-Theanine for sleep. I love it and it works amazing. My sleep is great.