My evenings have completely changed
I used to be useless after 7pm. Now I have energy into the evenings and actually enjoy time with my family rather than just surviving until bedtime. Stack has genuinely changed my quality of life.
Nour M.
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Amino Acid200mg
Theanine
CALM FOCUS WITHOUT THE DROWSINESS
Dairy freeGluten freeSoy freeGMO free
$6.99/mo
30-day supply
Key Benefits
1
Promotes calm focus without drowsiness
2
Supports relaxation and stress resilience
3
May improve sleep quality
4
Enhances alpha brain wave activity
Recommended Dose
200mg
Take one 200mg capsule daily. For calm focus, take in the morning or early afternoon (pairs excellently with coffee or tea). For sleep support, take 30-60 minutes before bed. Theanine is non-habit-forming and does not cause daytime drowsiness.
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3rd Party Tested
🩺
Doctor Formulated
🛡️
cGMP Certified
The Details
Why you'll love it
Ever wonder why a cup of green tea feels so different from coffee, even though both contain caffeine? The secret is L-Theanine. This amino acid, found almost exclusively in tea leaves, crosses the blood-brain barrier and promotes alpha brain wave activity — the frequency associated with calm, focused attention. It's the state of mind you experience during meditation or creative flow.
Theanine works beautifully on its own for stress and anxiety relief, but it truly shines when paired with caffeine. Research shows the combination improves attention, reaction time, and cognitive performance more than either compound alone — while theanine takes the jittery edge off caffeine. It's focused energy without the crash.
At bedtime, theanine supports sleep quality not by sedating you but by calming the mental chatter that keeps you awake. Studies show it reduces resting heart rate, lowers stress markers, and helps people fall asleep faster by promoting relaxation. It's remarkably versatile: take it in the morning for focused calm, pair it with coffee for clean energy, or take it at night for better sleep.
Research
Clinical Evidence
Key studies supporting Theanine, from peer-reviewed journals.
2
L-theanine with caffeine boosts alertness; alone it promotes calm
Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis — 2014
3
L-theanine at 200-400 mg/day helps reduce stress and anxiety
The effects of green tea amino acid L-theanine consumption on the ability to manage stress and anxiety levels: a systematic review — 2020
Study titles are simplified for readability. Provided for informational purposes — not medical advice.
Transparency
What's Inside
Third-Party Tested
Every batch is independently tested by ISO-17025 accredited labs for purity, potency, and contaminants.
Doctor Formulated
Designed by healthcare professionals using evidence-based research and clinical expertise.
cGMP Certified
Manufactured in cGMP & UL certified, FDA-registered facilities with a flawless inspection record.
As with any natural health product, consult your healthcare practitioner. Store in a cool, dry place. Keep out of reach of children. Discontinue use immediately if you experience an adverse event.
What people say
changed my whole routine tbh
used to take like 5 different supplements every morning and always forgot at least two of them. now i take one stack pack and that's it. so much simpler. and the results are actually better. wild.
Hazel B.
The value proposition is actually excellent
I calculated what I was spending on separate supplements, gym supplements, and energy drinks before Stack.
Tim A.
Simple, smart, and it actually works
The packaging is some of the nicest I've seen in wellness. But beyond aesthetics, the product delivers. My energy throughout the day is more stable and I'm recovering faster from workouts. I was genuinely skeptical.
Ashley N.
The inflammation reduction has been significant
I suffer from low-grade chronic inflammation and it affects everything - energy, mood, joint comfort. Stack's personalized formula has noticeably reduced these symptoms over three months. The targeted approach is clearly more effective than generic options.
Eric T.
My husband noticed before I did
About six weeks in my husband said I seemed more like myself - more energy in the evenings, less irritable, sleeping better. I hadn't even consciously registered how much had changed until he said it.
Amara S.
Personalized for you
Not sure if Theanine is right for you?
Take our 2-minute Health Assessment and let our AI build your personalized stack — every supplement chosen for your specific goals.
Take the Health AssessmentProduct images are for illustrative purposes and may not represent actual packaging.
