Theanine
Description
Theanine is a unique amino acid that is a derivative of glutamic acid and is most prominently found in green and black tea leaves. Unlike other amino acids, L-Theanine is not commonly incorporated into proteins. Its primary mechanism involves crossing the blood-brain barrier to influence brain activity, particularly by increasing alpha brain wave activity, which is associated with a state of 'wakeful relaxation'. By modulating neurotransmitters such as GABA, dopamine, and serotonin, Theanine helps to reduce feelings of stress and anxiety while improving focus and concentration. This leads to a state of calm alertness, making it a popular supplement for those seeking to enhance cognitive performance and manage daily stressors without the sedative effects often associated with other relaxation aids. Often consumed in tea or as a dietary supplement, Theanine is also valued for its potential to improve sleep quality by promoting relaxation before bedtime. It is generally well-tolerated with a low incidence of side effects, making it a safe choice for many individuals looking to support mental well-being and cognitive function.
Sources
Green tea (Camellia sinensis)Black tea (Camellia sinensis)Some mushrooms (e.g., Bay Bolete)
Cheapest Theanine supplements
Best Theanine supplements
Value Theanine Supplements
Optimal Dosage
Minimum100 mg
Maximum400 mg
Safety & Toxicity
Goals
Cognitive Support
Impact
High effect
Typical dose:100–200 mg
Found in green tea, L-Theanine is an amino acid that modulates neurotransmitters like GABA and dopamine. It is highly effective at taking the 'edge' off stimulants like caffeine, resulting in smooth, focused energy and reduced anxiety.
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Mental Focus
Impact
High effect
Typical dose:100–200 mg
Found primarily in green tea, L-Theanine modulates neurotransmitters like dopamine and GABA. It provides a non-drowsy relaxation effect that can mitigate the jitteriness of caffeine, leading to a synergistic improvement in smooth, sustained mental focus.
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Productivity Boost
Impact
High effect
Typical dose:100–400 mg
L-Theanine is an amino acid that can cross the blood-brain barrier and increase alpha brain wave activity, which is associated with a state of 'relaxed wakefulness'. It can modulate neurotransmitters like GABA and dopamine, improving focus and attention without sedation.
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Sleep Support
Impact
High effect
Typical dose:100–400 mg
L-Theanine, an amino acid found in green tea, is known for its ability to induce a state of 'calm alertness' by increasing alpha brain wave activity. It helps quiet a racing mind and reduces stress, addressing common barriers to falling asleep. It does not act as a sedative but rather facilitates the transition into sleep.
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Stress Relief
Impact
High effect
Typical dose:100–200 mg
This amino acid, commonly found in green tea, can cross the blood-brain barrier and influence neurotransmitter levels. It enhances GABA, serotonin, and dopamine, leading to a quick-acting reduction in mental and physical stress while improving focus.
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Interactions
Positive Interactions
Caffeine
Enhances cognitive benefits (focus, attention) and mitigates potential side effects of caffeine like jitters and anxiety, promoting 'calm alertness'.
Magnesium
May synergistically support relaxation and neurological function.
GABA
Theanine can influence GABA levels in the brain, potentially enhancing its calming and anxiolytic effects.
Ashwagandha
Both are adaptogens known for stress reduction; combining them may have synergistic effects on promoting relaxation and mental well-being.
Melatonin
By promoting relaxation, Theanine may indirectly support the sleep-inducing effects of melatonin.
Negative Interactions
Hawthorn
May lead to an additive mild hypotensive effect, particularly in individuals prone to low blood pressure, as both can mildly lower blood pressure.
Valerian
May increase sedative effects and potentially an additive mild blood pressure-lowering effect if taken together, especially in sensitive individuals.
Recommended products
Value 
Smart Caffeine with L-Theanine
NS Natural Stacks
Theanine: 200 mg
A well-formulated L-Theanine and Caffeine stack for smooth energy and focus, offering good value and high customer satisfaction.
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NOW
Theanine: 285 mg
A high-dose liquid L-Theanine option from NOW, offering good value and versatility for various calming and focus-related goals.
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Source Naturals
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This formula combines L-Theanine, GABA, Taurine, Magnesium, and Holy Basil to support relaxation, a balanced mood, and restful sleep without significant drowsiness.
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Jarrow Formulas
Theanine: 200 mg
A Jarrow Formulas L-Theanine supplement, offering 200mg per veggie cap for supporting calm and focus, with substantial customer feedback.
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Day Starter
Source Naturals
Theanine: 200 mg
This product combines caffeine from green tea with L-Theanine to offer a noticeable energy lift and improved focus, aiming for smooth alertness without excessive nervousness.
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Anxiety & Stress Relief
Nature's Bounty
Theanine: 200 mg
This supplement offers a focused blend of Ashwagandha and L-Theanine, providing support for stress relief and a more relaxed state for daily well-being at an appealing price.
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Pure Encapsulations
Theanine: 200 mg
A basic L-Theanine product at a standard dose, but an extremely high price per serving and very low customer reviews severely limit its value.
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Theanine: 200 mg
An excellent value L-Theanine product at a standard dose, offering an exceptionally low price per serving and very high customer satisfaction.
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NS
Theanine: 400 mg
This product features a blend of L-Theanine, Ashwagandha, and B6, which may contribute to relaxation and mood support, but the inclusion of an undisclosed proprietary blend impacts its clarity and value.
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Pulse Fruit Punch
Legion
Theanine: 350 mg
Pulse Fruit Punch is a high-stimulant pre-workout supplement packed with ingredients to support energy, focus, and athletic performance during intense workouts, plus added electrolytes.
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Neuro-T
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Theanine: 250 mg
This formula blends stimulating ingredients with calming herbs and cognitive enhancers, aiming to support focused energy and mental clarity.
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Focus-R
LifeSeasons
Theanine: 250 mg
This complex formula blends energizing compounds with calming herbs and cognitive enhancers to support focused attention and mental performance.
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L-Theanine 200 mg
Advance Physician Formulas
Theanine: 200 mg
An excellent value L-Theanine product at a standard dose, featuring a very low price per serving and strong customer satisfaction.
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L-Theanine 200 mg
Health Thru Nutrition
Theanine: 200 mg
A budget-friendly L-Theanine supplement from Health Thru Nutrition, offering 200mg of green tea-derived PhytoSure L-Theanine in a vegecap, but with almost no customer feedback.
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Double Strength L-Theanine 200 mg
NOW
Theanine: 200 mg
A NOW supplement featuring 200mg L-Theanine and 100mg Inositol per capsule, designed for enhanced mood and nervous system support at a good value.
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Triple Action Sleep
Solgar
Theanine: 200 mg
This tablet offers a powerful combination of 10mg melatonin, 200mg L-theanine, and a 50mg herbal blend in a value-sized pack, aiming for comprehensive sleep and relaxation.
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L-Theanine 150 mg
Doctor's Best
Theanine: 150 mg
A Doctor's Best L-Theanine supplement, offering 150mg per veggie cap at an excellent price, backed by extensive positive customer feedback.
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Sleep Regimen 3-in-1
NOW
Theanine: 200 mg
This product combines L-Theanine, 5-HTP, and Melatonin in a single capsule, aiming to support relaxation and healthy sleep patterns effectively.
Value 
Double Strength L-Theanine 200 mg
NOW
Theanine: 200 mg
A highly affordable L-Theanine supplement at 200mg, with added Inositol for mood support, making it a strong value pick from a popular brand.
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L-Theanine 200 mg
California Gold Nutrition
Theanine: 200 mg
An incredibly affordable L-Theanine supplement at an effective 200mg dose, offering excellent value and broad customer approval for basic calm and focus.
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Theanine
Thorne
Theanine: 200 mg
A premium Suntheanine L-Theanine supplement from Thorne, delivering 200mg per capsule for calm and focus, backed by a strong brand reputation but at a high price.
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L-Theanine
Pure Encapsulations
Theanine: 400 mg
A high-dose L-Theanine product, but its extremely high price per serving and limited customer reviews make it a poor value.
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CatecholaCalm
Designs for Health
Theanine: 200 mg
This supplement offers a comprehensive blend of B vitamins, magnesium, amino acids, and herbal extracts like Valerian and Ashwagandha, supporting a calm mood, stress relief, and mental function.
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L-Theanine 200 mg
Vital Nutrients
Theanine: 200 mg
A simple L-Theanine product at a common dose, but the price per serving is a bit high and customer feedback is limited.
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L-Theanine 200 mg Double Strength
Swanson
Theanine: 200 mg
A reliable L-Theanine supplement featuring 200mg of branded Suntheanine in a veggie cap, offering good quality at a reasonable price.
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Energy + Focus
ZHOU
Theanine: 200 mg
A ZHOU supplement that combines 200mg L-Theanine with 100mg natural caffeine, offering smooth energy and enhanced focus.
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Suntheanine L-Theanine 125 mg
Natural Factors Stress-Relax
Theanine: 250 mg
A capsule-based L-Theanine product featuring the branded Suntheanine, providing 250mg per dose for calm and focus.
Product stats
Price per product
Average$31.08
Median$26.32
Price per serving
Average$0.79
Median$0.58
Price per 100 mg
Average$0.37
Median$0.29
Price distribution
Price per serving distribution
Price per 100 mg
Reference amount: 100 mg
Paired ingredients