Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing evidence
Evidence status
Verified independent evidence
Manufacturer statement
Product page states "Third-Party Lab Tested Quality" and "3rd Party Lab Tested & Verified"; the COA for L-Theanine Capsules 200mg (Lot LTHCS1082426) shows identity, potency, and heavy metals results with pass/fail outcomes.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing evidence
Evidence status
Recognised certification
Manufacturer statement
NSF Certified for Sport registry page for Momentous L-Theanine: "Brand Momentous ... Product Form Capsule ... Package Size 60 capsules ... Website www.livemomentous.com" and the page title "Official Certified for Sport® Product Certification Listing" confirms this specific product is certified.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing evidence
Evidence status
Testing claimed
Manufacturer statement
Manufacturer site uses generic quality/testing language only: "Trusted Ingredients" / "Laboratory Tested" and "We put our products to the test, ensuring maximum potency from each formula we produce." No independently verifiable COA, lab report, or certification for this specific L-Theanine product was found.
Compare actual L-theanine mg per day. Tea extract, caffeine and other actives are kept separate, and a branded-ingredient claim is provenance, not automatic superiority. The amount is what the label states, not a dose-adequacy rating. Where directions give a range, the range is shown and daily cost uses the low end (no directions: one unit a day). Read the dose guide ↓
Product page states "Third-Party Lab Tested Quality" and "3rd Party Lab Tested & Verified"; the COA for L-Theanine Capsules 200mg (Lot LTHCS1082426) shows identity, potency, and heavy metals results with pass/fail outcomes.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NSF Certified for Sport registry page for Momentous L-Theanine: "Brand Momentous ... Product Form Capsule ... Package Size 60 capsules ... Website www.livemomentous.com" and the page title "Official Certified for Sport® Product Certification Listing" confirms this specific product is certified.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site uses generic quality/testing language only: "Trusted Ingredients" / "Laboratory Tested" and "We put our products to the test, ensuring maximum potency from each formula we produce." No independently verifiable COA, lab report, or certification for this specific L-Theanine product was found.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nutricost product page states: “Third-Party Tested †” and “Nutricost products are tested by an independent, accredited lab to help verify that what’s on the label is what’s in the bottle.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Sports Research product page says "Third Party Tested Certified" and "Third Party Tested" for L-Theanine, but I did not find an independently verifiable registry or lab report for this specific product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
BulkSupplements' About page says: "Each supplement is tested by a 3rd party laboratory before distribution" and the homepage says: "Lab Tested for Purity — Each supplement is tested by a 3rd party laboratory". I did not find an independently verifiable COA or registry entry for this specific L-Theanine capsules product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site says: "Every raw material is tested for identity, purity, and potency upon arrival. We also perform rigorous laboratory testing on the finished batches to ensure they are free from contaminants and meet the strength listed on the label." The product page also says: "Every batch is thoroughly tested to ensure that our customers are getting exactly what it says on the label."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nutricost’s product page says “Third-Party Tested †” and “Nutricost products are tested by an independent, accredited lab to help verify that what’s on the label is what’s in the bottle.” I also checked NSF’s public registries and found no matching Nutricost L-Theanine product certification; the NSF Sport result I found was for a different brand (Momentous), not Nutricost.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Horbäach’s own site says the product is “Laboratory Tested” and that they “put our products to the test, ensuring maximum potency from each formula we produce.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site says "Laboratory Tested" and "We put our products to the test, ensuring maximum potency from each formula we produce" / "test each individual product to ensure it meets our strict Quality Assurance Standards."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Thorne product page states: "This product has been third-party tested and certified to verify what's in the package matches what's on the label and to confirm it contains no unsafe levels of contaminants, such as heavy metals, pesticides, and microorganisms." NSF’s own registry lists "Thorne® Theanine" under NSF/ANSI 173 - Dietary Supplements.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW Foods says its products undergo "over 31,000 analyses and tests each month" and that it "partner[s] with trusted third-party labs for independent verification"; its quality page also says Informed Sport products are tested for banned substances by LGC, but the L-Theanine 200 mg product page itself only shows GMP/non-GMO/halal/kosher-style claims and no product-specific third-party test or certification for this item.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Amazon listing and product images show "Non GMO Project Verified" and "Certified Gluten-Free"; Country Life's own product page also states "Country Life's first IGEN Non-GMO SKU is verified" and shows the NGPV badge. I independently checked the Non-GMO Project's own verification page/registry entry for the product family and found the registry page for Non-GMO Project Verified.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Jarrow’s Science page says: “Every batch. Every time. Raw materials are tested for identity, purity, and potency before production begins. Finished products are tested again. Our in-house analytical labs run full-spectrum analysis so nothing leaves our facility without verification.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW’s product page says the product is “certified by Intertek” only at the brand level via a general quality page, but the product-specific page for L-Theanine 100 mg itself only shows marketing/ingredient information and a GMP-facility statement; I did not find an independently verifiable certification or product-specific COA for this exact item.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Life Extension says: "We are happy to provide a summary of the reports we receive from the contract manufacturers and the independent laboratories that test both our raw materials and final products. We can do this for every supplement..." and the product page says: "Laboratory analysis confirms that theanine used in our formulation contains only the pure L-Theanine form of this amino acid."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW’s product page says the product is "Produced in a GMP facility" and NOW’s quality page says "NOW is audited and certified by Intertek as having met the Supplement Safety & Compliance Initiative (SSCI) benchmarks"; however, I did not find an independently verifiable certification or product-specific COA for this exact L-Theanine product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Solaray’s own quality page says: “We don’t just review supplier documents, we verify raw materials ourselves to ensure what’s on the label is exactly what’s in the bottle” and “With 580+ protocols, we confirm identity, potency, and purity, and screen for contaminants like heavy metals and pesticides.” The product page also says Solaray’s lab conducts testing and that the product is “Lab Verified” on Amazon, but I did not find an independently verifiable product-specific certificate or lab report for this exact L-Theanine product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Vital Nutrients’ own site says: “Vital Nutrients exceeds quality standards by testing every batch of each raw material and finished product to ensure our stringent specifications for authenticity, potency and purity are consistently upheld.” It also says: “The independent third-party lab testing Vital Nutrients conducts for heavy metals, aflatoxins, chemical solvents, and herbicides/pesticides/fungicides is in addition to those required by regulations.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Product page states "Third-Party Lab Tested Quality" and "3rd Party Lab Tested & Verified"; the COA for L-Theanine Capsules 200mg (Lot LTHCS1082426) shows identity, potency, and heavy metals results with pass/fail outcomes.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NSF Certified for Sport registry page for Momentous L-Theanine: "Brand Momentous ... Product Form Capsule ... Package Size 60 capsules ... Website www.livemomentous.com" and the page title "Official Certified for Sport® Product Certification Listing" confirms this specific product is certified.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site uses generic quality/testing language only: "Trusted Ingredients" / "Laboratory Tested" and "We put our products to the test, ensuring maximum potency from each formula we produce." No independently verifiable COA, lab report, or certification for this specific L-Theanine product was found.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nutricost product page states: “Third-Party Tested †” and “Nutricost products are tested by an independent, accredited lab to help verify that what’s on the label is what’s in the bottle.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Sports Research product page says "Third Party Tested Certified" and "Third Party Tested" for L-Theanine, but I did not find an independently verifiable registry or lab report for this specific product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
BulkSupplements' About page says: "Each supplement is tested by a 3rd party laboratory before distribution" and the homepage says: "Lab Tested for Purity — Each supplement is tested by a 3rd party laboratory". I did not find an independently verifiable COA or registry entry for this specific L-Theanine capsules product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site says: "Every raw material is tested for identity, purity, and potency upon arrival. We also perform rigorous laboratory testing on the finished batches to ensure they are free from contaminants and meet the strength listed on the label." The product page also says: "Every batch is thoroughly tested to ensure that our customers are getting exactly what it says on the label."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nutricost’s product page says “Third-Party Tested †” and “Nutricost products are tested by an independent, accredited lab to help verify that what’s on the label is what’s in the bottle.” I also checked NSF’s public registries and found no matching Nutricost L-Theanine product certification; the NSF Sport result I found was for a different brand (Momentous), not Nutricost.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Horbäach’s own site says the product is “Laboratory Tested” and that they “put our products to the test, ensuring maximum potency from each formula we produce.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site says "Laboratory Tested" and "We put our products to the test, ensuring maximum potency from each formula we produce" / "test each individual product to ensure it meets our strict Quality Assurance Standards."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Thorne product page states: "This product has been third-party tested and certified to verify what's in the package matches what's on the label and to confirm it contains no unsafe levels of contaminants, such as heavy metals, pesticides, and microorganisms." NSF’s own registry lists "Thorne® Theanine" under NSF/ANSI 173 - Dietary Supplements.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW Foods says its products undergo "over 31,000 analyses and tests each month" and that it "partner[s] with trusted third-party labs for independent verification"; its quality page also says Informed Sport products are tested for banned substances by LGC, but the L-Theanine 200 mg product page itself only shows GMP/non-GMO/halal/kosher-style claims and no product-specific third-party test or certification for this item.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Amazon listing and product images show "Non GMO Project Verified" and "Certified Gluten-Free"; Country Life's own product page also states "Country Life's first IGEN Non-GMO SKU is verified" and shows the NGPV badge. I independently checked the Non-GMO Project's own verification page/registry entry for the product family and found the registry page for Non-GMO Project Verified.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Jarrow’s Science page says: “Every batch. Every time. Raw materials are tested for identity, purity, and potency before production begins. Finished products are tested again. Our in-house analytical labs run full-spectrum analysis so nothing leaves our facility without verification.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW’s product page says the product is “certified by Intertek” only at the brand level via a general quality page, but the product-specific page for L-Theanine 100 mg itself only shows marketing/ingredient information and a GMP-facility statement; I did not find an independently verifiable certification or product-specific COA for this exact item.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Life Extension says: "We are happy to provide a summary of the reports we receive from the contract manufacturers and the independent laboratories that test both our raw materials and final products. We can do this for every supplement..." and the product page says: "Laboratory analysis confirms that theanine used in our formulation contains only the pure L-Theanine form of this amino acid."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW’s product page says the product is "Produced in a GMP facility" and NOW’s quality page says "NOW is audited and certified by Intertek as having met the Supplement Safety & Compliance Initiative (SSCI) benchmarks"; however, I did not find an independently verifiable certification or product-specific COA for this exact L-Theanine product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Solaray’s own quality page says: “We don’t just review supplier documents, we verify raw materials ourselves to ensure what’s on the label is exactly what’s in the bottle” and “With 580+ protocols, we confirm identity, potency, and purity, and screen for contaminants like heavy metals and pesticides.” The product page also says Solaray’s lab conducts testing and that the product is “Lab Verified” on Amazon, but I did not find an independently verifiable product-specific certificate or lab report for this exact L-Theanine product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Vital Nutrients’ own site says: “Vital Nutrients exceeds quality standards by testing every batch of each raw material and finished product to ensure our stringent specifications for authenticity, potency and purity are consistently upheld.” It also says: “The independent third-party lab testing Vital Nutrients conducts for heavy metals, aflatoxins, chemical solvents, and herbicides/pesticides/fungicides is in addition to those required by regulations.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
One-time purchase prices; delivery and conditional discounts excluded. Daily cost uses the recorded label serving. Comparison amounts are not personal dose recommendations. Unknown Prime eligibility is not treated as confirmed.
L-theanine forms and labels explained
Compare actual L-theanine mg first. Then distinguish isolated or tea-derived L-theanine, caffeine combinations, named raw materials and multi-ingredient blends.
L-theanine alone
Single-active formulation
Compare
L-theanine mg
Caffeine
None declared
Best match for standalone L-theanine evidence.
L-theanine from tea extract
Tea-derived source
Main dose
Actual L-theanine
Keep separate
Tea-extract mass
Do not treat total tea extract or tea-leaf equivalent as the L-theanine dose.
L-theanine plus caffeine
Combination formulation
Record
Both doses
Evidence
Combination-specific
Acute focus benefits from the combination cannot be attributed to L-theanine alone.
Named L-theanine ingredient
Trademarked raw material
Usefulness
Study traceability
Not automatic
Superior efficacy
Named ingredients still need finished-product quality evidence.
Multi-ingredient blend
Sleep, stress or focus blend
Compare
Each active separately
Avoid
Blend-mass dosing
Do not assign co-ingredient evidence to L-theanine.
L-theanine dose: study amounts, not a universal target
No FDA L-theanine Daily Value, RDA/AI or formal upper limit was identified in the official US sources checked. FDA's Supplement Facts framework provides for dietary ingredients whose Daily Value is not established. [2]
Human studies use outcome-specific amounts. Standalone trials have used 200 mg/day for four weeks and 200 mg/day of a named ingredient for 28 days, while an acute cognition study used 250 mg alone. [3][4][6] A 2025 sleep review covered 50–900 mg/day and highlighted 200–450 mg/day as promising, but this is not an FDA recommended range. [8]
What the L-theanine evidence shows
Standalone L-theanine has small human trials suggesting possible effects on stress, sleep and selected attention measures, but the evidence base is still modest and short-term. [3][4][10]
Acute cognitive evidence is stronger for some L-theanine + caffeine combinations. A 44-person trial using 97 mg L-theanine with 40 mg caffeine improved selected task-switching and alertness outcomes. [5] Another crossover study showed broader positive effects from the combination than from L-theanine alone. [6]
L-theanine evidence by goal
Evidence by goal
Goal
Evidence strength
What was assessed
Typical study context
Main limitation
Stress-related symptoms
Promising but limited
Standalone L-theanine
Short controlled trials around 200 mg/day for roughly four weeks.
Modest samples, short duration and multiple endpoints.
Heterogeneous; includes open-label studies and limited clinical-insomnia evidence.
Acute focus/attention
Moderate for selected outcomes in caffeine combinations
L-theanine + caffeine
One study used 97 mg L-theanine + 40 mg caffeine in 44 young adults.
Cannot isolate the effect of L-theanine.
Attention without caffeine
Limited
Standalone L-theanine
Small controlled studies report selected attention/working-memory findings.
Population/test-specific; not a broad cognitive-enhancement conclusion.
Read the full evidence-by-goal detail
Stress and calm
Standalone 200 mg/day trials report improvements in selected stress outcomes over about four weeks, but sample sizes and follow-up are limited. [3][4]
Sleep
A 2025 systematic review included 13 standalone trials and 550 participants, with benefits reported across several sleep outcomes. More high-quality work is still needed. [8]
Focus and attention
Some standalone studies report selected attention effects, but multiple acute studies use caffeine combinations. [5][6][7] The caffeine dose must therefore remain visible in comparisons.
When to take L-theanine
No universal timing rule is established. Acute attention trials dose L-theanine before cognitive testing, whereas sleep trials use different schedules and durations. [8] Follow the product label unless a healthcare professional advises otherwise.
For combination products, caffeine timing may matter more for sleep than L-theanine timing, so the caffeine amount should never be hidden inside a blend.
L-theanine safety and interaction context
Who should be cautious?If any of the following apply to you, speak to a healthcare professional before taking L-Theanine - see the full detail below for why.
Pregnant or breastfeeding people because concentrated supplement safety is not well established
People taking prescription medicines
People with medical conditions where sedative, stimulant or blood-pressure effects could be relevant
People sensitive to caffeine when considering L-theanine + caffeine products
FDA does not approve dietary supplements for safety and effectiveness before marketing. [1] Short-term human studies generally report good tolerability, but longer-term evidence is limited and no formal L-theanine UL was identified. [4][8][9]
FDA cautions generally that supplements can interact with medicines. [13] No authoritative universal L-theanine-specific separation interval was identified, so people taking prescription medicines should use clinician/pharmacist advice rather than a generic timing rule.
L-theanine with caffeine and other ingredients
L-theanine is often paired with caffeine, tea extracts, vitamins, minerals and calming herbs. Record each active separately. Studies using L-theanine + caffeine should support that combination only; they do not prove the same effect from caffeine-free L-theanine. [5][7]
Who might consider L-theanine
Adults comparing L-theanine for stress, sleep or attention can use the evidence to identify products that match studied formulations, but current evidence is not strong enough to turn one dose or branded ingredient into a universal recommendation. [8] People using supplements to manage diagnosed anxiety, insomnia or another condition should use clinical care rather than product rankings.
How to compare L-theanine testing evidence
Useful testing should confirm L-theanine identity and potency, contaminants and the actual finished-product composition. If caffeine is present—or the product claims to be caffeine-free—the caffeine content is also relevant to verification.
FDA cGMP rules address identity, purity, quality, strength, composition and contamination controls. [12] A trademarked L-theanine ingredient can improve study traceability, but it is not independent proof that the finished supplement is superior or matches its label.
Testing evidence in this comparison
A testing claim is not the same as a verified report. No public evidence located does not mean a product has not been tested.
Testing review pending0
Recognised certification2
Verified independent evidence1
Manufacturer COA0
Testing claimed17
No public evidence located5
What does l-theanine cost?
Current US comparison set, based on the daily serving shown on each label.
$0.05Lowest daily cost
$0.22Median daily cost
$0.76Highest daily cost
Your questions, answered
Does L-theanine have an FDA Daily Value?
No L-theanine-specific Daily Value was identified. FDA's supplement-labelling guidance provides for dietary ingredients whose Daily Value is not established. [2]
How much L-theanine is usually studied?
There is no single study dose. Standalone adult trials often use around 200 mg, while a 2025 sleep review included 50–900 mg/day. [3][8] These are research amounts, not an FDA recommendation.
Does L-theanine work better with caffeine?
For some acute attention tasks, combination studies are more consistently positive than L-theanine-alone studies. One trial used 97 mg L-theanine with 40 mg caffeine. [5] That does not mean caffeine is appropriate for everyone.
Does L-theanine help sleep?
A recent systematic review found promising effects across several sleep outcomes, but the studies varied and more high-quality work is needed. [8]
Is 200 mg L-theanine a standard dose?
It is a common commercial and research amount, but it is not an FDA-established standard. NOW currently sells a 200 mg capsule product, while studies and other products use different amounts. [11]
