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Dietary supplement

L-Theanine Capsules 200 mg Ingredients & Drug Interactions

by Nootropics Depot

Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

L-Theanine Capsules 200 mg is a dietary supplement by Nootropics Depot with 1 active ingredient. Its ingredients are commonly taken for anxiety and stress, relaxation and calm, sleep support.Based on those ingredients, 565 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are L-Theanine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of L-Theanine Capsules 200 mg by Nootropics Depot

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: L-theanine at 200 mg per capsule. L-theanine is an amino acid that works on the nervous system.

The remaining ingredients — microcrystalline cellulose, magnesium stearate, and vegetable cellulose — are inactive fillers and binders that make up the capsule.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed

This product doesn't appear to be marketed for a specific use, so we graded Theanine's overall clinical evidence instead.

Moderate

Some clinical evidence supports Theanine for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Cognitive function — rated "Possibly Effective" (Natural Medicines).

L-theanine is possibly effective for supporting cognitive function according to the evidence we hold. For age-related cognitive decline, Alzheimer disease, generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), and cancer, the evidence isn't established — there's insufficient reliable data to rate it either way.

If you're considering this supplement for a specific health concern, talk with your doctor or pharmacist about whether the evidence supports its use for your situation.

The evidence, ingredient by ingredient Theanine

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

L-theanine is generally well tolerated in healthy adults for short-term use, but long-term safety hasn't been well studied. Reported side effects include headaches, drowsiness, increased sleep duration, and increased dream activity.

One pediatric case reported a facial tic starting within days of taking 400 mg daily, though the tic stopped when the supplement was stopped and wasn't thought to be related since the child had a history of tics. There isn't enough safety data in pregnancy or while breastfeeding — the evidence advises against use during these times.

Talk with your doctor or pharmacist about whether this product is right for you, especially if you're pregnant, planning to become pregnant, or breastfeeding.

Side effects, ingredient by ingredient Theanine

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Theanine.
  • The most serious interaction on file is rated Moderate.
  • For scale: 565 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before you start L-Theanine Capsules, check with your doctor or pharmacist if you take blood pressure medications — theanine may lower your blood pressure further (Moderate concern). Also double-check if you use sedating drugs like sleep aids or anti-anxiety medications, or serotonergic antidepressants, though the risks are Minor and unconfirmed.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

L-theanine may help with cognitive function, but evidence for other uses is limited. If you take blood pressure medication or sedating drugs, check with your doctor or pharmacist before starting this — theanine could affect how those drugs work.

Short-term use is generally well tolerated, but talk with your healthcare provider to make sure it fits your situation.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Feb 21, 2023.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about L-Theanine Capsules 200 mg, straight from the product label.

Brand Nootropics Depot
Net contents 180 Capsule(s)
Market status On market
Date entered into DSLD Feb 21, 2023
DSLD ID 285820
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for L-Theanine Capsules 200 mg by Nootropics Depot, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
180
IngredientAmount% DV
L-Theanine200 mg--

Other ingredients: Microcrystalline Cellulose, Magnesium Stearate, Vegetable Cellulose

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
FDA Statement of Identity

Dietary Supplement

Precautions

Disclaimer: Always consult with a qualified health physician before taking any new dietary supplement.

Warning: Keep out of reach of children. Do not take this or any other supplement if under the age of 18, pregnant or nursing a baby, or if you have any known or suspected medical conditions, and/or taking prescription drug(s) or OTC medication(s).

Do not take this or any other supplement if under the age of 18, pregnant or nursing a baby, or if you have any known or suspected medical conditions, and/or taking prescription drug(s) or OTC medication(s).

FDA Disclaimer Statement

This product is not intended to diagnose, treat, cure or prevent any diseases. These statements have not been evaluated by the Food & Drug Administration.

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take 1 capsule daily.

Storage

Storage: Store in a cool and dry place. Keep away from direct sunlight and heat.

See for yourself

L-Theanine Capsules 200 mg by Nootropics Depot label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

What’s inside

The Ingredients in L-Theanine Capsules 200 mg by Nootropics Depot

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container180 Amounts shown are per serving.

L-Theanine

Interacts with
565 drugs
200 mg per serving

Theanine (usually L-theanine) is an amino acid found naturally in tea leaves that many people take to feel calmer and less stressed without strong dro...

L-Theanine monograph & interactions

Other (inactive) ingredients: Microcrystalline Cellulose, Magnesium Stearate, Vegetable Cellulose. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Theanine Capsules 200 mg by Nootropics Depot Drug Interactions

Want to check YOUR meds against L-Theanine Capsules 200 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

Go to the checker
565Drugs
172 Moderate 393 Minor

Ingredients driving the most interactions

Each ingredient & the kinds of drugs it affects

For each ingredient in L-Theanine Capsules 200 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

L-Theanine3 drug types · 565 drugs

Antihypertensive Drugs

Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Animal research shows that theanine can lower blood pressure in spontaneously hypertensive animals. Theoretically, concomitant use of theanine and antihypertensive drugs might potentiate the antihypertensive activity.

Likelihood Possible Evidence D
Cns Depressants

Theoretically, theanine might have additive sedative effects when used in conjunction with CNS depressants. However, it is unclear if this concern is clinically relevant.
Theoretically, theanine may compete with glutamate and/or increase plasma gamma-aminobutyric acid (GABA) levels, which could cause CNS depression. In one clinical study, some subjects taking oral theanine reported drowsiness.

Likelihood Unlikely Evidence D
Serotonergic Drugs

Clinical studies regarding the effects of L-theanine on serotonin levels are conflicting. Some studies suggest it can increase serotonin levels in the brain while others report that it may decrease them. Nevertheless, there have been no reports of l-theanine being a causative agent in serotonergic-related side effects or serotonin syndrome.

Likelihood Unlikely Evidence C
The maker

Brand information

Manufacturer and brand details for L-Theanine Capsules 200 mg, from the product label.

Nootropics Depot

See all Nootropics Depot products
Name
Nootropics Depot
Street Address
8380 S. Kyrene Rd. Ste. 110
City
Tempe
State
AZ
ZipCode
85284
Web Address
nootropicsdepot.com
Pharmacist Counseling Corner

L-Theanine Capsules 200 mg by Nootropics Depot: Common Questions

Does L-Theanine Capsules 200 mg by Nootropics Depot interact with any medications?
Yes. Based on its ingredients, L-Theanine Capsules 200 mg has a known interaction with 565 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
L-Theanine Capsules 200 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
What does L-theanine actually do?
L-theanine is an amino acid that affects your nervous system. It's possibly effective for cognitive function according to the research we have, but we don't have solid evidence yet for anxiety, cognitive decline with age, or other uses.
Can I take this while pregnant or breastfeeding?
No — there isn't enough safety data. The evidence advises against using L-theanine supplements during pregnancy or while breastfeeding. Talk with your doctor or pharmacist about what's safe for you in these situations.
What side effects might I notice?
Headaches, drowsiness, longer sleep, and more vivid dreams are the ones most commonly reported. These tend to happen with oral use of the supplement.
Is this safe to take long-term?
We don't have good long-term safety data — it's generally well tolerated for short-term use in healthy adults, but we just don't know as much about extended use. Talk with your pharmacist if you're thinking about taking it regularly.
Why does it interact with so many medications?
The interaction count (565 medications) doesn't mean theanine affects all of them equally or seriously. It adds up because many individual drugs fall into the categories it can interact with — like all the different blood pressure medications or all the different sedating drugs. The interaction_report and med_watch above tell you which types actually matter for this product.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if L-Theanine Capsules 200 mg is safe with your meds?

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

L-Theanine Capsules 200 mg label
Go deeper

The Full Monographs Behind L-Theanine Capsules 200 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Sources

Sources & How We Checked

L-Theanine Capsules 200 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 6 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Theanine 6 references
  1. Yokogoshi H, Kobayashi M. Hypotensive effect of gamma-glutamylethylamide in spontaneously hypertensive rats. Life Sci 1998;62:1065-8.
  2. Haskell, C. F., Kennedy, D. O., Milne, A. L., Wesnes, K. A., and Scholey, A. B. The effects of L-theanine, caffeine and their combination on cognition and mood. Biol.Psychol. 2008;77(2):113-122. PubMed
  3. Yokogoshi, H., Kato, Y., Sagesaka, Y. M., Takihara-Matsuura, T., Kakuda, T., and Takeuchi, N. Reduction effect of theanine on blood pressure and brain 5-hydroxyindoles in spontaneously hypertensive rats. Biosci.Biotechnol.Biochem. 1995;59(4):615-618. PubMed
  4. Lyon MR, Kapoor MP, Juneja LR. The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial. Altern Med Rev. 2011;16(4):348-
  5. Hidese S, Ota M, Wakabayashi C, et al. Effects of chronic l-theanine administration in patients with major depressive disorder: an open-label study. Acta Neuropsychiatr 2017;29(2):72-9.
  6. Tsuchiya T, Honda H, Oikawa M, et al. Oral administration of the amino acids cystine and theanine attenuates the adverse events of S-1 adjuvant chemotherapy in gastrointestinal cancer patients. Int J Clin Oncol 2016;21(6):1085-90. PubMed

See these in context on the Theanine monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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