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Dietary supplement

L Theanine 200 mg Ingredients & Drug Interactions

by Advance Physician Formulas

L Theanine 200 mg label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking L Theanine 200 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

L Theanine 200 mg is a dietary supplement by Advance Physician Formulas 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.

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Check Your Meds Against L Theanine 200 mg by Advance Physician Formulas

Ask about any prescription or over-the-counter medication and we check it for interactions with L Theanine 200 mg by Advance Physician Formulas — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of L Theanine 200 mg by Advance Physician Formulas

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

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

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 found naturally in tea that works on brain chemistry — specifically, it may influence neurotransmitters like GABA and glutamate that calm the nervous system.

The capsule itself is filled out with rice flour and modified cellulose, which are inert fillers.

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 has possibly effective evidence for supporting cognitive function — that's the strongest rating we have for it. For age-related cognitive decline, Alzheimer disease, generalized anxiety disorder, OCD, and cancer, the evidence we hold isn't established enough to rate it.

If you're considering this for one of those other uses, the science just isn't there yet to say whether it'll help.

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 studied thoroughly. The most commonly reported side effect is headache; some people also experience drowsiness, longer sleep duration, or more vivid dreams.

One pediatric case of facial tics was reported, but it occurred in a child with a history of tics and stopped when the supplement was discontinued, so it wasn't clearly caused by theanine. There isn't enough safety data to use this during pregnancy or while breastfeeding — talk with your doctor or pharmacist if you're in either situation to decide what's best for you.

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.

Check with your pharmacist if you take blood pressure medications (antihypertensives) — theanine can lower blood pressure and may potentiate their effect. If you take sedating medications or CNS depressants (like sleep aids), there's a minor theoretical risk of extra drowsiness.

Serotonergic drugs (like certain antidepressants) have conflicting evidence and no documented cases of problems, so the risk appears low — but mention them anyway when you check.

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 everyday cognitive sharpness if the evidence holds up for you. It's most important to check it against any blood pressure medication you take, since it can add to that effect.

If you're generally healthy and not on medications that interact with it, it's usually well tolerated short-term — but long-term use hasn't been well studied. Run your exact medication list through our interaction checker before you start.

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 Sep 25, 2025.

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 200 mg, straight from the product label.

Brand Advance Physician Formulas
Barcode (UPC) 896996000403
Net contents 60 Vegetable Capsule(s)
Market status On market
Date entered into DSLD Sep 25, 2025
DSLD ID 337938
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses Nutrient, All Other
Intended target group(s) Adult (18 - 50 Years), No Allergies, Gluten Free, Dairy Free
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 200 mg by Advance Physician Formulas, 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
60
UPC/BARCODE
896996000403
IngredientAmount% DV
L-Theanine200 mg--

Other ingredients: Rice Flour, Cellulose, Modified

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.
Formulation

L-Theanine is a naturally occurring amino acid found in several types of tea including black, oolong, and green tea.

This product is not manufactured with milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soy, sesame, or gluten.

Vcaps Plus

Precautions

Warnings: For adults only. Keep out of reach of children.

Consult with a qualified healthcare professional prior to taking this product especially if you are pregnant, nursing, have a diagnosed medical condition, or are taking a prescription medication.

Sealed for your protection. Do not use if seal is missing or broken.

This product is not manufactured with milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soy, sesame, or gluten. Produced in an FDA-registered, third-party audited, and cGMP-compliant facility that may process other products that contain these allergens or ingredients.

Storage

Store at room temperature, in a dry place. Protect product from excessive heat, freezing, humidity, and light.

Brand IP Statement(s)

Vcaps is a trademark of Lonza or its affiliates.

Formula

L-Theanine 200 mg per serving

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, healthy adults take one capsule daily in the morning with or without food or as recommended by a qualified healthcare professional.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

L Theanine 200 mg by Advance Physician Formulas label

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

L Theanine 200 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in L Theanine 200 mg by Advance Physician Formulas

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 container60 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: Rice Flour, Cellulose, Modified. These complete the product’s ingredient list but are not active constituents.

Interaction report

L Theanine 200 mg by Advance Physician Formulas Drug Interactions

Want to check YOUR meds against L Theanine 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

L-Theanine 565

Individual Drug Interactions

The ingredients in L Theanine 200 mg interact with 565 drugs. Click any drug to see the details.

1 of the 1 ingredient in L Theanine 200 mg interact with drugs. Each result below shows which ingredient is responsible. L-Theanine

Each ingredient & the kinds of drugs it affects

For each ingredient in L Theanine 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
L-Theanine full monograph & interactions
The maker

Brand information

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

Advance Physician Formulas

See all Advance Physician Formulas products
Name
Advance Physician Formulas Inc.
Street Address
17165 Von Karman Avenue, Suite 109
City
Irvine
State
California
ZipCode
92614
Web Address
physicianformulas.com
Pharmacist Counseling Corner

L Theanine 200 mg by Advance Physician Formulas: Common Questions

Does L Theanine 200 mg by Advance Physician Formulas interact with any medications?
Yes. Based on its ingredients, L Theanine 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 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 influences brain chemistry, particularly GABA and glutamate, neurotransmitters involved in calming. We have the strongest evidence for its use in supporting cognitive function. For anxiety, sleep, and age-related decline, the evidence we hold isn't solid enough to rate.
Can I take this while I'm pregnant or breastfeeding?
There isn't enough safety data on L-theanine in pregnancy or breastfeeding. Talk with your doctor or pharmacist to weigh the pros and cons for your situation — they know your full picture.
What side effects might I notice?
Headache is the most common report. Some people also notice drowsiness, sleeping longer, or more vivid dreams. These are usually mild, but let us know if they're bothersome or don't ease.
How long can I safely take this?
L-theanine is generally well tolerated in healthy adults for short-term use. Long-term safety hasn't been well studied, so if you're thinking of taking it long-term, it's a good idea to check in with your pharmacist or doctor about whether that makes sense for you.
Does this product have any fillers or inactive ingredients?
Yes — it contains rice flour and modified cellulose as inactive ingredients that make up the capsule. These are standard fillers and don't affect how the active L-theanine works.

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

Not sure if L Theanine 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 200 mg label
Go deeper

The Full Monographs Behind L Theanine 200 mg’s Ingredients

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

Herb & supplement monograph

Theanine

Interacts with 565 drugs

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 drowsiness. Early research suggests it may...

Read the full Theanine monograph →
Sources

Sources & How We Checked

L Theanine 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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