L-Theanine Ingredients & Drug Interactions
What is this page for?
First and foremost: checking L-Theanine 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
L-Theanine is a dietary supplement by SmarterVitamins with 2 active ingredients. Its ingredients are commonly taken for source of omega-3 (ala) fatty acids, heart and cholesterol health, dry skin and inflammation.Based on those ingredients, 665 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are L-Theanine, Flaxseed Oil. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against L-Theanine by SmarterVitamins
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Theanine by SmarterVitamins — and tell you which ingredient is responsible.
AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of L-Theanine by SmarterVitamins
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.
What’s inside
Full disclosure
SmarterVitamins L-Theanine is a 2-ingredient softgel with flaxseed oil and L-theanine as the active components. Flaxseed oil is a plant-based omega-3 source, and L-theanine is an amino acid found naturally in tea.
The capsule itself is made from softgel material, beeswax, and sunflower lecithin.
Does it work?
Moderate evidence
The evidence for L-theanine on cognitive function is possibly effective based on the data we hold, though studies on age-related cognitive decline, Alzheimer disease, anxiety disorders, and cancer are insufficient to rate. Flaxseed oil shows possibly ineffective ratings for obesity, rheumatoid arthritis, bipolar disorder, and high cholesterol (hyperlipidemia) — meaning the evidence does not support its use for these purposes.
How safe is it?
Well-documented data
L-theanine is generally well tolerated in healthy adults for short-term use, but long-term safety hasn't been well studied. The safety data advises against its use during pregnancy and breastfeeding because there isn't enough information to know it's safe.
Flaxseed oil is generally well tolerated, though a small number of people report changes in bowel habits, dry mouth, or upset stomach at typical doses; higher doses can cause loose stools or diarrhea. Rare severe allergic reactions are possible.
The safety data for flaxseed oil in pregnancy is rated possibly safe, but there's limited information during breastfeeding, so medical advice is recommended.
Meds to double-check
Moderate interaction found
Before taking this product, double-check with your doctor or pharmacist if you take blood thinners or antiplatelet drugs (moderate risk of increased bleeding), blood pressure medications (moderate risk of low blood pressure), ezetimibe/Zetia (blocks absorption of the flaxseed oil component), sedating drugs like sleep aids (minor risk of added drowsiness), or serotonergic medications like antidepressants (minor theoretical interaction, though no cases have been reported).
The bottom line
Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.
This product combines flaxseed oil and L-theanine, two ingredients with limited proven effectiveness for their common uses. The bigger question is whether it interacts with your blood pressure medication, blood thinners, cholesterol drugs, or sedating medications — or antidepressants.
Talk with your doctor or pharmacist about your exact medications before starting this supplement.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Feb 25, 2021.
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
General information
Key facts about L-Theanine, straight from the product label.
| Brand | SmarterVitamins |
|---|---|
| Barcode (UPC) | X001YTAMAZ |
| Net contents | 50 Softgel(s) |
| Market status | On market |
| Date entered into DSLD | Feb 25, 2021 |
| DSLD ID | 243859 |
| Product type | Other Combinations |
| Supplement form | Softgel Capsule |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years), Dairy Free, Sugar Free |
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 by SmarterVitamins, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Flaxseed Oil | 300 mg | -- |
| L-Theanine | 250 mg | -- |
Other ingredients: Softgel Capsule, Beeswax, Sunflower Lecithin
Tap any ingredient to jump to its full detail below.
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.
General Statements
Cleaner. Better. Smarter.
Formula
L-theanine is an amino acid that promotes an alert state of relaxation, and enhances mental clarity & focus. Flaxseed oil provides ALA omega-3 essential fatty acid for an extra source of energy & brain support. L-theanine is derived from green tea which helps moderate occasional stress + anxiety.
Made with flaxseed oil
Formulation
Alertness + Calmness
No BS (Bad Stuff): Corn oil, eggs, milk, wheat, peanut, maltodextrin, soy, lactose, carrageenan, magnesium stearate, dioxides, fillers, sugar, starch, soy bean oil, palm oil, talc or preservatives.
Storage
Store in a cool, dry place away from heat and light.
FDA Disclaimer Statement
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
FDA Statement of Identity
Dietary Supplement
Suggested/Recommended/Usage/Directions
Suggested Use: As a dietary supplement, take 1 softgel 1 to 2 times daily as needed, preferably on an empty stomach.
Precautions
Caution: As with any dietary supplement, consult your healthcare practitioner before using this or any other product if you are pregnant, nursing, trying to conceive, taking medication or have a medical condition.
Keep out of reach of children.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Theanine by SmarterVitamins label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
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)The Ingredients in L-Theanine by SmarterVitamins
These are the 2 active ingredients this product is made of. Select any to open its full monograph.
Serving size1 Softgel(s) Dosage formSoftgel Capsule Servings per container50 Amounts shown are per serving.
Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.
Flaxseed Oil
Interacts with293 drugs
Flaxseed oil is a plant-based source of the omega-3 fatty acid ALA, which the body can partly convert to the omega-3s found in fish oil. It may help s...
Flaxseed Oil monograph & interactionsL-Theanine
Interacts with565 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 dro...
L-Theanine monograph & interactionsOther (inactive) ingredients: Softgel Capsule, Beeswax, Sunflower Lecithin. These complete the product’s ingredient list but are not active constituents.
L-Theanine by SmarterVitamins Drug Interactions
HelloPharmacist Interaction Report
L-Theanine by SmarterVitamins has documented interactions with medications through both its flaxseed oil and L-theanine content.
The most serious concern is moderate-severity: flaxseed oil may increase bleeding risk when combined with blood thinners and antiplatelet drugs (drugs that prevent clots). Both ingredients can also lower blood pressure, and combining them with blood pressure medications may cause blood pressure to drop too far.
Read the full breakdown — every affected drug type, severity by severity
Flaxseed oil also interacts with ezetimibe (Zetia), a cholesterol medication — taking them together blocks how well your body absorbs the active part of flaxseed oil. L-Theanine carries a minor interaction with sedating drugs (CNS depressants like sleep aids or anxiety medications), as it may add to drowsiness, though it's unclear how much this matters in practice.
It also has a minor, theoretical interaction with serotonergic drugs (antidepressants and similar medications), though no cases of serotonin syndrome have been reported.
Altogether, these interactions span 665 individual medications.
Use the medication checker below to search your exact prescriptions before starting this product.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against L-Theanine?
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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in L-Theanine interact with 665 drugs. Click any drug to see the details.
2 of the 2 ingredients in L-Theanine interact with drugs. Each result below shows which ingredient is responsible. L-Theanine Flaxseed Oil
AbciximabReoPro
How Abciximab interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Abciximab interactionAbrocitinibCibinqo
How Abrocitinib interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Abrocitinib interactionAcebutololRhotral, Sectral
How Acebutolol interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Acebutolol interactionL-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Acebutolol interactionAcenocoumarolSintrom
How Acenocoumarol interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Acenocoumarol interactionAcetaminophen, AspirinGemnisyn
How Acetaminophen, Aspirin interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Acetaminophen, Aspirin interactionAcetaminophen, Aspirin, CaffeineExcedrin, Excedrin Extra Strength, Excedrin Migraine
How Acetaminophen, Aspirin, Caffeine interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Acetaminophen, Aspirin, Caffeine interactionAcetaminophen, IbuprofenCombogesic
How Acetaminophen, Ibuprofen interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Acetaminophen, Ibuprofen interactionAcetazolamideAk-Zol, Diamox
How Acetazolamide interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
L-theanineCns Depressants, Antihypertensive Drugs Moderate
Interaction Summary
Theoretically, theanine might have additive sedative effects when used in conjunction with CNS depressants.
Read the full L-theanine + Acetazolamide interactionFlaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Acetazolamide interactionAcetylsalicylic AcidEntrophen
How Acetylsalicylic Acid interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Acetylsalicylic Acid interactionAliskirenTekturna
How Aliskiren interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
L-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Aliskiren interactionFlaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Aliskiren interactionAlteplase, TpaActilyse, Activase
How Alteplase, Tpa interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Alteplase, Tpa interactionAluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium HydroxideAscriptin Codeine #2
How Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interactionL-theanineCns Depressants Minor
Interaction Summary
Theoretically, theanine might have additive sedative effects when used in conjunction with CNS depressants.
Read the full L-theanine + Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interactionAluminum Hydroxide, Aspirin, Magnesium HydroxideAscriptin
How Aluminum Hydroxide, Aspirin, Magnesium Hydroxide interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Aluminum Hydroxide, Aspirin, Magnesium Hydroxide interactionAmbrisentanLetairis, Volibris
How Ambrisentan interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Ambrisentan interactionL-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Ambrisentan interactionAmilorideAmilamont, Midamor
How Amiloride interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Amiloride interactionL-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Amiloride interactionAmiloride, HydrochlorothiazideAmil-Co, Amilzide, Moduret 25, Moduretic
How Amiloride, Hydrochlorothiazide interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
L-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Amiloride, Hydrochlorothiazide interactionFlaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Amiloride, Hydrochlorothiazide interactionAmlodipineNorliqva
How Amlodipine interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
L-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Amlodipine interactionFlaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Amlodipine interactionAmlodipine BenzoateKaterzia
How Amlodipine Benzoate interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Amlodipine Benzoate interactionL-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Amlodipine Benzoate interactionAmlodipine BesilateIstin
How Amlodipine Besilate interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
L-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Amlodipine Besilate interactionFlaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Amlodipine Besilate interactionAmlodipine BesylateNorvasc
How Amlodipine Besylate interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Amlodipine Besylate interactionL-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Amlodipine Besylate interactionAmlodipine Besylate, BenazeprilLotrel
How Amlodipine Besylate, Benazepril interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
L-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Amlodipine Besylate, Benazepril interactionFlaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Amlodipine Besylate, Benazepril interactionAmlodipine, CelecoxibConsensi
How Amlodipine, Celecoxib interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Amlodipine, Celecoxib interactionL-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Amlodipine, Celecoxib interactionAmmonium ChlorideAmmonium Chloride
How Ammonium Chloride interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
L-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Ammonium Chloride interactionFlaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Ammonium Chloride interactionAnacaulase-bcdbNexoBrid
How Anacaulase-bcdb interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Anacaulase-bcdb interactionAnagrelideAgrylin
How Anagrelide interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Anagrelide interactionAnisindioneMiradon
How Anisindione interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Anisindione interactionAntithrombin IiiThrombate III
How Antithrombin Iii interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Antithrombin Iii interactionApixabanEliquis
How Apixaban interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Apixaban interactionAprocitentanTryvio
How Aprocitentan interacts with L-Theanine — through 2 ingredients. Tap an ingredient for the detail:
Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Flaxseed Oil + Aprocitentan interactionL-theanineAntihypertensive Drugs Moderate
Interaction Summary
Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Read the full L-theanine + Aprocitentan interactionArgatrobanArgatroban
How Argatroban interacts with L-Theanine — through 1 ingredient. Tap an ingredient for the detail:
Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Flaxseed Oil + Argatroban interactionEach ingredient & the kinds of drugs it affects
For each ingredient in L-Theanine with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.
L-Theanine
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.
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.
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.
Flaxseed Oil
Anticoagulant/Antiplatelet Drugs
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Small clinical studies show that consuming flaxseed oil might decrease platelet aggregation and increase bleeding time.
Antihypertensive Drugs
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Some clinical evidence suggests that long-term consumption of flaxseed oil can modestly lower systolic and diastolic blood pressure, while other clinical research shows no effect.
Ezetimibe (Zetia)
Concomitant use of flaxseed oil and ezetimibe reduces the absorption of alpha-linolenic acid from flaxseed oil.
In one clinical study, concomitant consumption of ezetimibe 10 mg daily with flaxseed oil 2 grams providing 1 gram of alpha-linolenic acid daily blocked the absorption of alpha-linolenic acid, resulting in an overall reduction in alpha-linolenic plasma levels from baseline.
Brand information
Manufacturer and brand details for L-Theanine, from the product label.
SmarterVitamins
See all SmarterVitamins products- Name
- SmarterVitamins Corp.
- City
- Miami
- State
- FL
- ZipCode
- 33131
- Phone Number
- 888.355.2399
- Web Address
- smartervitamins.com
L-Theanine by SmarterVitamins: Common Questions
Does L-Theanine by SmarterVitamins interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Will L-Theanine help me focus or improve my memory?
Is flaxseed oil in this product good for my cholesterol?
Can I take this while pregnant or breastfeeding?
What side effects might L-theanine cause?
Does flaxseed oil cause digestive issues?
Does this product interact with my antidepressant?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Theanine is safe with your meds?
Our pharmacists answer your medication & supplement questions — free.
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.
The Full Monographs Behind L-Theanine’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Flaxseed Oil
Interacts with 293 drugsFlaxseed oil is a plant-based source of the omega-3 fatty acid ALA, which the body can partly convert to the omega-3s found in fish oil. It may help support heart health and provide healthy...
Read the full Flaxseed Oil monograph → Herb & supplement monographTheanine
Interacts with 565 drugsTheanine (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 & How We Checked
L-Theanine'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.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
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 27 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.
Flaxseed Oil 21 references
- Kolonel LN, Nomura AM, Cooney RV. Dietary fat and prostate cancer: current status. J Natl Cancer Inst 1999;91:414-28. PubMed
- Ramon JM, Bou R, Romea S, et al. Dietary fat intake and prostate cancer risk: a case-control study in Spain. Cancer Causes Control 2000;11:679-85. PubMed
- Nordstrom DC, Honkanen VE, Nasu Y, et al. Alpha-linolenic acid in the treatment of rheumatoid arthritis. A double-blind, placebo-controlled and randomized study: flaxseed vs. safflower seed. Rheumatol Int 1995;14:231-4. PubMed
- De Stefani E, Deneo-Pellegrini H, Boffetta P, et al. Alpha-linolenic acid and risk of prostate cancer: a case-control study in Uruguay. Cancer Epidemiol Biomarkers Prev 2000;9:335-8.
- Giovannucci E, Rimm EB, Colditz GA, et al. A prospective study of dietary fat and risk of prostate cancer. J Natl Cancer Inst 1993;85:1571-9. PubMed
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