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Dietary supplement

SunTheanine Ingredients & Drug Interactions

by Tomorrow's Nutrition Pro

SunTheanine 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 SunTheanine 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

SunTheanine is a dietary supplement by Tomorrow's Nutrition Pro 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 Suntheanine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against SunTheanine by Tomorrow's Nutrition Pro

Ask about any prescription or over-the-counter medication and we check it for interactions with SunTheanine by Tomorrow's Nutrition Pro — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of SunTheanine by Tomorrow's Nutrition Pro

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.

SunTheanine by Tomorrow's Nutrition Pro is a single-ingredient supplement: theanine (marketed as Suntheanine), an amino acid derived from green tea. The capsule itself contains vegetable cellulose and rice extract as inactive ingredients.

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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: stress relief, sleep quality, and mental focus.
  • We looked for evidence on: Stress, Insomnia, Generalized anxiety disorder (GAD), Cognitive function, Relaxation, Attention.
  • The strongest evidence on file: Theanine is rated "Possibly Effective" for Cognitive function (Natural Medicines).
  • Also on file: Theanine is rated "Insufficient Reliable Evidence To Rate" for Generalized anxiety disorder (GAD), Attention deficit-hyperactivity disorder (ADHD), Insomnia, Stress.

The evidence for theanine is mixed depending on what you're taking it for. It's possibly effective for cognitive function — meaning there's some research backing it, though more work is needed.

For age-related cognitive decline, Alzheimer disease, generalized anxiety disorder, obsessive-compulsive disorder, and cancer, the evidence we have isn't enough to make a reliable call. If you're considering theanine for any of those uses, talk with us about what the research actually shows and whether it makes sense for you.

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.

Theanine is generally well tolerated in healthy adults for short-term use, but how safe it is over the long haul hasn't been well studied. Common side effects include headaches, drowsiness, longer sleep, and more vivid dreams.

The safety data during pregnancy and breastfeeding is insufficient, so it's best to avoid this supplement if you're pregnant or nursing until you've talked with your doctor or pharmacist.

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 taking SunTheanine, double-check if you're on any blood pressure medications (antihypertensives) — theanine can make them work stronger, which could lower your pressure too much. Also flag any sedating medications (CNS depressants) like sleep aids or anxiety drugs, and any antidepressants or serotonergic medications you take, though the serotonin interaction remains unclear.

Check your own medication Run your meds through the checker above

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.

If you're looking for a cognitive boost and you're not on blood pressure medication or sedating drugs, this is worth discussing with your pharmacist. If you take a blood pressure pill, sleep aid, or antidepressant, check your specific medications first — theanine can interact with them.

Pregnant or breastfeeding? Skip it for now and ask us what's safe.

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 Jun 23, 2017.

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 SunTheanine, straight from the product label.

Brand Tomorrow's Nutrition Pro
Barcode (UPC) 850236004170
Net contents 62 Vegetable Capsule(s)
Market status On market
Date entered into DSLD Jun 23, 2017
DSLD ID 74993
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Kosher, 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 SunTheanine by Tomorrow's Nutrition Pro, 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
62
UPC/BARCODE
850236004170
IngredientAmount% DV
Suntheanine200 mg--

Other ingredients: Vegetable Cellulose, Rice extract

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.
Formula

Tomorrow’s Nutrition Pro Suntheanine delivers 200 mg of clinically proven, award-winning and patented L-theanine.

OK

L-Theanine 200

General Statements

Supports stress relief Improves quality of sleep Improves mental focus

BPA free bottle

Improves focus & concentration Reduces stress without drowsiness

Seals/Symbols

OK

Formulation

Gluten free Non-dairy Non-GMO

Vegan

Contains no artificial sweeteners, dairy, wheat or yeast.

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Recommendations: Adults, as a dietary supplement, take once or twice daily.

Precautions

Do not use if safety seal is broken or missing.

Keep out of reach of children.

Warning: If pregnant, nursing, or taking prescription drugs, consult your healthcare practitioner prior to use.

Storage

Store in a cool dry place.

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.

Brand IP Statement(s)

Suntheanine is a trademark of Taiyo International, Inc.

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

See for yourself

SunTheanine by Tomorrow's Nutrition Pro label

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

SunTheanine 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 SunTheanine by Tomorrow's Nutrition Pro

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 container62 Amounts shown are per serving.

Suntheanine

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...

Suntheanine monograph & interactions

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

Interaction report

SunTheanine by Tomorrow's Nutrition Pro Drug Interactions

Want to check YOUR meds against SunTheanine?

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

Suntheanine 565

Individual Drug Interactions

The ingredients in SunTheanine interact with 565 drugs. Click any drug to see the details.

1 of the 1 ingredient in SunTheanine interact with drugs. Each result below shows which ingredient is responsible. Suntheanine

Each ingredient & the kinds of drugs it affects

For each ingredient in SunTheanine 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.

Suntheanine3 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
Suntheanine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for SunTheanine, from the product label.

Tomorrow's Nutrition Pro

See all Tomorrow's Nutrition Pro products
Name
Tomorrow's Nutrition Pro
City
Minneapolis
State
MN
Phone Number
888.380.2322
Pharmacist Counseling Corner

SunTheanine by Tomorrow's Nutrition Pro: Common Questions

Does SunTheanine by Tomorrow's Nutrition Pro interact with any medications?
Yes. Based on its ingredients, SunTheanine 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?
SunTheanine 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.
Can I take this if I'm pregnant or breastfeeding?
There isn't enough safety data to know either way, so the recommendation is to avoid it during pregnancy and while breastfeeding. Talk with your doctor or pharmacist about whether theanine is right for you in either situation.
What are the side effects I should watch for?
The most common ones are headaches, drowsiness, longer sleep, and more vivid dreams. A few people have reported dizziness or other effects, but these are less common. Let us know if any bother you.
Does theanine actually help with anxiety?
The evidence for anxiety disorders like GAD and OCD isn't strong enough yet to make a solid recommendation. If anxiety relief is what you're after, talk with your doctor about proven options.
How long can I safely take this?
Theanine is generally well tolerated in the short term, but we don't have good data on long-term safety. If you want to take it regularly for weeks or months, check in with your pharmacist or doctor first.
What exactly is Suntheanine?
It's theanine, an amino acid found naturally in green tea. This product gives you a concentrated dose in capsule form without the caffeine.

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

Not sure if SunTheanine 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.

SunTheanine label
Go deeper

The Full Monographs Behind SunTheanine’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

SunTheanine'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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