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Dietary supplement

SunTheanine Citrus 100 mg Ingredients & Drug Interactions

by Tomorrow's Nutrition

SunTheanine Citrus 100 mg label
See full label image
Tablet Or Pill Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Oct 7, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking SunTheanine Citrus 100 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

SunTheanine Citrus 100 mg is a dietary supplement by Tomorrow's Nutrition 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 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 SunTheanine Citrus 100 mg by Tomorrow's Nutrition

Ask about any prescription or over-the-counter medication and we check it for interactions with SunTheanine Citrus 100 mg by Tomorrow's Nutrition — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of SunTheanine Citrus 100 mg by Tomorrow's Nutrition

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 Sep 17, 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 Citrus contains one active ingredient: Suntheanine L-theanine at 100 mg per tablet. L-theanine is an amino acid that occurs naturally in tea and is believed to support relaxation and mental clarity.

The tablet also includes inactive ingredients: xylitol (sweetener), natural flavors, vegetable cellulose (capsule material), vegetable powder, citric acid, and stevia leaf extract.

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: improve focus, concentration, and sleep quality.
  • We looked for evidence on: Cognitive function, Insomnia, Stress, Generalized anxiety disorder (GAD), Attention deficit-hyperactivity disorder (ADHD), attention — and 2 related terms.
  • 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 L-theanine is mixed depending on what you're using it for. It's rated possibly effective for supporting cognitive function — meaning there's some promising research, but more study is needed.

For age-related cognitive decline, Alzheimer's disease, generalized anxiety, obsessive-compulsive disorder, and cancer, the evidence we hold is insufficient to rate it one way or the other.

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 well enough to know what happens with extended use. The most common side effects reported are headaches, drowsiness, increased sleep duration, and more vivid dreams.

One child on a much higher dose (400 mg daily) developed facial tics, though they stopped when the supplement was discontinued — and this child had a history of tics, so the connection wasn't clear. There isn't enough safety data in pregnancy or breastfeeding, so the data advises against use during either.

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 this product, check with your doctor or pharmacist if you take blood pressure medications (antihypertensive drugs) — theanine might lower your blood pressure further. Also double-check if you use any sedatives, sleep aids, or other central nervous system depressants.

The serotonin effect is uncertain and no syndrome cases have been reported, but mention it if you're on serotonergic medications (like certain antidepressants).

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.

L-theanine may help with focus and clarity, though the evidence is strongest for cognitive function overall. If you take blood pressure medication or any sedative, talk with your doctor or pharmacist before starting — theanine could affect how those drugs work.

Pregnant or breastfeeding people should avoid it. Check your medications on this page before you begin.

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 Apr 25, 2019.

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 Citrus 100 mg, straight from the product label.

Brand Tomorrow's Nutrition
Barcode (UPC) 850236004040
Net contents 60 Chewable Tablet(s)
Market status On market
Date entered into DSLD Apr 25, 2019
DSLD ID 201443
Product type Non-nutrient/non-botanical
Supplement form Tablet Or Pill
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
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 Citrus 100 mg by Tomorrow's Nutrition, 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 Tablet(s)
Maximum serving Sizes:
1 Tablet(s)
Servings per container
60
UPC/BARCODE
850236004040
IngredientAmount% DV
Suntheanine L-Theanine100 mg--

Other ingredients: Xylitol, Natural flavors, Vegetable Cellulose, Vegetable Powder, Citric Acid, Stevia leaf 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.
Precautions

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

Do not use if safety seal is broken or missing.

Keep out of the reach of children.

Formula

Tomorrow's Nutrition Citrus Chewables deliver 100 mg of clinically proven Suntheanine L-Theanine per delicious chewable tablet.

L-Theanine 100

General Statements

Suntheanine has been shown to improve focus and concentration, reduce stress and improve the quality of sleep.

Improves focus & concentration Reduces stress without drowsiness

Storage

Store in a cool dry place.

General

Rev. 4

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

Recommendations: As a dietary supplement, take one chewable tablet once or twice daily.

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 Citrus 100 mg by Tomorrow's Nutrition label

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

SunTheanine Citrus 100 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 SunTheanine Citrus 100 mg by Tomorrow's Nutrition

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

Serving size1 Tablet(s) Dosage formTablet Or Pill Servings per container60 Amounts shown are per serving.

Suntheanine L-Theanine

Interacts with
565 drugs
100 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 L-Theanine monograph & interactions

Other (inactive) ingredients: Xylitol, Natural flavors, Vegetable Cellulose, Vegetable Powder, Citric Acid, Stevia leaf extract. These complete the product’s ingredient list but are not active constituents.

Interaction report

SunTheanine Citrus 100 mg by Tomorrow's Nutrition Drug Interactions

Want to check YOUR meds against SunTheanine Citrus 100 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

Suntheanine L-Theanine 565

Individual Drug Interactions

The ingredients in SunTheanine Citrus 100 mg interact with 565 drugs. Click any drug to see the details.

1 of the 1 ingredient in SunTheanine Citrus 100 mg interact with drugs. Each result below shows which ingredient is responsible. Suntheanine L-Theanine

Each ingredient & the kinds of drugs it affects

For each ingredient in SunTheanine Citrus 100 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.

Suntheanine 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
Suntheanine L-Theanine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for SunTheanine Citrus 100 mg, from the product label.

Tomorrow's Nutrition

See all Tomorrow's Nutrition products
Name
Tomorrow's Nutrition
City
Minneapolis
State
MN
Phone Number
888-380-2322
Web Address
www.tomorrownutrition.com
Pharmacist Counseling Corner

SunTheanine Citrus 100 mg by Tomorrow's Nutrition: Common Questions

Does SunTheanine Citrus 100 mg by Tomorrow's Nutrition interact with any medications?
Yes. Based on its ingredients, SunTheanine Citrus 100 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?
SunTheanine Citrus 100 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.
Can I take this if I'm pregnant or breastfeeding?
No. There isn't enough safety data for L-theanine in pregnancy or breastfeeding, so the data advises against it. Talk with your doctor or pharmacist about what's safe for you.
What are the side effects?
The most common ones reported are headaches, drowsiness, increased sleep duration, and more vivid dreams. Most people tolerate it well for short-term use, but long-term safety isn't well studied.
Does this actually work for cognitive function?
L-theanine is rated possibly effective for cognitive function — there's some promising research, but more evidence is needed. For other uses like anxiety, Alzheimer's, or OCD, we don't have enough reliable evidence to say either way.
Is this just an amino acid from tea?
Yes. L-theanine occurs naturally in tea leaves and is the active ingredient here. This is a concentrated 100 mg dose in tablet form.
Can I take this with my sleep medication?
You'll need to check with your doctor or pharmacist first. Theanine may add to the drowsy effect of sleep aids and sedatives, and it's unclear how much of a real concern that is for you personally.

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

Not sure if SunTheanine Citrus 100 mg is safe with your meds?

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Ask a pharmacist

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 Citrus 100 mg label
Go deeper

The Full Monographs Behind SunTheanine Citrus 100 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

SunTheanine Citrus 100 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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