Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

L-Theanine Complex Ingredients & Drug Interactions

by Solgar

L-Theanine Complex label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 23, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking L-Theanine Complex 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 Complex is a dietary supplement by Solgar with 3 active ingredients. Its ingredients are commonly taken for anxiety and stress, sleep problems, relaxation.Based on those ingredients, 1,073 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Valerian root powdered extract, L-Theanine, GABA. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against L-Theanine Complex by Solgar

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

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HelloPharmacist Scorecard of L-Theanine Complex by Solgar

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 Aug 13, 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 3 of its 3 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains three active ingredients in a capsule form. GABA (gamma-aminobutyric acid) is a neurotransmitter your brain produces naturally to promote relaxation.

L-theanine is an amino acid found in tea that research suggests may support focus and calm. Valerian root powdered extract comes from the valerian plant and has been used traditionally to support sleep.

The remaining ingredients—vegetable cellulose, microcrystalline cellulose, vegetable magnesium stearate, and silica—are inactive fillers and capsule materials.

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: Relaxation, stress relief, and sleep support.
  • We looked for evidence on: Anxiety, Generalized anxiety disorder (GAD), Insomnia, Post-traumatic stress disorder (PTSD), Pre-procedural anxiety, Stress — and 3 related terms.
  • The strongest evidence on file: Valerian is rated "Possibly Effective" for Insomnia (Natural Medicines).
  • Also on file: Gamma-aminobutyric Acid (gaba) is rated "Insufficient Reliable Evidence To Rate" for Anxiety, Insomnia, Post-traumatic stress disorder (PTSD).
  • Also on file: Valerian is rated "Insufficient Reliable Evidence To Rate" for Pre-procedural anxiety, Stress.

The evidence for what this product can do is limited. L-theanine shows possibly effective evidence for supporting cognitive function, though research on age-related cognitive decline and Alzheimer's disease is insufficient.

Valerian root is possibly effective for insomnia, but evidence for restless legs syndrome, pre-procedural anxiety, stress, and menstrual cramps is insufficient. For GABA, the data we have does not establish effectiveness for chronic bronchitis, anxiety, athletic performance, ADHD, or cerebral palsy—all are rated insufficient.

Long-term benefit and safety across all three ingredients remain under-studied.

The evidence, ingredient by ingredient Gamma-aminobutyric Acid (gaba) Theanine Valerian

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 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Orally, GABA and L-theanine are generally well tolerated short-term, but long-term safety is not well studied. Common side effects of GABA include drowsiness, stomach upset, mild throat burning, muscle weakness, and nausea.

L-theanine may cause headaches, drowsiness, longer sleep, and increased dream activity. Valerian root is generally well tolerated but commonly causes dizziness, drowsiness, mental slowness, headache, stomach upset, and vivid dreams.

With chronic valerian use and sudden stopping, withdrawal symptoms such as rapid heartbeat, anxiety, irritability, and insomnia can occur—taper slowly after extended use. Rare serious side effects have been reported with valerian, including cases of liver injury, particularly in multi-ingredient products.

Pregnancy and breastfeeding safety data are not established for all three ingredients; avoid use unless your doctor advises otherwise.

Side effects, ingredient by ingredient Gamma-aminobutyric Acid (gaba) Theanine Valerian

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?
  • 3 of the 3 matched ingredients can interact with medications — Gamma-aminobutyric Acid (gaba), Valerian, Theanine.
  • The most serious interaction on file is rated Moderate.
  • For scale: 1,074 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, double-check with your doctor or pharmacist if you take blood pressure medication (antihypertensive drugs)—both GABA and L-theanine may lower blood pressure further. Also confirm any CNS depressants (sleep aids, anxiety medications, opioids, sedating antihistamines)—valerian carries a Moderate risk of added sedation, as do GABA and L-theanine theoretically.

If you're on alprazolam (Xanax), valerian raises concern for additive sedation and possible increased drug levels. Do not combine with alcohol.

Finally, if you take serotonergic drugs (antidepressants, certain migraine or pain medications), L-theanine's serotonin effects are unclear—check with your pharmacist. If you take medications metabolized by glucuronidation or the CYP3A4 or CYP2D6 enzymes, valerian may affect their levels.

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.

This combination may help with sleep and relaxation in the short term, though evidence is strongest for valerian's use in insomnia and L-theanine for focus. Because all three ingredients can lower blood pressure and cause drowsiness, and valerian has multiple medication interactions, this product isn't right for everyone—especially if you take blood pressure medication, sleep aids, anxiety drugs, or CNS depressants.

Talk with your doctor or pharmacist before starting it, particularly if you take any prescription medications or have liver concerns.

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

Assessment coverage: 3 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Feb 26, 2020.

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 Complex, straight from the product label.

Brand Solgar
Barcode (UPC) 033984027053
Net contents 60 Vegetable Capsule(s)
Market status On market
Date entered into DSLD Feb 26, 2020
DSLD ID 214982
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Vegetarian, Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar 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 Complex by Solgar, 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 Vegetarian Capsule(s)
Maximum serving Sizes:
1 Vegetarian Capsule(s)
UPC/BARCODE
033984027053
IngredientAmount% DV
GABA100 mg--
L-Theanine120 mg--
Valerian root powdered extract100 mg--

Other ingredients: Vegetable Cellulose, Microcrystalline Cellulose, Vegetable Magnesium Stearate, Silica

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

Solgar's L-Theanine Complex Vegetable Capsules are free of yeast, wheat, soy, gluten and dairy products and are formulated without the use of artificial preservatives, flavors or colors.

Suitable for vegetarians

Sugar, salt and starch free

Storage

To assure freshness and potency, store at room temperature 59 degrees-86 degrees F (15 degrees-30 degrees C). Store away from heat, light and moisture.

Precautions

Do not use if outer bottle seal is missing, torn or damaged in any way.

If you are pregnant, nursing, taking any medication or have a medical condition, please consult your healthcare practitioner before taking any dietary supplement.

Keep out of reach of children.

General Statements

Solgar since 1947

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement for adults, take one (1) vegetable capsule two times daily, preferably at mealtimes, or as directed by a healthcare practitioner.

Brand IP Statement(s)

Suntheanine is a registered trademark of Taiyo International, Inc. Use of Suntheanine is protected by U.S. Trademark Reg. No. 2548957.

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

See for yourself

L-Theanine Complex by Solgar label

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

L-Theanine Complex 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 Complex by Solgar

These are the 3 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Vegetarian Capsule(s) Dosage formCapsule 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.

GABA

Interacts with
419 drugs
100 mg per serving

GABA is a calming chemical messenger (neurotransmitter) that your body makes on its own, and it is sold as a supplement for stress, anxiety, and sleep...

GABA monograph & interactions

L-Theanine

Interacts with
565 drugs
120 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

Valerian root powdered extract

Interacts with
902 drugs
100 mg per serving

Valerian is an herb whose root is widely used as a natural sleep aid and for calming nerves. The evidence is mixed and often weak, so it may help some...

Valerian root powdered extract monograph & interactions

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

Interaction report

L-Theanine Complex by Solgar Drug Interactions

Want to check YOUR meds against L-Theanine Complex?

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
1,073Drugs
509 Moderate 564 Minor

Ingredients driving the most interactions

Valerian root powdered extract 902
L-Theanine 565
GABA 419

Individual Drug Interactions

The ingredients in L-Theanine Complex interact with 1,073 drugs. Click any drug to see the details.

3 of the 3 ingredients in L-Theanine Complex interact with drugs. Each result below shows which ingredient is responsible. Valerian root powdered extract L-Theanine GABA

Each ingredient & the kinds of drugs it affects

For each ingredient in L-Theanine Complex 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.

Valerian root powdered extract6 drug types · 902 drugs

Alcohol (Ethanol)

Valerian can have additive sedative effects when used concomitantly with alcohol.
Valerian has sedative effects. Theoretically, valerian might have an additive sedative effect when combined with alcohol. Excessive sedation has been reported in an alcohol-abusing individual who took valerian and Gingko biloba. However, the potential interaction between valerian and alcohol has been disputed in other research. Limited evidence suggests that a combination of valerian 160 mg and lemon balm 80 mg (Euvegal) does not cause further deterioration in reaction ability and reaction rate when taken with alcohol as compared to the effects of alcohol alone.

Likelihood Possible Evidence B
Alprazolam (Xanax)

Valerian can have additive sedative effects when used with alprazolam. Also, valerian in high doses might modestly increase alprazolam levels, though this is not likely to be clinically significant.
Valerian has sedative effects. Theoretically, valerian might cause additive sedation when combined with alprazolam. Also, a small pharmacokinetic study shows that taking valerian extract 1000 mg daily (providing 11 mg valerenic acid) might increase alprazolam levels by about 19%. This might be due to valerian's mild inhibition of cytochrome P450 3A4 (CYP3A4). Despite being statistically significant, this increase is not likely to be clinically significant.

Likelihood Possible Evidence B
Cns Depressants

Valerian can have additive sedative effects when used concomitantly with CNS depressant drugs.
Theoretically, concomitant use of valerian and drugs with sedative and anesthetic properties may cause additive therapeutic and adverse effects.

Likelihood Possible Evidence D
Glucuronidated Drugs

Valerian might weakly inhibit glucuronidation and increase concentrations of drugs metabolized by UGT1A1 and UGT2B7.
In vitro research shows that methanolic valerian extract and valerenic acid might competitively inhibit UDP-glucuronosyltransferase (UGT) 1A1 (UGT1A1) and UGT2B7.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Valerian does not seem to have a clinically relevant effect on levels of drugs metabolized by CYP2D6.
Although some in vitro evidence suggests that valerian affects CYP2D6, clinical pharmacokinetic (PK) studies show that valerian is unlikely to affect the CYP2D6 enzyme. In one PK study, taking valerian 1000 mg (providing about 11 mg valerenic acid) nightly for 14 days did not affect the metabolism of dextromethorphan, a CYP2D6 substrate. In another PK study, taking valerian 125 mg three times daily for 28 days did not affect metabolism of debrisoquine, an accepted CYP2D6 probe-substrate.

Likelihood Unlikely Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

Valerian does not seem to have a clinically relevant effect on levels of drugs metabolized by CYP3A4.
Although some in vitro evidence suggests that valerian extract might inhibit or induce CYP3A4, clinical pharmacokinetic (PK) studies show that valerian does not have a clinically significant effect on the CYP3A4 enzyme. In one PK study, taking valerian 125 mg three times daily for 28 days did not affect metabolism of midazolam, an accepted CYP3A4 probe-substrate. In another PK study, taking valerian 1000 mg (providing about 11 mg valerenic acid) nightly for 14 days modestly increases levels of alprazolam, a CYP3A4 substrate, suggesting mild inhibition of CYP3A4. However, this mild inhibition is unlikely to be clinically relevant.

Likelihood Possible Evidence B
Valerian root powdered extract full monograph & interactions

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

GABA2 drug types · 419 drugs

Antihypertensive Drugs

Theoretically, taking GABA with antihypertensive drugs might increase the risk of hypotension.
Some clinical research shows that GABA can decrease blood pressure in patients with hypertension.

Likelihood Possible Evidence B
Cns Depressants

Theoretically, GABA might have additive sedative effects when used in conjunction with CNS depressants. However, it is unclear if this concern is clinically relevant.
Endogenous GABA has well-established relaxant effects and GABA(A) receptors have an established physiological role in sleep. However, the effects of GABA supplements are unclear, as it is unknown whether exogenous GABA crosses the blood-brain barrier. Although there have been limited reports of drowsiness or tiredness with GABA supplements, these effects have not been widely reported in clinical studies. Additionally, intravenous GABA 0.1-1 mg/kg has been shown to induce anxiety in a dose-dependent manner.

Likelihood Unlikely Evidence D
GABA full monograph & interactions
The maker

Brand information

Manufacturer and brand details for L-Theanine Complex, from the product label.

Solgar

See all Solgar products
Name
Solgar Vitamin and Herb
City
Leonia
State
N.J.
ZipCode
07605
Phone Number
1-877-765-4274
Web Address
www.solgar.com
Pharmacist Counseling Corner

L-Theanine Complex by Solgar: Common Questions

Does L-Theanine Complex by Solgar interact with any medications?
Yes. Based on its ingredients, L-Theanine Complex has a known interaction with 1,073 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
L-Theanine Complex contains 3 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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 while pregnant or breastfeeding?
No—safety data are not established for all three ingredients during pregnancy or breastfeeding. The facts advise avoiding this product in both cases unless your doctor advises otherwise. Talk with your doctor or pharmacist for personalized guidance.
What are the most common side effects?
Drowsiness is possible from all three ingredients. GABA may cause stomach upset, nausea, muscle weakness, or mild throat burning. L-theanine may cause headaches or vivid dreams. Valerian root commonly causes dizziness, mental slowness, headache, stomach upset, and vivid dreams. These are usually mild, but long-term side effects haven't been well studied.
Is this safe to take long-term?
The data show these ingredients are generally well tolerated short-term, but long-term safety is not well studied for any of them. With valerian especially, chronic use followed by sudden stopping can trigger withdrawal symptoms like anxiety and insomnia—taper slowly if you've used it for a while.
Will this help me sleep?
Valerian root is possibly effective for insomnia based on available evidence. GABA and L-theanine don't have established evidence for sleep, though they may promote relaxation. Individual results vary, and the combination hasn't been specifically tested.
Can I drink alcohol with this?
No—valerian root can have additive sedative effects with alcohol and may cause excessive drowsiness. Avoid alcohol while taking this product.
What is L-theanine for?
L-theanine is an amino acid from tea that has possibly effective evidence for supporting cognitive function. It may promote calm and focus, though it can also cause drowsiness in some people.

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

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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 Complex label
Go deeper

The Full Monographs Behind L-Theanine Complex’s Ingredients

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

Herb & supplement monograph

Gamma-aminobutyric Acid (gaba)

Interacts with 419 drugs

GABA is a calming chemical messenger (neurotransmitter) that your body makes on its own, and it is sold as a supplement for stress, anxiety, and sleep. The science behind oral GABA supplemen...

Read the full Gamma-aminobutyric Acid (gaba) monograph → 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 → Herb & supplement monograph

Valerian

Interacts with 902 drugs

Valerian is an herb whose root is widely used as a natural sleep aid and for calming nerves. The evidence is mixed and often weak, so it may help some people sleep but does not work reliably...

Read the full Valerian monograph →
Sources

Sources & How We Checked

L-Theanine Complex'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 55 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.

Gamma-aminobutyric Acid (gaba) 12 references
  1. Cavagnini F, Invitti C, Pinto M, et al. Effect of acute and repeated administration of gamma aminobutyric acid (GABA) on growth hormone and prolactin secretion in man. Acta Endocrinol (Copenh) 1980;93:149-54.
  2. Nurnberger JI Jr, Berrettini WH, Simmons-Alling S, et al. Intravenous GABA administration is anxiogenic in man. Psychiatry Res 1986;19:113-7. PubMed
  3. Gershman RN, Vasilenko MA, Iliushina GG, et al. [Gammalon in the rehabilitation in infantile cerebral palsy]. Pediatr.Akus.Ginekol. 1977;(6):26-7.
  4. Loeb C, Benassi E, Bo, GP, et al. Preliminary evaluation of the effect of GABA and phosphatidylserine in epileptic patients. Epilepsy Res. 1987;1:209-12 . PubMed
  5. Inoue K, Shirai T, Ochiai H, et al. Blood-pressure-lowering effect of a novel fermented milk containing gamma-aminobutyric acid (GABA) in mild hypertensives. Eur J Clin Nutr 2003;57:490-95.
  6. ELLIOTT, K. A. and JASPER, H. H. Gammaaminobutyric acid. Physiol Rev. 1959;39(2):383-406.
  7. Winsky-Sommerer, R. Role of GABAA receptors in the physiology and pharmacology of sleep. Eur.J.Neurosci. 2009;29(9):1779-1794.
  8. Meldrum, B. S. GABAergic mechanisms in the pathogenesis and treatment of epilepsy. Br.J.Clin.Pharmacol. 1989;27 Suppl 1:3S-11S. PubMed
  9. Loeb, C., Marinari, U. M., Benassi, E., Besio, G., Cottalasso, D., Cupello, A., Maffini, M., Mainardi, P., Pronzato, M. A., and Scotto, P. A. Phosphatidylserine increases in vivo the synaptosomal uptake of exogenous GABA in rats. Exp.Neurol. 1988;99(2):4 PubMed
  10. Melis, G. B., Paoletti, A. M., Mais, V., and Fioretti, P. Interference of dopamine infusion on gamma-amino butyric acid (GABA)-stimulated prolactin increase. J.Endocrinol.Invest 1980;3(4):445-448.
  11. Boonstra E, de Kleijn R, Colzato LS, Alkemade A, Forstmann BU, Nieuwenhuis S. Neurotransmitters as food supplements: the effects of GABA on brain and behavior. Front Psychol. 2015 Oct 6;6:1520. doi: 10.3389/fpsyg.2015.01520. eCollection 2015. PubMed
  12. de Bie TH, Witkamp RF, Balvers MG, Jongsma MA. Effects of ?-aminobutyric acid supplementation on glucose control in adults with prediabetes: A double-blind, randomized, placebo-controlled trial. Am J Clin Nutr 2023;118(3):708-719. PubMed

See these in context on the Gamma-aminobutyric Acid (gaba) monograph →

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 →

Valerian 37 references
  1. Willey LB, Mady SP, Cobaugh DJ, Wax PM. Valerian overdose: a case report. Vet Hum Toxicol 1995;37:364-5.
  2. Kuhlmann J, Berger W, Podzuweit H, Schmidt U. The influence of valerian treatment on "reaction time, alertness and concentration" in volunteers. Pharmacopsychiatry 1999;32:235-41. PubMed
  3. Klepser TB, Klepser ME. Unsafe and potentially safe herbal therapies. Am J Health Syst Pharm 1999;56:125-38. PubMed
  4. Houghton PJ. The scientific basis for the reputed activity of Valerian. J Pharm Pharmacol 1999;51:505-12. PubMed
  5. Garges HP, Varia I, Doraiswamy PM. Cardiac complications and delirium associated with Valerian root withdrawal. [Letter to the Editor]. JAMA 1998;280:1566-7. PubMed
  6. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  7. MacGregor FB, Abernethy VE, Dahabra S, et al. Hepatotoxicity of herbal remedies. BMJ 1989;299:1156-7. PubMed
  8. Leathwood PD, Chauffard F. Aqueous extract of valerian reduces latency to fall asleep in man. Planta Med 1985;2:144-8. PubMed
  9. Hadley S, Petry JJ. Valerian. Am Fam Physician 2003;67:1755-8..
  10. Glass JR, Sproule BA, Herrmann N, et al. Acute pharmacological effects of temazepam, diphenhydramine, and valerian in healthy elderly subjects. J Clin Psychopharmacol 2003;23:260-8. PubMed
  11. Lefebvre T, Foster BC, Drouin CE, et al. In vitro activity of commercial valerian root extracts against human cytochrome P450 3A4. J Pharm Pharmaceut Sci 2004;7:265-73.
  12. Yuan CS, Mehendale S, Xiao Y, et al. The gamma-aminobutyric acidergic effects of valerian and valerenic acid on rat brainstem neuronal activity. Anesth Analg 2004;98:353-8. PubMed
  13. Donovan JL, DeVane CL, Chavin KD, et al. Multiple night-time doses of valerian (Valeriana officinalis) had minimal effects on CYP3A4 activity and no effect on CYP2D6 activity in healthy volunteers. Drug Metab Dispos 2004;32:1333-6. PubMed
  14. Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo effects of goldenseal, kava kava, black cohosh, and valerian on human cytochrome P450 1A2, 2D6, 2E1, and 3A4/5 phenotypes. Clin Pharmacol Ther 2005;77:415-26. PubMed
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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.

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