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Dietary supplement

L-Tyrosine Ingredients & Drug Interactions

by DaVinci Laboratories of Vermont

L-Tyrosine label
See full label image
Capsule Category: Amino Acid/protein
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking L-Tyrosine 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-Tyrosine is a dietary supplement by DaVinci Laboratories of Vermont with 1 active ingredient. Its ingredients are commonly taken for mental focus and alertness, coping with stress, fatigue and sleep loss.Based on those ingredients, 21 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are L-Tyrosine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against L-Tyrosine by DaVinci Laboratories of Vermont

Ask about any prescription or over-the-counter medication and we check it for interactions with L-Tyrosine by DaVinci Laboratories of Vermont — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of L-Tyrosine by DaVinci Laboratories of Vermont

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 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: L-tyrosine, an amino acid that your body uses to make several important compounds, including neurotransmitters and thyroid hormones. The capsule also holds inactive ingredients — vegetable cellulose, microcrystalline cellulose, silicon dioxide, and leucine — which are fillers and binders that help form and stabilize the capsule.

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: Support mood balance, stress management, and thyroid function.
  • We looked for evidence on: Stress, Fatigue, Sleep deprivation, Athletic performance, Cognitive function, Depression — and 2 related terms.
  • The strongest evidence on file: Tyrosine is rated "Possibly Effective" for Cognitive function (Natural Medicines).
  • Also on file: Tyrosine is rated "Possibly Ineffective" for Athletic performance.
  • Also on file: Tyrosine is rated "Insufficient Reliable Evidence To Rate" for Depression, Fatigue, Sleep deprivation, Stress.

L-Tyrosine is effective for phenylketonuria (PKU), a genetic condition in which the body cannot process phenylalanine properly. It is possibly effective for cognitive function and memory — the evidence suggests benefit, but more research is needed to be certain.

For athletic performance, the evidence indicates it's likely not effective. For alcohol use disorder and dementia, there isn't enough reliable evidence yet to say whether it works.

The evidence, ingredient by ingredient Tyrosine

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-Tyrosine is generally well tolerated in healthy adults, though a complete safety evaluation hasn't been done. The most common side effects reported are fatigue, headache, heartburn, and nausea, especially at higher doses.

There isn't enough safety data to recommend regular supplemental use without a doctor's guidance, and safety during breastfeeding hasn't been established — talk with your doctor or pharmacist before taking it if you're pregnant or nursing.

Side effects, ingredient by ingredient Tyrosine

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 — Tyrosine.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: Parkinson's medications.
  • For scale: 21 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 L-Tyrosine, double-check with your doctor or pharmacist if you take levodopa (used for Parkinson's disease) or any thyroid hormone medication — both have documented Moderate-severity interactions with tyrosine. Separating doses by 2 hours and monitoring thyroid hormone levels may help, but your own healthcare provider needs to make that call.

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-Tyrosine is worth considering if you have PKU or want to explore support for memory and focus, but it's not proven for athletic performance. If you take levodopa for Parkinson's or any thyroid hormone medication, you'll need to check with your doctor or pharmacist first — the timing and interactions matter.

Start this conversation with your own healthcare provider before adding it to your routine.

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 Jul 27, 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

At a glance

General information

Key facts about L-Tyrosine, straight from the product label.

Brand DaVinci Laboratories of Vermont
Barcode (UPC) 026664228666
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD Jul 27, 2021
DSLD ID 245101
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegetarian, Adult (18 - 50 Years), Gluten 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-Tyrosine by DaVinci Laboratories of Vermont, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
60
UPC/BARCODE
026664228666
IngredientAmount% DV
L-Tyrosine500 mg--

Other ingredients: Vegetable Cellulose, Microcrystalline Cellulose, Silicon Dioxide, Leucine

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.
General Statements

Truth We pledge total truth in labeling. Our family of products contains only the purest and most potent ingredients. Guaranteed.

Formulation

Color of this product may vary due to color variations of the natural ingredients.

Vegetarian

Gluten free

A Dietary Supplement to Support Mood Balance, Stress Management, and Low Thyroid Function

Precautions

Warning: If taking thyroid medications or have hyperthyroidism or Grave's disease, do not take this product. Warning: If pregnant or nursing, consult your healthcare practitioner before taking this product.

Keep out of reach of children.

To obtain product information or report a serious adverse event, call 1-800-325-1776.

Storage

Store in a cool, dry place.

FDA Disclaimer Statement

This statement has 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

A Dietary Supplement to Support Mood Balance, Stress Management, and Low Thyroid Function

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take 1 capsule, 1 to 2 times daily, between meals, or as directed by your healthcare practitioner.

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

See for yourself

L-Tyrosine by DaVinci Laboratories of Vermont label

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

L-Tyrosine 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-Tyrosine by DaVinci Laboratories of Vermont

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container60 Amounts shown are per serving.

L-Tyrosine

Interacts with
21 drugs
500 mg per serving

L-tyrosine is an amino acid your body uses to make brain chemicals like dopamine and norepinephrine. Some studies suggest it may help mental performan...

L-Tyrosine monograph & interactions

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

Interaction report

L-Tyrosine by DaVinci Laboratories of Vermont Drug Interactions

Want to check YOUR meds against L-Tyrosine?

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
21Drugs
21 Moderate

Ingredients driving the most interactions

L-Tyrosine 21

Individual Drug Interactions

The ingredients in L-Tyrosine interact with 21 drugs. Click any drug to see the details.

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

Each ingredient & the kinds of drugs it affects

For each ingredient in L-Tyrosine with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

L-Tyrosine2 drug types · 21 drugs

Levodopa

Theoretically, tyrosine might decrease the effectiveness of levodopa.
Tyrosine and levodopa compete for absorption in the proximal duodenum by the large neutral amino acid (LNAA) transport system. Advise patients to separate doses of tyrosine and levodopa by at least 2 hours.

Likelihood Probable Evidence D
Thyroid Hormone

Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Tyrosine is a precursor to thyroxine and might increase levels of thyroid hormones.

Likelihood Probable Evidence D
L-Tyrosine full monograph & interactions
The maker

Brand information

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

DaVinci Laboratories of Vermont

Name
DaVinci Laboratories of Vermont a division of FoodScience Corp.
Street Address
929 Harvest Lane
City
Williston
State
VT
ZipCode
05495
Phone Number
1-800-325-1776
Web Address
www.davincilabs.com
Pharmacist Counseling Corner

L-Tyrosine by DaVinci Laboratories of Vermont: Common Questions

Does L-Tyrosine by DaVinci Laboratories of Vermont interact with any medications?
Yes. Based on its ingredients, L-Tyrosine has a known interaction with 21 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
L-Tyrosine 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 while I'm pregnant or breastfeeding?
There isn't enough safety data on L-Tyrosine during pregnancy or breastfeeding. Talk with your doctor or pharmacist to weigh the pros and cons before taking it if you're pregnant or nursing — they know your individual situation and can give you personalized advice.
What are the most common side effects?
Fatigue, headache, heartburn, and nausea are the most commonly reported side effects, especially at higher doses. These tend to be mild, but if you experience them, lowering your dose or stopping the supplement usually resolves them.
Does this actually improve memory and focus?
L-Tyrosine is possibly effective for cognitive function and memory — meaning the evidence suggests it may help, but we need more research to be certain. Results vary from person to person.
Will it help my athletic performance?
The evidence suggests L-Tyrosine is likely not effective for athletic performance, so it's probably not the right choice if that's your main goal.
Why do I need to separate L-Tyrosine from my levodopa dose?
Both tyrosine and levodopa use the same absorption pathway in your small intestine, so they compete with each other. Separating them by at least 2 hours helps levodopa get absorbed properly and work as intended.
Is there anything in this capsule besides L-Tyrosine?
The capsule contains inactive ingredients — vegetable cellulose, microcrystalline cellulose, silicon dioxide, and leucine — which help form and stabilize it. L-Tyrosine is the only active ingredient.

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

Not sure if L-Tyrosine is safe with your meds?

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

L-Tyrosine label
Go deeper

The Full Monographs Behind L-Tyrosine’s Ingredients

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

Herb & supplement monograph

Tyrosine

Interacts with 21 drugs

L-tyrosine is an amino acid your body uses to make brain chemicals like dopamine and norepinephrine. Some studies suggest it may help mental performance during short-term stress, sleep loss,...

Read the full Tyrosine monograph →
Sources

Sources & How We Checked

L-Tyrosine'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 4 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.

Tyrosine 4 references
  1. Meyer JS, Welch KM, Deshmukh VD, et al. Neurotransmitter precursor amino acids in the treatment of multi-infarct dementia and Alzheimer's disease. J Amer Geriat Soc 1977;25:289-98.
  2. DiPiro JT, Talbert RL, Yee GC, et al; eds. Pharmacotherapy: A pathophysiologic approach. 4th ed. Stamford, CT: Appleton & Lange, 1999.
  3. Wood DR, Reimherr FW, Wender PH. Amino acid precursors for the treatment of attention deficit disorder, residual type. Psychopharmacol Bull 1985;21:146-9.
  4. van Spronsen FJ, van Rijn M, Bekhof J. Phenylketonuria: tyrosine supplementation in phenylalanine-restricted diets. Am J Clin Nutr 2001;73:153-7. PubMed

See these in context on the Tyrosine 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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