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Dietary supplement

L-Tyrosine Ingredients & Drug Interactions

by Vitamin Research Products

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 Vitamin Research Products 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 Vitamin Research Products

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

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HelloPharmacist Scorecard of L-Tyrosine by Vitamin Research Products

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 your body uses to make neurotransmitters and thyroid hormone. The capsule also includes two inactive ingredients — hydroxypropylmethylcellulose and magnesium stearate — which are binders and flow agents.

Does it work?

Strong 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

This product doesn't appear to be marketed for a specific use, so we graded Tyrosine's overall clinical evidence instead.

Strong

Strong clinical evidence supports Tyrosine for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Phenylketonuria (PKU) — rated "Effective" (Natural Medicines).
  • On file: Cognitive function — rated "Possibly Effective" (Natural Medicines).
  • On file: Memory — rated "Possibly Effective" (Natural Medicines).

L-tyrosine is effective for phenylketonuria (PKU), a rare genetic condition. It's possibly effective for cognitive function and memory in some people.

The evidence doesn't support its use for athletic performance, and there isn't enough reliable evidence to rate it for alcohol use disorder or dementia.

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 you should talk with a healthcare provider before taking it regularly. Common side effects at normal doses include fatigue, headache, heartburn, and nausea.

Larger doses (150 mg/kg) can increase headache and fatigue; these effects usually improve if you lower the dose. There isn't enough safety data on supplemental doses during pregnancy, so talk with your doctor or pharmacist before taking it if you're pregnant.

Similarly, safety data during breastfeeding is limited — check with your doctor or pharmacist for personalized advice.

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 you start L-tyrosine, double-check with your doctor or pharmacist if you take levodopa (a Parkinson's medication) — separate the doses by at least 2 hours. Also flag any thyroid hormone medications, as tyrosine might boost their effect.

Both interactions are Moderate in severity.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

L-tyrosine may help with cognitive function and memory, though the evidence is mixed. If you take levodopa for Parkinson's disease or any thyroid medication, talk with your doctor or pharmacist before starting — timing and dosing matter.

It's generally well tolerated, but work with your own healthcare provider to decide if it's right for you.

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 25, 2014.

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 Vitamin Research Products
Barcode (UPC) 810832010845
Net contents 90 Capsule(s)
Market status On market
Date entered into DSLD Jun 25, 2014
DSLD ID 34094
Product type Amino Acid/protein
Supplement form Capsule
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 L-Tyrosine by Vitamin Research Products, 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)
UPC/BARCODE
810832010845
IngredientAmount% DV
L-Tyrosine500 mg--

Other ingredients: Hydroxypropylmethylcellulose, Magnesium Stearate

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.
Suggested/Recommended/Usage/Directions

Directions: Take 1 capsule up to two times per day on an empty stomach.

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.

General Statements

This product is manufactured in a NSF GMP registered facility.

Since 1979

TESTED FOR QUALITY & PURITY

Code Number: 4701

Description: L-Tyrosine is a precursor to several neurotransmitters including dopamine, norpinephrine and epinephrine. L-Tyrosine's effect on neurotransmitters make it helpful for maintaining a positive mood.

Seals/Symbols

LABORATORY TESTED QUALITY & PURITY

VRP

General

300-VRP4701-G

FDA Statement of Identity

Dietary Supplement

Storage

Keep container tightly closed in a cool, dry and dark place.

Precautions

Keep out of reach of children.

Caution: If you are under a physician's care or taking medications, or if you are pregnant or nursing, consult your healthcare professional before using this product.

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

See for yourself

L-Tyrosine by Vitamin Research Products 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 Vitamin Research Products

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

Serving size1 Capsule(s) Dosage formCapsule 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: Hydroxypropylmethylcellulose, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Tyrosine by Vitamin Research Products 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.

Vitamin Research Products

See all Vitamin Research Products products
Name
VRP Brand, LLC
Street Address
4610 Arrowhead Dr.
City
Carson City
State
NV
ZipCode
89706
Phone Number
1-800-877-2447
Web Address
www.vrp.com
Pharmacist Counseling Corner

L-Tyrosine by Vitamin Research Products: Common Questions

Does L-Tyrosine by Vitamin Research Products 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.
What is L-tyrosine supposed to do?
L-tyrosine is an amino acid your body uses to make neurotransmitters and thyroid hormone. It's effective for PKU, a rare genetic disorder, and possibly helpful for cognitive function and memory, though the research is still limited.
Can I take this if I'm pregnant or breastfeeding?
There isn't enough safety data to say either way during pregnancy or breastfeeding. Talk with your doctor or pharmacist for personalized advice before taking it.
What side effects might I notice?
At normal doses, some people experience fatigue, headache, heartburn, or nausea. These are usually mild. Higher doses are more likely to cause headache and fatigue, but lowering the dose typically helps.
I take levodopa for Parkinson's. Can I use this supplement?
Tyrosine and levodopa compete for absorption and could make your levodopa less effective. You'd need to separate the doses by at least 2 hours. Talk with your doctor or pharmacist about whether it's okay for you and how to time it.
I'm on thyroid medication. Is this supplement safe?
Tyrosine is a building block for thyroid hormones and might increase their levels in your body. Your doctor or pharmacist should review your thyroid dose if you want to start taking tyrosine regularly.
Will this help with athletic performance?
The evidence doesn't support L-tyrosine for athletic performance, so it's probably not going to help with that goal.

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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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.

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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