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Dietary supplement

Natural L-Tyrosine 500 mg Ingredients & Drug Interactions

by Rugby

Natural L-Tyrosine 500 mg 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 Natural L-Tyrosine 500 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

Natural L-Tyrosine 500 mg is a dietary supplement by Rugby 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 Natural L-Tyrosine 500 mg by Rugby

Ask about any prescription or over-the-counter medication and we check it for interactions with Natural L-Tyrosine 500 mg by Rugby — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Natural L-Tyrosine 500 mg by Rugby

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 27, 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.

Natural L-Tyrosine 500 mg contains one active ingredient: L-tyrosine, an amino acid (a building block your body uses to make proteins and certain chemical messengers in the brain). The capsule also holds inactive ingredients—gelatin, dicalcium phosphate, maltodextrin, and vegetable magnesium stearate—that serve as a filler, binder, and capsule material.

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).

The evidence for L-tyrosine is mixed and depends on what you're using it for. It's rated effective for phenylketonuria (PKU), a rare genetic condition.

For cognitive function and memory, it's possibly effective, meaning some evidence suggests benefit but it's not definitive. For athletic performance, the evidence suggests it's likely ineffective.

For alcohol use disorder and dementia, there's not 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, but talk with your healthcare provider before you start taking it regularly. The most common side effects reported are fatigue, headache, heartburn, and nausea—especially at higher doses.

There isn't enough safety data on long-term use, so avoid supplemental doses unless your doctor recommends it. Safety data during breastfeeding is also limited, so if you're breastfeeding, discuss this supplement with your doctor or pharmacist before starting.

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.

Check before taking this product if you use levodopa (Moderate interaction—tyrosine may lower its effectiveness, so doses need to be separated) or thyroid hormone medications like levothyroxine (Moderate interaction—tyrosine might amplify thyroid hormone effects). Your pharmacist or doctor can advise on timing or whether this supplement is right for you.

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.

This single-ingredient supplement may be worth considering if you're interested in possible cognitive or memory support and don't take levodopa or thyroid medications. If you do take either of those drugs, or any other prescription medication, talk it over with your doctor or pharmacist before adding L-tyrosine—especially to make sure the timing won't interfere with how your other drugs work.

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 Natural L-Tyrosine 500 mg, straight from the product label.

Brand Rugby
Barcode (UPC) 005361032066
Net contents 50 Capsule(s)
Market status On market
Date entered into DSLD Apr 25, 2019
DSLD ID 200946
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years), Gluten 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 Natural L-Tyrosine 500 mg by Rugby, 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
005361032066
IngredientAmount% DV
L-Tyrosine500 mg--

Other ingredients: Gelatin, Dicalcium Phosphate, Maltodextrin, Vegetable 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.
FDA Statement of Identity

Amino Acid Supplement

Precautions

Tamper resistant - Do not use if imprinted safety seal under cap is broken or missing

Keep out of reach of children

Suggested/Recommended/Usage/Directions

Directions: One capsule daily.

Formulation

Free of: Starch, sugar, sodium, preservatives, gluten, soy, yeast, artificial colors-flavors.

Storage

To preserve quality and freshness, keep bottle tightly closed. Store between 15(0)-30(0)C (59(0)-86(0)F).

General Statements

100

General

Rev. 03/16 R-92 Re-order No.370359

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

See for yourself

Natural L-Tyrosine 500 mg by Rugby label

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

Natural L-Tyrosine 500 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 Natural L-Tyrosine 500 mg by Rugby

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: Gelatin, Dicalcium Phosphate, Maltodextrin, Vegetable Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Natural L-Tyrosine 500 mg by Rugby Drug Interactions

Want to check YOUR meds against Natural L-Tyrosine 500 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
21Drugs
21 Moderate

Ingredients driving the most interactions

L-Tyrosine 21

Individual Drug Interactions

The ingredients in Natural L-Tyrosine 500 mg interact with 21 drugs. Click any drug to see the details.

1 of the 1 ingredient in Natural L-Tyrosine 500 mg 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 Natural L-Tyrosine 500 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.

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 Natural L-Tyrosine 500 mg, from the product label.

Rugby

See all Rugby products
Name
Rugby Laboratories
Street Address
31778 Enterprise Drive
City
Livonia
State
MI
ZipCode
48150
Phone Number
1-800-645-2158
Web Address
www.rugbylaboratories.com
Pharmacist Counseling Corner

Natural L-Tyrosine 500 mg by Rugby: Common Questions

Does Natural L-Tyrosine 500 mg by Rugby interact with any medications?
Yes. Based on its ingredients, Natural L-Tyrosine 500 mg 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?
Natural L-Tyrosine 500 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.
What does L-tyrosine actually do in my body?
L-tyrosine is an amino acid your body uses to make proteins and chemical messengers in the brain. It's a precursor to thyroid hormones and to dopamine, a brain chemical involved in mood, focus, and motivation.
Is it safe to take L-tyrosine if I have a thyroid condition?
L-tyrosine can add to the effects of thyroid hormones, so if you take thyroid medication, talk with your doctor or pharmacist first. They may want to monitor your thyroid levels or adjust your medication timing.
Will this help my memory or focus?
The evidence for L-tyrosine on memory and cognitive function is rated possibly effective—meaning some studies show promise, but it's not definitive yet. Results vary, and your own experience may differ.
Can I take L-tyrosine while breastfeeding?
There isn't enough safety data to know whether supplemental L-tyrosine is safe during breastfeeding. Talk with your doctor or pharmacist before starting, so they can give you personalized advice based on your situation.
What are the most common side effects?
Fatigue, headache, heartburn, and nausea are the side effects most often reported. These tend to happen at higher doses and can usually be reduced by lowering how much you take.
Do I need to worry about fillers in this capsule?
This capsule contains gelatin, dicalcium phosphate, maltodextrin, and vegetable magnesium stearate as inactive ingredients. If you have sensitivities to any of these, check the label first.

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

Not sure if Natural L-Tyrosine 500 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.

Natural L-Tyrosine 500 mg label
Go deeper

The Full Monographs Behind Natural L-Tyrosine 500 mg’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

Natural L-Tyrosine 500 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 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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