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Dietary supplement

L-Tyrosine 750 mg - Extra Strength Ingredients & Drug Interactions

by NOW

L-Tyrosine 750 mg - Extra Strength 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 750 mg - Extra Strength 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 750 mg - Extra Strength is a dietary supplement by NOW 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 750 mg - Extra Strength by NOW

Ask about any prescription or over-the-counter medication and we check it for interactions with L-Tyrosine 750 mg - Extra Strength by NOW — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of L-Tyrosine 750 mg - Extra Strength by NOW

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 a single active ingredient: L-tyrosine, an amino acid your body uses to make neurotransmitters (brain chemicals) and thyroid hormone. The 750 mg dose is delivered in a capsule with inactive ingredients—cellulose, rice flour, stearic acid, and silica—which 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: neurotransmitter production for mental focus and mood.
  • We looked for evidence on: Cognitive function, Memory, Fatigue, Sleep deprivation, Stress, Depression — and 3 related terms.
  • The strongest evidence on file: Tyrosine is rated "Possibly Effective" for Cognitive function (Natural Medicines).
  • Also on file: Tyrosine is rated "Possibly Effective" for Memory.
  • Also on file: Tyrosine is rated "Possibly Ineffective" for Athletic performance.

L-tyrosine is effective for phenylketonuria (PKU), a metabolic condition. It's possibly effective for cognitive function and memory.

For athletic performance, the evidence leans toward it not being effective. The data we hold doesn't establish reliable evidence 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, but you should talk to a healthcare provider before taking it regularly. The most common side effects reported are fatigue, headache, heartburn, and nausea.

At higher doses (150 mg/kg), headache and fatigue are more likely. There isn't enough safety data on supplemental doses during pregnancy or breastfeeding, so talk with your doctor or pharmacist for personalized advice 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.

Double-check this product if you're on levodopa (a Parkinson's medication) or any thyroid hormone medication—both are Moderate-severity interactions. Space levodopa doses at least 2 hours from the tyrosine if your doctor says it's okay to use both.

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 may help with cognitive function and memory, and it's established for PKU. If you take levodopa for Parkinson's or any thyroid medication, check with your doctor or pharmacist first—this supplement can interfere with how those drugs work.

For most other people, it's generally well tolerated, but side effects like headache, fatigue, and nausea do happen.

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 Feb 23, 2016.

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 750 mg - Extra Strength, straight from the product label.

Brand NOW
Barcode (UPC) 733739001658
Net contents 90 Veg Capsule(s)
Market status On market
Date entered into DSLD Feb 23, 2016
DSLD ID 56821
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy 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 750 mg - Extra Strength by NOW, 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 Veg Capsule(s)
Maximum serving Sizes:
1 Veg Capsule(s)
UPC/BARCODE
733739001658
IngredientAmount% DV
L-Tyrosine750 mg--

Other ingredients: Cellulose, Rice Flour, Stearic Acid, 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.
Suggested/Recommended/Usage/Directions

Suggested Usage: Take 1 capsule 1 to 3 times daily, preferably between meals.

General Statements

L-Tyrosine is a conditionally indispensable amino acid required for the production of the neurotransmitters dopamine, adrenaline, and noradrenaline, as well as for the skin pigment, melanin.* Noradrenaline (norepinephrine) and adrenaline (epinephrine) are the main actors in the body’s response to acute stress and, along with dopamine, help to support a positive mood and mental alertness.* In addition, L-Tyrosine is especially critical for the normal function of the thyroid gland.*

Natural color variation may occur in this product.

CAPSULE SIZE

Neurotransmitter Support*

~ Pharmaceutical Grade ~ Healthy Glandular Function* ~ Supports Mental Alertness*

Amino Acids

Family owned since 1968.

The L-Tyrosine used in this product is Pharmaceutical Grade. Natural color variation may occur in this product.

Please Recycle.

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.

Precautions

Caution: For adults only.

Consult physician if pregnant/nursing, taking medication, or have a medical condition. Persons with thyroid disease (hyperthyroidism), melanoma, or those taking MAO inhibitors or other mood altering medications should seek the advice of a physician before consuming this product.

Keep out of reach of children.

Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

Seals/Symbols

Non-GMO

GMP QUALITY ASSURED

FDA Statement of Identity

A Dietary Supplement

Formulation

Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients.

Storage

Store in a cool, dry place after opening.

Formula

This extra strength product has more L-Tyrosine (750 mg per capsule) than our regular strength product (500 mg per capsule).

General

CODE 0165B V4

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

See for yourself

L-Tyrosine 750 mg - Extra Strength by NOW label

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

L-Tyrosine 750 mg - Extra Strength 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 750 mg - Extra Strength by NOW

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

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

L-Tyrosine

Interacts with
21 drugs
750 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: Cellulose, Rice Flour, Stearic Acid, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Tyrosine 750 mg - Extra Strength by NOW Drug Interactions

Want to check YOUR meds against L-Tyrosine 750 mg - Extra Strength?

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 750 mg - Extra Strength interact with 21 drugs. Click any drug to see the details.

1 of the 1 ingredient in L-Tyrosine 750 mg - Extra Strength 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 750 mg - Extra Strength 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 750 mg - Extra Strength, from the product label.

NOW

See all NOW products
Name
NOW Foods
Street Address
395 S. Glen Ellyn Rd.
City
Bloomingdale
State
IL
ZipCode
60108
Web Address
nowfoods.com
Pharmacist Counseling Corner

L-Tyrosine 750 mg - Extra Strength by NOW: Common Questions

Does L-Tyrosine 750 mg - Extra Strength by NOW interact with any medications?
Yes. Based on its ingredients, L-Tyrosine 750 mg - Extra Strength 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 750 mg - Extra Strength 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 and what does it do?
L-tyrosine is an amino acid—a building block your body uses to make brain chemicals (neurotransmitters) and thyroid hormone. Your body can make some of its own, but supplementing it may support cognitive function and memory.
Will this help me think better or remember things?
L-tyrosine is possibly effective for cognitive function and memory based on the data we hold, so it may help—but the evidence isn't as strong as it is for some other supplements. Results vary from person to person.
Can I take this while pregnant or breastfeeding?
There isn't enough safety data on supplemental tyrosine doses during pregnancy or breastfeeding. Talk with your doctor or pharmacist about whether it's right for you in those situations.
What side effects might I notice?
Fatigue, headache, heartburn, and nausea are the most common. They're usually mild, but if you're taking a higher dose, headache and fatigue become more likely. Starting with a lower dose may help.
Is this safe to take every day?
L-tyrosine is generally well tolerated in healthy adults, but there isn't enough safety data to say definitively that regular supplemental doses are safe long-term. Talk to a healthcare provider before taking it regularly.

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

Not sure if L-Tyrosine 750 mg - Extra Strength 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 750 mg - Extra Strength label
Go deeper

The Full Monographs Behind L-Tyrosine 750 mg - Extra Strength’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 750 mg - Extra Strength'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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