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Dietary supplement

L-Tyrosine Ingredients & Drug Interactions

by Biotics Research Corporation

Capsule Category: Amino Acid/protein
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

L-Tyrosine is a dietary supplement by Biotics Research Corporation 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.

HelloPharmacist Scorecard of L-Tyrosine by Biotics Research Corporation

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

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 hormones. The capsule also holds gelatin, water, and glycerin as inactive ingredients that help deliver the dose.

L-tyrosine is naturally present in protein-rich foods, and supplemental doses are used to support alertness and cognitive function in certain situations — though the evidence for some uses is still being established.

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 genetic condition that affects how your body processes amino acids. It's possibly effective for cognitive function and memory, meaning the evidence suggests it may help but isn't conclusive yet.

For athletic performance, the evidence suggests it probably doesn't help. 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, but the facts advise talking to your healthcare provider before you use it regularly. The most common side effects people report are fatigue, headache, heartburn, and nausea — and at higher doses, these effects can intensify.

There isn't enough safety data on supplemental tyrosine during pregnancy or breastfeeding; talk with your doctor or pharmacist before taking it during either time.

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, check with your doctor or pharmacist if you take levodopa (Moderate interaction — tyrosine may reduce its effectiveness; separate doses by 2 hours) or thyroid hormone replacement therapy like levothyroxine (Moderate interaction — additive thyroid hormone effects). Use the search tool below to confirm your medications.

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, and it's effective for PKU when prescribed by a doctor. If you take levodopa for Parkinson's or thyroid hormone medication, check with your doctor or pharmacist first — this supplement can interfere with both.

For most healthy adults with no medications, it's generally well tolerated, but start with a conversation about whether you really need it.

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 May 24, 2013.

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 Biotics Research Corporation
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD May 24, 2013
DSLD ID 21943
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses All Other
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 Biotics Research Corporation, 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)
IngredientAmount% DV
L-Tyrosine500 mg--

Other ingredients: Gelatin, Water, Glycerin

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.
Brand IP Statement(s)

(C) Copyright 2010

General Statements

Lot Number: 33975A Exp. Date: OCT 11

CERTIFIED PURE

Suggested/Recommended/Usage/Directions

RECOMMENDATION: One (1) capsule (3) times each day as a dietary supplement or as otherwise directed by a healthcare professional.

Precautions

KEEP OUT OF REACH OF CHILDREN

Sealed with an imprinted safety seal for your protection.

Storage

Store in a cool, dry area.

General

Rev. 3/07

FDA Statement of Identity

Amino Acid Supplement

Formula

L-Tyrosine is a non-hydrolyzed free form amino acid.

See for yourself

L-Tyrosine by Biotics Research Corporation label

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

What’s inside

The Ingredients in L-Tyrosine by Biotics Research Corporation

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, Water, Glycerin. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Tyrosine by Biotics Research Corporation 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

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
The maker

Brand information

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

Biotics Research Corporation

See all Biotics Research Corporation products
Name
BIOTICS RESEARCH CORP.
City
Rosenberg
State
Texas
Phone Number
(281) 344-0909
Pharmacist Counseling Corner

L-Tyrosine by Biotics Research Corporation: Common Questions

Does L-Tyrosine by Biotics Research Corporation 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 actually for?
L-tyrosine is an amino acid your body converts into neurotransmitters that support alertness and brain function, and into thyroid hormones. The research shows it works for PKU, and may help with cognitive function and memory, though evidence for memory support isn't definitive yet.
What are the side effects?
The most common ones are fatigue, headache, heartburn, and nausea. These are mild and happen at normal doses. At much higher doses (150 mg/kg or larger), headache and fatigue can worsen. If you experience any of these, lowering your dose often helps.
Is it safe to take while I'm pregnant or breastfeeding?
There isn't enough safety data to know either way. Talk with your doctor or pharmacist for personalized advice before taking L-tyrosine during pregnancy or breastfeeding.
Can I take it with my Parkinson's medication?
If you take levodopa, talk with your doctor first. L-tyrosine and levodopa compete for absorption, so tyrosine might make levodopa less effective. Your doctor may recommend spacing them 2 hours apart, or may suggest you skip this supplement.
Will it help my athletic performance?
The evidence suggests it probably won't. While L-tyrosine supports mental function in some situations, research doesn't show it boosts athletic performance.
Is this safe to take every day?
L-tyrosine is generally well tolerated for regular use in healthy adults, but the data available isn't extensive. Talk with your healthcare provider before starting daily supplementation to make sure it's right for you.

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-Tyrosine label
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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