L-Tyrosine Ingredients & Drug Interactions
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
L-Tyrosine is a dietary supplement by BulkSupplements.com 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.
Check Your Meds Against L-Tyrosine by BulkSupplements.com
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Tyrosine by BulkSupplements.com — and tell you which ingredient is responsible.
AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of L-Tyrosine by BulkSupplements.com
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.
What’s inside
Full disclosure
This product contains one active ingredient: L-tyrosine, an amino acid your body uses to make neurotransmitters (brain chemicals) and thyroid hormones. There are no inactive ingredients listed.
Does it work?
Moderate evidence
L-tyrosine is effective for phenylketonuria (PKU), a genetic condition where the body can't process another amino acid properly. It's possibly effective for cognitive function and memory — some research suggests it may help with focus and recall.
For athletic performance, the evidence doesn't support a benefit. For alcohol use disorder and dementia, there isn't enough reliable evidence yet to know whether it works.
How safe is it?
Well-documented data
Tyrosine is generally well tolerated in healthy adults, but we don't have enough long-term safety data, so talk to your doctor before using it regularly. The most common side effects in trials were fatigue, headache, heartburn, and nausea.
At higher doses (150 mg per kilogram of body weight), headache and fatigue became more likely. There isn't enough safety data for pregnancy, and we can't advise either way — talk with your doctor or pharmacist for personalized guidance.
For breastfeeding, caution is advised due to limited safety information.
Meds to double-check
Moderate interaction found
Check with your pharmacist if you take levodopa (Parkinson's medication) — separate your doses by at least 2 hours. Also double-check if you're on thyroid hormone medications, since tyrosine might increase their effect.
Use the medication search tool on this page to verify your exact prescriptions.
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 focus and memory in healthy adults, and it's proven for PKU. If you take levodopa or thyroid hormone medication, you'll need to check with your pharmacist first.
Stick with your doctor's guidance on dose and duration, especially if you're pregnant, breastfeeding, or have ongoing health concerns.
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 Oct 24, 2024.
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
General information
Key facts about L-Tyrosine, straight from the product label.
| Brand | BulkSupplements.com |
|---|---|
| Barcode (UPC) | X000HSSKC1 |
| Net contents | 250 Gram(s); 8.8 Ounce(s) |
| Market status | On market |
| Date entered into DSLD | Oct 24, 2024 |
| DSLD ID | 312290 |
| Product type | Amino Acid/protein |
| Supplement form | Powder |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years), Gluten Free, Dairy Free |
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 BulkSupplements.com, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Tyrosine | 1000 mg | -- |
Tap any ingredient to jump to its full detail below.
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)
Bulksupplements.com Clean & pure bulk supplements
Formulation
Free of: Added sugar, soy, dairy, yeast, gluten, additives
Suggested/Recommended/Usage/Directions
Suggested use: As a dietary supplement, take 1000 mg (about 2/5 tsp) one to three times daily, or as directed by a physician.
General Statements
Use an accurate milligram scale.
New
Storage
Contents are sold by weight, not volume. Settling may occur. Store in a dry, cool place
FDA Disclaimer Statement
Warning: This product is not intended to diagnose, treat, cure, or prevent any disease.
Precautions
Always consult a physician before taking any dietary supplement.
Keep out of reach of children.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Tyrosine by BulkSupplements.com label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
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)The Ingredients in L-Tyrosine by BulkSupplements.com
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size1000 mg Dosage formPowder Servings per container250 Amounts shown are per serving.
L-Tyrosine
Interacts with21 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 performan...
L-Tyrosine monograph & interactionsL-Tyrosine by BulkSupplements.com Drug Interactions
HelloPharmacist Interaction Report
L-Tyrosine by BulkSupplements.com does interact with certain medications, and there are two drug types you'll want to check before starting.
Read the full breakdown — every affected drug type, severity by severity
The most serious interaction is with levodopa (used for Parkinson's disease). Tyrosine and levodopa compete for the same absorption pathway in your small intestine, which means tyrosine might make levodopa less effective at treating your symptoms.
If you take levodopa, separate your tyrosine dose from it by at least 2 hours.
Tyrosine also has a moderate interaction with thyroid hormone medications. Because tyrosine is a building block for thyroid hormones, taking extra tyrosine might boost your thyroid hormone levels and add to the effect of your medication — something you'll want your doctor to monitor.
Altogether, these interactions span 21 individual medications. Use the medication checker below to look up your exact prescriptions before you start.
Check your own medications below · Editorial policy · How we use AI
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 checkerIngredients driving the most interactions
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
Benserazide, LevodopaMadopar, Prolopa
How Benserazide, Levodopa interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineLevodopa Moderate
Interaction Summary
Theoretically, tyrosine might decrease the effectiveness of levodopa.
Read the full L-tyrosine + Benserazide, Levodopa interactionCarbidopa, LevodopaDhivy, Rytary, Sinemet, Sinemet CR
How Carbidopa, Levodopa interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineLevodopa Moderate
Interaction Summary
Theoretically, tyrosine might decrease the effectiveness of levodopa.
Read the full L-tyrosine + Carbidopa, Levodopa interactionCarbidopa, Levodopa, EntacaponeStalevo
How Carbidopa, Levodopa, Entacapone interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineLevodopa Moderate
Interaction Summary
Theoretically, tyrosine might decrease the effectiveness of levodopa.
Read the full L-tyrosine + Carbidopa, Levodopa, Entacapone interactionConjugated EstrogensCenestin, Enjuvia, Premarin, Premarin Vaginal Cream
How Conjugated Estrogens interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Conjugated Estrogens interactionDesiccated Thyroid ExtractWesthroid, WP Thyroid
How Desiccated Thyroid Extract interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Desiccated Thyroid Extract interactionDesiccated Thyroid Extract (prescription Drug)Nature-Throid, Thyrar
How Desiccated Thyroid Extract (prescription Drug) interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Desiccated Thyroid Extract (prescription Drug) interactionDextrothyroxineCholoxin
How Dextrothyroxine interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Dextrothyroxine interactionHuman Chorionic Gonadotropin (hcg)Pregnyl
How Human Chorionic Gonadotropin (hcg) interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Human Chorionic Gonadotropin (hcg) interactionLevodopaInbrija, Larodopa
How Levodopa interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineLevodopa Moderate
Interaction Summary
Theoretically, tyrosine might decrease the effectiveness of levodopa.
Read the full L-tyrosine + Levodopa interactionLevodopa, CarbidopaDuodopa
How Levodopa, Carbidopa interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineLevodopa Moderate
Interaction Summary
Theoretically, tyrosine might decrease the effectiveness of levodopa.
Read the full L-tyrosine + Levodopa, Carbidopa interactionLevothyroxineEltroxin, Estre, Euthyrox, Levo-T, Levolet, Levothroid +5 more
How Levothyroxine interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Levothyroxine interactionLevothyroxine SodiumErmez, Thyquidity, Tirosint-Sol
How Levothyroxine Sodium interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Levothyroxine Sodium interactionLevothyroxine, LiothyronineArmour Thyroid
How Levothyroxine, Liothyronine interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Levothyroxine, Liothyronine interactionLiothyronineCytomel
How Liothyronine interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Liothyronine interactionLiotrixEuthroid 1, Euthroid 1/2, Euthroid 3
How Liotrix interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Liotrix interactionLiotrix, T4/t3Euthroid 2
How Liotrix, T4/t3 interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Liotrix, T4/t3 interactionMenotropinsMenopur, Repronex
How Menotropins interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Menotropins interactionOspemifeneOsphena
How Ospemifene interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Ospemifene interactionTestosterone UndecanoateAndriol, Aveed, Jatenzo, Kyzatrex
How Testosterone Undecanoate interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Testosterone Undecanoate interactionThyroglobulinProloid
How Thyroglobulin interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Thyroglobulin interactionThyroid HormoneEtwon
How Thyroid Hormone interacts with L-Tyrosine — through 1 ingredient. Tap an ingredient for the detail:
L-tyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full L-tyrosine + Thyroid Hormone interactionEach 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-Tyrosine
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.
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.
Brand information
Manufacturer and brand details for L-Tyrosine, from the product label.
BulkSupplements.com
See all BulkSupplements.com products- Name
- BulkSupplements.com
- Street Address
- 7511 Eastgate Rd
- City
- Henderson
- State
- NV
- ZipCode
- 89011
- Web Address
- BulkSupplements.com
L-Tyrosine by BulkSupplements.com: Common Questions
Does L-Tyrosine by BulkSupplements.com interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Will L-tyrosine help me focus better at work?
What's the most common side effect I should watch for?
Can I take this if I'm pregnant?
Is this supplement safe for everyone?
What is L-tyrosine used for in the body?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Tyrosine is safe with your meds?
Our pharmacists answer your medication & supplement questions — free.
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.
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.
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.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
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
- 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.
- DiPiro JT, Talbert RL, Yee GC, et al; eds. Pharmacotherapy: A pathophysiologic approach. 4th ed. Stamford, CT: Appleton & Lange, 1999.
- Wood DR, Reimherr FW, Wender PH. Amino acid precursors for the treatment of attention deficit disorder, residual type. Psychopharmacol Bull 1985;21:146-9.
- van Spronsen FJ, van Rijn M, Bekhof J. Phenylketonuria: tyrosine supplementation in phenylalanine-restricted diets. Am J Clin Nutr 2001;73:153-7. PubMed
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