L-Tyrosine 750 mg Ingredients & Drug Interactions
What is this page for?
First and foremost: checking L-Tyrosine 750 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
L-Tyrosine 750 mg is a dietary supplement by Natural Factors 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 750 mg by Natural Factors
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Tyrosine 750 mg by Natural Factors — 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 750 mg by Natural Factors
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 at 750 mg per capsule. Tyrosine is an amino acid your body uses to make several important compounds, including neurotransmitters that affect mood and focus, and thyroid hormones that regulate your metabolism.
The capsule itself is vegetarian, and the product also contains rice powder, magnesium stearate, and silica as inactive ingredients to help with capsule structure and flow.
Does it work?
Moderate evidence
The evidence for tyrosine varies by use. It's considered effective for phenylketonuria (PKU), a rare genetic condition where the body can't process the amino acid phenylalanine — tyrosine becomes essential in that case.
For cognitive function and memory, the evidence is only possibly effective, meaning some studies show promise but more research is needed. For athletic performance, the evidence currently leans toward it not being effective.
For alcohol use disorder and dementia, we don't have enough reliable evidence to know either way.
How safe is it?
Well-documented data
Orally, tyrosine is generally well tolerated in healthy adults. The most common side effects reported are fatigue, headache, heartburn, and nausea — especially at higher doses.
No serious adverse effects have been documented, though a comprehensive safety review hasn't been completed. Because safety data is limited, talk to your doctor or pharmacist before you start taking it regularly.
There isn't enough data to know if it's safe during pregnancy or while breastfeeding — your own healthcare provider can weigh the specific details of your situation.
Meds to double-check
Moderate interaction found
Before taking this product, double-check with your doctor or pharmacist if you take levodopa (a Parkinson's medication) or any thyroid hormone medication — both have documented Moderate interactions with tyrosine. Space levodopa doses at least 2 hours away from this supplement if your doctor approves both together.
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, and it's essential if you have PKU, but you'll want to check your medications first — especially if you take levodopa or thyroid hormones. It's generally well tolerated at this dose, though some people notice fatigue, headache, heartburn, or nausea.
Talk it over with your doctor or pharmacist before starting regular use, particularly if you're pregnant, breastfeeding, or taking any prescription medications.
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 Jul 25, 2018.
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 750 mg, straight from the product label.
| Brand | Natural Factors |
|---|---|
| Barcode (UPC) | 068958028125 |
| Net contents | 90 Vegetarian Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Jul 25, 2018 |
| DSLD ID | 179186 |
| Product type | Amino Acid/protein |
| Supplement form | Capsule |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Vegan, Vegetarian, Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar 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 750 mg by Natural Factors, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Tyrosine | 1500 mg | -- |
Other ingredients: Vegetarian Capsule, Rice powder, Magnesium Stearate, Silica
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.
Seals/Symbols
isura Non-GMO - Mass spec Documentation Lab tested
Suggested/Recommended/Usage/Directions
Suggested Usage: 2 capsules 2 times per day or as directed by a health professional.
Precautions
Cautions: As with any supplement, consult your health professional before use if you are pregnant, breastfeeding, or trying to conceive, or if you are taking medication, have a medical condition, or anticipate a surgery.
Keep out of the reach of children.
Sealed for your protection. Do not use if seal is broken.
General Statements
L-Tyrosine plays an important role in producing dopamine and noradrenaline, which are helpful for stress management. It helps transform fats into energy and promotes normal and healthy brain function including memory and concentration. It also supports normal muscle movement. Natural Factors amino acids are the highest quality pharmaceutical grade product available.
Manufactured by Natural Factors to ensure safety and potency in accordance with Good Manufacturing Practices (GMP) of the FDA and Health Canada.
Product of Canada
Purity & potency guaranteed
Recyclable container and label.
Free form amino acid
Stress management
Formulation
Contains no artificial colors, preservatives, or sweeteners; no dairy, sugar, wheat, gluten, yeast, soy, corn, egg, fish, shellfish, animal products, salt, tree nuts, or GMOs.
Suitable for vegetarians/vegans.
Storage
For freshness, store in cool, dry place.
FDA Disclaimer Statement
This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
FDA Statement of Identity
Dietary Supplement
General
R1
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Tyrosine 750 mg by Natural Factors 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 750 mg by Natural Factors
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size2 Vegetarian Capsule(s) Dosage formCapsule Servings per container45 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 & interactionsOther (inactive) ingredients: Vegetarian Capsule, Rice powder, Magnesium Stearate, Silica. These complete the product’s ingredient list but are not active constituents.
L-Tyrosine 750 mg by Natural Factors Drug Interactions
HelloPharmacist Interaction Report
Natural Factors L-Tyrosine 750 mg can interact with two important medication types.
The most serious concern is with levodopa (a Parkinson's medication) — tyrosine and levodopa both use the same absorption pathway in your small intestine, so tyrosine may reduce how well levodopa works. If you take levodopa, space your tyrosine dose at least 2 hours apart from it.
Read the full breakdown — every affected drug type, severity by severity
The other documented interaction is with thyroid hormone medications (like levothyroxine). Since tyrosine is a building block for thyroid hormones, taking it alongside your thyroid medication might amplify the effect.
This is also a Moderate concern.
Altogether, these interactions span 21 individual medications. Before you start this supplement, check your exact medications with the search tool on this page — especially if you take either levodopa or any thyroid hormone.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against L-Tyrosine 750 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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in L-Tyrosine 750 mg interact with 21 drugs. Click any drug to see the details.
1 of the 1 ingredient in L-Tyrosine 750 mg interact with drugs. Each result below shows which ingredient is responsible. L-Tyrosine
Benserazide, LevodopaMadopar, Prolopa
How Benserazide, Levodopa interacts with L-Tyrosine 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 mg — 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 750 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-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 750 mg, from the product label.
L-Tyrosine 750 mg by Natural Factors: Common Questions
Does L-Tyrosine 750 mg by Natural Factors interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
What is L-tyrosine used for?
Can I take this if I'm pregnant or breastfeeding?
What side effects might I notice?
Should I take this with or without food?
Is this the right dose for me?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Tyrosine 750 mg 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 750 mg’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 750 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.
- 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