L-Tyrosine 500 mg Ingredients & Drug Interactions
What is this page for?
First and foremost: checking 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
L-Tyrosine 500 mg is a dietary supplement by Doctor's Best 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 Tyrosine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against L-Tyrosine 500 mg by Doctor's Best
Ask about any prescription or over-the-counter medication and we check it for interactions with L-Tyrosine 500 mg by Doctor's Best — 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 500 mg by Doctor's Best
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: tyrosine, an amino acid your body uses to make several important compounds, including dopamine, norepinephrine, and thyroid hormones. Each capsule delivers 500 mg of tyrosine.
The capsule itself is made from hypromellose (a plant-based film), the only inactive ingredient.
Does it work?
Moderate evidence
Tyrosine is effective for phenylketonuria (PKU), a rare genetic condition. For cognitive function and memory, the evidence rates as possibly effective — meaning some research supports benefit, but more study is needed.
For athletic performance, the evidence suggests it's probably not effective. The data we hold isn't established enough to rate its use for alcohol use disorder or dementia.
How safe is it?
Well-documented data
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 thorough safety evaluation hasn't been done. We don't have enough safety data to recommend regular use without first talking to your healthcare provider, and there isn't enough data to know if it's safe while breastfeeding, so check with your doctor or pharmacist before starting it in either situation.
Meds to double-check
Moderate interaction found
Check with your doctor or pharmacist if you take levodopa (a Parkinson's medication) — tyrosine can reduce its absorption if you don't space them out by 2 hours or more. Also flag any thyroid hormone medication like levothyroxine, because tyrosine might boost thyroid hormone levels.
Use the search tool on this page to enter your exact medications.
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 might help with memory and thinking, and it's proven effective for PKU. If you take levodopa or thyroid medication, you'll want to double-check this with your doctor or pharmacist first — there's a moderate interaction with each.
Start the conversation with your healthcare provider if you're considering regular use, especially if you're pregnant, breastfeeding, or taking any prescription medication.
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 22, 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 500 mg, straight from the product label.
| Brand | Doctor's Best |
|---|---|
| Barcode (UPC) | 753950003163 |
| Net contents | 120 Veggie Cap(s) |
| Market status | On market |
| Date entered into DSLD | Feb 22, 2024 |
| DSLD ID | 302686 |
| 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 |
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 500 mg by Doctor's Best, sourced from the NIH Dietary Supplement Label Database.
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.
Formula
Tyrosine is a conditionally essential amino acid that is a precursor to the catecholamine transmitters dopamine, epinephrine, and norepinephrine. These are vital messengers for the brain and the body's other nerve networks. The thyroid gland also needs tyrosine to make the vital hormone thyroxine.
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.
Brand IP Statement(s)
Doctor's Best Science-Based Nutrition
Formulation
Brain Transmitter Support
Non-GMO / Gluten Free
Precursor for the nerve messengers dopamine, norepinephrine, and epinephrine (adrenaline) Precursor for thyroxine production by the thyroid gland.
FDA Statement of Identity
Dietary Supplement
Suggested/Recommended/Usage/Directions
Suggested Adult Use: Take 1 capsule daily between meals, or as recommended by a nutritionally informed physician.
Storage
Store in a cool dry place.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
L-Tyrosine 500 mg by Doctor's Best 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 500 mg by Doctor's Best
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size1 Veggie Capsule(s) Dosage formCapsule Servings per container120 Amounts shown are per serving.
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...
Tyrosine monograph & interactionsOther (inactive) ingredients: Hypromellose. These complete the product’s ingredient list but are not active constituents.
L-Tyrosine 500 mg by Doctor's Best Drug Interactions
HelloPharmacist Interaction Report
L-Tyrosine 500 mg by Doctor's Best interacts with two medication types: levodopa (a Parkinson's drug) and thyroid hormones.
The most serious concern is a moderate interaction with levodopa — tyrosine and levodopa compete for absorption in your small intestine, which can reduce how well the levodopa works. If you take levodopa, separate your tyrosine dose by at least 2 hours.
Read the full breakdown — every affected drug type, severity by severity
Tyrosine may also have additive effects with thyroid hormone medications (like levothyroxine). Because tyrosine is a building block for thyroid hormones, taking it alongside thyroid medication might increase your hormone levels.
Altogether, these interactions span 21 individual medications.
If you take levodopa, thyroid medication, or any other prescription, use the search tool below to check your exact drugs before you start this supplement.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against 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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in L-Tyrosine 500 mg interact with 21 drugs. Click any drug to see the details.
1 of the 1 ingredient in L-Tyrosine 500 mg interact with drugs. Each result below shows which ingredient is responsible. Tyrosine
Benserazide, LevodopaMadopar, Prolopa
How Benserazide, Levodopa interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineLevodopa Moderate
Interaction Summary
Theoretically, tyrosine might decrease the effectiveness of levodopa.
Read the full Tyrosine + Benserazide, Levodopa interactionCarbidopa, LevodopaDhivy, Rytary, Sinemet, Sinemet CR
How Carbidopa, Levodopa interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineLevodopa Moderate
Interaction Summary
Theoretically, tyrosine might decrease the effectiveness of levodopa.
Read the full Tyrosine + Carbidopa, Levodopa interactionCarbidopa, Levodopa, EntacaponeStalevo
How Carbidopa, Levodopa, Entacapone interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineLevodopa Moderate
Interaction Summary
Theoretically, tyrosine might decrease the effectiveness of levodopa.
Read the full Tyrosine + Carbidopa, Levodopa, Entacapone interactionConjugated EstrogensCenestin, Enjuvia, Premarin, Premarin Vaginal Cream
How Conjugated Estrogens interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Conjugated Estrogens interactionDesiccated Thyroid ExtractWesthroid, WP Thyroid
How Desiccated Thyroid Extract interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Desiccated Thyroid Extract interactionDesiccated Thyroid Extract (prescription Drug)Nature-Throid, Thyrar
How Desiccated Thyroid Extract (prescription Drug) interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Desiccated Thyroid Extract (prescription Drug) interactionDextrothyroxineCholoxin
How Dextrothyroxine interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Dextrothyroxine interactionHuman Chorionic Gonadotropin (hcg)Pregnyl
How Human Chorionic Gonadotropin (hcg) interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Human Chorionic Gonadotropin (hcg) interactionLevodopaInbrija, Larodopa
How Levodopa interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineLevodopa Moderate
Interaction Summary
Theoretically, tyrosine might decrease the effectiveness of levodopa.
Read the full Tyrosine + Levodopa interactionLevodopa, CarbidopaDuodopa
How Levodopa, Carbidopa interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineLevodopa Moderate
Interaction Summary
Theoretically, tyrosine might decrease the effectiveness of levodopa.
Read the full Tyrosine + Levodopa, Carbidopa interactionLevothyroxineEltroxin, Estre, Euthyrox, Levo-T, Levolet, Levothroid +5 more
How Levothyroxine interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Levothyroxine interactionLevothyroxine SodiumErmez, Thyquidity, Tirosint-Sol
How Levothyroxine Sodium interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Levothyroxine Sodium interactionLevothyroxine, LiothyronineArmour Thyroid
How Levothyroxine, Liothyronine interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Levothyroxine, Liothyronine interactionLiothyronineCytomel
How Liothyronine interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Liothyronine interactionLiotrixEuthroid 1, Euthroid 1/2, Euthroid 3
How Liotrix interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Liotrix interactionLiotrix, T4/t3Euthroid 2
How Liotrix, T4/t3 interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Liotrix, T4/t3 interactionMenotropinsMenopur, Repronex
How Menotropins interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Menotropins interactionOspemifeneOsphena
How Ospemifene interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Ospemifene interactionTestosterone UndecanoateAndriol, Aveed, Jatenzo, Kyzatrex
How Testosterone Undecanoate interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Testosterone Undecanoate interactionThyroglobulinProloid
How Thyroglobulin interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Thyroglobulin interactionThyroid HormoneEtwon
How Thyroid Hormone interacts with L-Tyrosine 500 mg — through 1 ingredient. Tap an ingredient for the detail:
TyrosineThyroid Hormone Moderate
Interaction Summary
Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Read the full Tyrosine + Thyroid Hormone interactionEach ingredient & the kinds of drugs it affects
For each ingredient in 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.
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 500 mg, from the product label.
Doctor's Best
See all Doctor's Best products- Name
- Doctor's Best, Inc.
- City
- Tustin
- State
- California
- ZipCode
- 92780
- Phone Number
- (800) 777-2474
- Web Address
- www.drbvitamins.com
L-Tyrosine 500 mg by Doctor's Best: Common Questions
Does L-Tyrosine 500 mg by Doctor's Best interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
What does tyrosine do in the body?
Is L-Tyrosine safe to take every day?
Can I take this while breastfeeding?
Will this help with my memory?
What are the most common side effects?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if L-Tyrosine 500 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 500 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 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.
- 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