Herb & supplement monograph

Tyrosine Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Tyrosine interacts with medications. The heart of this page is the interaction list — every drug Tyrosine is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Tyrosine is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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On this page

Interaction report

Drugs that interact with Tyrosine

21 medications have a known interaction with Tyrosine, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Tyrosine using our pharmacist-reviewed interaction data.

AI summaries are generated from our Tyrosine interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Tyrosine combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Tyrosine affects

Every type of medication (drug category) Tyrosine is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 2 drug categories Tyrosine interacts with

LevodopaThyroid Hormone

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

Monograph

Tyrosine: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

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, or cold, but the evidence is mixed and it is not proven for everyday focus or mood. It is generally well tolerated in healthy adults, but check with your pharmacist or doctor before using it, especially during pregnancy or if you have a thyroid condition.

Part used: Amino acid (made in the body or produced by fermentation/synthesis for supplements)
Common forms: Capsules, tablets, powder, and as L-tyrosine or N-acetyl-L-tyrosine

People commonly use it for

Mental focus and alertness
Coping with stress
Fatigue and sleep loss
Mood support
Athletic and cognitive performance

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Generally well tolerated in healthy adults, but talk to a healthcare provider before regular use.

PregnancyInsufficient reliable information

There is insufficient reliable information available about the safety of tyrosine during pregnancy and lactation when used in medicinal amounts. Some...

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

There is insufficient reliable information available about the safety of tyrosine during pregnancy and lactation when used in medicinal amounts. Some...

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Tyrosine (often sold as L-tyrosine) is an amino acid, which is one of the building blocks the body uses to make proteins. Your body can make it on its own from another amino acid called phenylalanine, so it is considered a "non-essential" amino acid. It is also found naturally in protein-rich foods like meat, fish, eggs, dairy, soy, nuts, and seeds.

As a supplement, tyrosine is usually made through fermentation or chemical processes and sold as a capsule, tablet, or powder. People most often take it hoping to improve mental focus, support mood, and help the body handle stressful situations. A modified form called N-acetyl-L-tyrosine is also sold, though it is not clearly better absorbed.

How it works

Tyrosine is a raw material your body uses to make several important brain and body chemicals, including the neurotransmitters dopamine, norepinephrine, and epinephrine (adrenaline). These chemicals play a role in alertness, focus, motivation, and the body's stress response.

The main idea behind supplementing is that during stress, your body may use up these neurotransmitters faster. Providing extra tyrosine may help the brain keep making them, which could help maintain mental performance under pressure. Tyrosine is also used to make thyroid hormones and the pigment melanin.

Much of this is based on biochemistry and small human studies. The way it affects everyday brain function in healthy people is not fully proven.

Effectiveness

Does Tyrosine work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 22 uses evaluated

1 Effective 2 Possibly effective 1 Leans ineffective 18 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

Effective Phenylketonuria (PKU)