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Updated: 2026-05-29 · v2.0 · Prof. G. Pkhakadze, MD, MPH, PhDCiteEditorial
📰Read the full L-Tyrosine evidence review on GMJ News →Complete clinical article, references and updates on news.gmj.ge. This page is the structured safety summary.
2
Conditional
L-Tyrosine
L-Tyrosine / NALT
Conditionally SafeModerateAmino Acids
RDA
Typical 500–2,000 mg
Target
N/A
Upper limit
No UL
Products
17
Dosage by population group — reference
🔗 Best with: L-Theanine, Rhodiola, Caffeine (Anhydrous)✅ USP Verified, NSF Certified for Sport, Informed Sport
⚠ Patient on MAOIs + tyrosine — hypertensive crisis risk [1]
⚠ Patient expecting cognitive boost while rested — tyrosine only works under catecholamine depletion (stress/sleep deprivation) [2]
⚠ NALT vs L-Tyrosine — L-Tyrosine is preferred [2]
⚠ PKU patient — tyrosine supplementation is medically necessary [1]
ℹ️ Not obtained from food. Obtained as part of dietary protein rather than tracked individually toward a daily target.
🔬 Lab interpreter
ℹ️ No validated blood test. There is no established laboratory test to assess status or guide dosing for this ingredient. Clinical response and symptoms are the practical guide.
⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
Tyrosine maintains cognition under acute stress (military-grade evidence) but does NOT enhance baseline cognition in rested individuals. Take on empty stomach. Do NOT combine with MAOIs (hypertensive crisis). NALT is paradoxically less effective than plain L-tyrosine. PKU patients need tyrosine medically [1] [2].
1 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: See guidance
Safe at dietary levels. No supplementation data [1].
👦 Pediatric: See guidance
PKU: tyrosine supplementation is medically necessary [1]. Otherwise no pediatric supplementation data.
🏃 Athletes: Standard dose
⚖️ Obesity: Standard dose
Fat-soluble compounds may require dose adjustment in obesity.
🩺 Renal: Consult specialist
Dose adjustment may be needed in renal impairment.
🌱 Vegan: Standard dose

How to take

🍽 Timing: Empty stomach, 30–60 min before stress/demand [2].
💊 With food: EMPTY stomach — BCAAs compete for LNAA transporter [2].
🚫 Avoid: MAOIs. Take separately from protein meals [1] [2].
2 Which form?
FormBioavailabilityVeganCost
['L-Tyrosine', 'common', 'Standard form. 500–2,000 mg. Used in military and stress research [2].']StandardCheck label
['N-Acetyl-L-Tyrosine (NALT)', '', 'Acetylated form. Better water solubility but lower bioavailability — paradoxically may be less effective [2].']StandardCheck label
3 Common questions
Is tyrosine a stimulant? ▼
No — it is a catecholamine precursor. It does not directly stimulate like caffeine. It supports dopamine/norepinephrine synthesis when demand is high (stress, sleep deprivation). In rested, non-stressed individuals, supplementation has minimal effect [2].
NALT vs L-Tyrosine? ▼
Despite better water solubility, NALT (N-Acetyl-L-Tyrosine) has lower bioconversion to tyrosine and may be less effective than standard L-tyrosine. L-Tyrosine is preferred [2].
Does tyrosine help ADHD? ▼
Some preliminary evidence, but it is NOT a substitute for standard ADHD treatment. Tyrosine depletion worsens ADHD symptoms, suggesting catecholamine involvement, but supplementation trials are insufficient [1].
When should I take tyrosine? ▼
On empty stomach, 30–60 min before the anticipated stress/cognitive demand. Other amino acids (especially BCAAs) compete for the same brain transporter [2].
4 Clinical evidence

Strong

Catecholamine precursor: well-established biochemistry [1]. US military research: tyrosine (150 mg/kg) maintained cognitive performance during 24-hour sleep deprivation and cold exposure in multiple studies [2]. HIGH

Moderate

Acute stress performance: consistent evidence from military/sleep deprivation trials [2]. ADHD: some evidence for modest benefit as adjunct [1]. Phenylketonuria: tyrosine supplementation is standard (can't convert Phe→Tyr) [1]. MODERATE

Insufficient

Baseline cognitive enhancement in non-stressed, well-rested individuals: no convincing benefit [2]. Depression: tyrosine alone does not treat depression [1]. Exercise performance: inconsistent [2]. LOW
5 Safety, toxicity & adverse events

Absolute contraindications

✕ Concurrent MAOIs — risk of hypertensive reaction

Relative

⚠ Hyperthyroidism or Graves' disease — precursor to thyroid hormone
⚠ Concurrent levodopa or thyroid medication — competes for absorption/effect
⚠ Melanoma — theoretical concern as a melanin precursor

🚩 Red flags

● Patient on MAOIs — hypertensive crisis risk [1]
6 Interactions

Drug interactions

MAOIs Major
Mechanism: Tyrosine → catecholamines + MAO inhibition = catecholamine accumulation. [1]
Effect: Hypertensive crisis. [1]
Action: CONTRAINDICATED with MAOIs [1].

Supplement synergies

L-Theanine + Caffeine · 200 mg theanine + 100 mg caffeine
The 'stress stack': tyrosine (catecholamine support) + theanine (calm) + caffeine (alertness) [2].
7 Regulatory
United States (FDA): GRAS. Dietary supplement [1].
Military use: Used in US/NATO military research for stress resilience [2].
8 US supplement products
17
on-market products containing L-Tyrosine (NIH DSLD)

Brands carrying L-Tyrosine (3)

Click a brand to see its L-Tyrosine products.
Or browse all 17 products in one list →
9 Frequently paired with
L-Phenylalanine 6 sharedL-Methionine 4 sharedL-Lysine 4 sharedIodine 4 sharedL-Leucine 4 shared
L-Tyrosine vs L-TheanineL-Tyrosine vs Rhodiola
10 Cite this page
Vancouver: Pkhakadze G. L-Tyrosine — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Jul 15]. Available from: https://supplement.ge/ingredients/l-tyrosine/
APA 7th: Pkhakadze, G. (2026). L-Tyrosine — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/l-tyrosine/
📋 Editorial information
Author: Prof. G. Pkhakadze, MD, MPH, PhD
Affiliation: David Tvildiani Medical University (DTMU)
First published: January 2026
Last reviewed: 2026-05-29
Next review: January 2027
References: 2 cited sources
COI: SupplementIndex receives no funding from supplement manufacturers. All content independently authored by PHIG.
Process: Systematic literature review
📄 License & reuse
Published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt for any purpose with attribution.
Pkhakadze G. "L-Tyrosine — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/l-tyrosine/ CC BY 4.0.
GP
Prof. G. Pkhakadze, MD, MPH, PhD
Professor of Public Health · Head of Department, DTMU
Editor-in-Chief, Georgian Medical Journal (ISSN 3088-4322)
Chair, Public Health Institute of Georgia · UEMS Public Health Section
Educational and public health purposes. CC BY 4.0. Consult your healthcare provider before starting any supplement. Corrections: info@accreditation.ge. Publisher: PHIG