Tyrosine

Evidence Level: L5

Predicted Indications: 10

Tyrosine

Pharmacist Assessment Report

Tyrosine: From Unspecified Nutritional Use to Cauda Equina Syndrome

One-Sentence Summary

Tyrosine is an amino acid and a precursor of catecholamines and thyroid hormones. It is marketed in Australia in oral dietary-management products, but no approved indication text is available in the data compiled for this report. The TxGNN model predicts it may be effective for cauda equina syndrome, but there are 0 clinical trials and 0 publications supporting this prediction, so it rests on a model score alone.

Quick Overview

Item	Content
Original Indication	Not available in the data compiled for this report (no approved indication text recorded for the ARTG entries)
Predicted New Indication	Cauda equina syndrome
TxGNN Prediction Score	0.9977
Evidence Level	L5
Australia Market Status	Listed on the PBS Schedule (5 of 5 items) – TGA (ARTG) registration status is not included in this data
Number of PBS Items	5 (valid: 5)
Recommended Decision	Hold

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available. Based on known information, tyrosine is a proteinogenic amino acid and the starting substrate for catecholamine synthesis (L-DOPA, dopamine, noradrenaline) and for thyroid hormone synthesis.

Cauda equina syndrome is a compressive injury to the lumbosacral nerve roots, usually caused by disc herniation or other structural lesions, and is managed surgically. No plausible pathway links tyrosine supplementation to this condition. The high score (0.9977) comes from the TxGNN model (deep learning) and may reflect similarities the model learned between related diseases, not biological evidence. This report does not find it mechanistically credible.

The other top-ranked predictions show the same pattern:

Hyperthyroidism and hyperthyroxinemia: Tyrosine is a thyroid hormone precursor, so supplementation would be expected to be neutral or unfavourable, not beneficial.
Glaucoma subtypes (angle-closure, traumatic, neovascular, aqueous misdirection): These are largely anatomical or vascular disorders with no tyrosine link.
Resistance to thyroid hormone (THRB mutation): This is a receptor defect that a hormone precursor would not address.
Postural orthostatic tachycardia syndrome: There is a plausible indirect link via catecholamine synthesis, but the only publication is a case report using a tyrosine hydroxylase inhibitor, which acts in the opposite direction.

Clinical Trial Evidence

Currently no related clinical trials registered for cauda equina syndrome.

For context, one trial exists for the fourth-ranked prediction (hyperthyroidism):

Trial Number	Phase	Status	Enrolment	Key Findings
NCT06264544	Not applicable	Not yet recruiting	150	Placebo-controlled trial of a zinc, selenium and L-tyrosine supplement to prevent thyrotoxicosis in adults with elevated TPOAb and the SEPP1 r25191G/A polymorphism. Tyrosine is not the sole active component, and no efficacy data are available.

Literature Evidence

Currently no related literature available for cauda equina syndrome.

The literature retrieved for the other predictions is general and does not test tyrosine as an intervention:

PMID	Year	Type	Journal	Key Findings
36848916	2023	Review	Lancet Diabetes Endocrinol	General review of hyperthyroidism aetiology, diagnosis and management. No tyrosine-specific evidence.
42812246	2026	Cohort	Front Med	Plasma amino acid alterations in early primary angle-closure glaucoma. Associative biomarkers only, not evidence of therapeutic benefit.
39063020	2024	Case report	Int J Mol Sci	Chronic fatigue syndrome case responding to alpha-methyl-p-tyrosine, a tyrosine hydroxylase inhibitor. Opposite pharmacological direction, and not about POTS.
10579356	1999	Basic/genetic study	Endocrinology	THRB mutations at serine 314 impair ligand binding in thyroid hormone resistance. No tyrosine intervention.
35087972	2021	Review	Rom J Ophthalmol	Review of neovascular glaucoma aetiopathogenesis and treatment. No tyrosine link.

Note: several retrieved papers (for example PMID 24821006) concern tyrosine kinase inhibitors, which are a different drug class and unrelated to the amino acid.

Australia Market Information

ARTG Number	Product Name	Dosage Form	Approved Indication
ARTG 9165J	Tyrosine 1000	Oral powder sachets, 4 g (1 g tyrosine), 30	Not available
ARTG 12015J	TYR Easy Tablet	Tablets containing 0.91 g protein, 462	Not available
ARTG 10260B	TYR Anamix Junior	Oral powder sachets, 36 g, 30	Not available
ARTG 14126L	TYR explore5	Oral powder sachets, 12.5 g, 30	Not available
ARTG 10934L	TYR Easy Shake & Go	Oral powder bottle, 34 g, 30	Not available

All five entries are valid single-ingredient listings with oral routes of administration.

Safety Considerations

Please refer to the TGA-approved Product Information (PI) for safety information. No drug interaction records were found, and no knowledge-graph contraindications were identified.

Tyrosine is a thyroid hormone precursor, so use in people with hyperthyroidism or other thyroid disorders warrants clinical caution.

Conclusion and Next Steps

Decision: Hold

Rationale: The prediction for cauda equina syndrome is supported only by a TxGNN model (deep learning) score, with no clinical trials, no literature and no plausible mechanism. No other top-ranked prediction has supporting evidence either (all L4 to L5).

To proceed, the following is needed:

Mechanism of action data and a credible biological rationale linking tyrosine to the proposed indication
Approved indication text and Product Information (warnings and contraindications) for the ARTG entries
Preclinical or clinical evidence in the target condition before any further evaluation
Review of the top predictions for ontology artefacts (for example, the obsolete neurogenic bladder term) and for lexical false matches to tyrosine kinase inhibitors
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.