There are a number of limitations to the current science. These include:

• A diverse range of administration strategies (dose, form and source of the supplement) reported within the literature.^{14, 15}
• Lack of investigations in the use of TYR in elite athlete populations. In addition, performance tests rarely reflect elite sport competitive events.
• Limited data^{3, 23} exploring TYR pharmacokinetics in response to pharmacological grade supplementation, limited to dosages of 100 - 300 mg/kg body mass (300 mg/kg body mass dose administered via two equal dosages 4 hours apart).
• Many exercise or ‘stressor’ protocols within the current data may not be ‘stressful’ enough to deplete central catecholamines sufficiently, to surface TYR effects.
• Mechanistic approaches and thus data to quantitatively assess related blood/brain biochemistry changes (including TYR supplementation upon these) alongside advanced brain imaging techniques.
• Not all studies report plasma/serum measures of TYR.