Tyrosine is considered a non-essential amino acid, meaning that your body will stop producing sufficient amounts when you're under stress sick or lacking sleep. Supplementing with tyrosine prevents you from reaching mental and physical exhaustion by replenishing your catecholamine transmitters like dopamine, noradrenaline and adrenaline, allowing your body to increase focus and adjust to stress more effectively. Tyrosine may also be used as a non-stimulant (caffeine free) pre workout. These products have a strict internet policy -- please contact us for more information on prices and delivery.