Doctor's Best L-Tyrosine 500mg 120 Veggie Caps provides a free-form, crystalline amino acid that serves as the direct precursor to the catecholamine neurotransmitters dopamine, norepinephrine, and epinephrine — the brain chemicals most associated with focus, motivation, mood, and the stress response. L-Tyrosine also serves as a precursor to thyroid hormones and the skin pigment melanin.*

• Direct precursor to dopamine, norepinephrine, and epinephrine*
• Supports mental focus, motivation, and cognitive performance*
• Supports healthy mood and stress resilience*
• Supports thyroid hormone synthesis*
• Free-form, crystalline amino acid for rapid absorption*
• Non-GMO | Gluten Free | Vegan | 120 veggie capsules

Suggested Use: As a dietary supplement, take 1–2 capsules daily on an empty stomach, or as directed by your healthcare professional.

Frequently Asked Questions

How does L-Tyrosine support focus and mental performance?

L-Tyrosine is the direct amino acid precursor for dopamine and norepinephrine — two catecholamine neurotransmitters central to attention, motivation, working memory, and executive function. Research shows L-Tyrosine supplementation is particularly effective at maintaining cognitive performance during periods of acute stress, sleep deprivation, cold exposure, and multitasking — situations where catecholamine depletion most commonly impairs mental function.*

Is L-Tyrosine the same as N-Acetyl L-Tyrosine (NALT)?

No. L-Tyrosine and N-Acetyl L-Tyrosine are different compounds. While NALT has better water solubility and was historically thought to be more bioavailable, research suggests the acetyl group may actually reduce conversion to active catecholamines. Free-form L-Tyrosine has demonstrated clear efficacy in multiple human studies and is generally considered the more reliable form for cognitive support.*

When is the best time to take L-Tyrosine?

L-Tyrosine is best taken on an empty stomach 30–60 minutes before the cognitive or physical demand you want to support — such as before work, study, or exercise. Taking it with protein-rich foods reduces absorption as amino acids compete for transport. Morning or pre-task dosing is typically most effective.*

Can L-Tyrosine support thyroid function?

Yes. Tyrosine is a precursor for thyroid hormones T3 and T4, which are formed by iodination of tyrosine residues in thyroglobulin. People with suboptimal thyroid function may benefit from ensuring adequate tyrosine intake alongside iodine and selenium. However, supplemental L-Tyrosine will not replace thyroid medication and should not be used to self-treat thyroid conditions without medical supervision.*