Research topics described below are educational context, not a promise to diagnose, treat, cure, or prevent disease. Review the ingredient, suggested-use, warning, and interaction information before ordering, and ask a qualified healthcare professional if the product may not be appropriate for you.
Pre-orders are live. Your $100 USD payment creates a physical pre-order for this product and is applied to its final declared price. At $100 or less, we refund any unused amount automatically and ship when ready. Above $100, we email only for the balance.
Campaign milestone: 1,000 units for this product. Orders may continue beyond the milestone; it is a production target, not an inventory cap.
Free-form L-tyrosine, presented without daily-stimulant promises. Each capsule provides 500 mg of fermentation-derived L-tyrosine. Free-form L-tyrosine is the form used in most human research; that does not mean one capsule reproduces the much larger doses used in many acute-stress studies.
At a glance
| Active ingredient | L-tyrosine |
|---|---|
| Strength | 500 mg per capsule |
| Form and source | Free-form, fermentation-derived; specified to Ph. Eur./USP pharma-grade standards |
| Pack | 90 capsules |
| Pre-order payment | $100 USD, recorded on this physical product order and applied to the final declared price; automatic shipment at $100 or less; balance request only above $100 |
| Product milestone | 1,000 units; pre-orders can continue after the target is reached |
Sourcing and quality
The public specification is fermentation-derived, free-form L-tyrosine meeting Ph. Eur./USP pharma-grade standards. The finished production lot will be third-party tested and its lot-level Certificate of Analysis published before shipment. The final label and finished-lot COA are still pending, so excipients and other release details should be taken from those documents rather than assumed.
What the evidence does—and does not—say
Human evidence is moderate for preserving some cognitive performance during unusual acute stress, including sleep deprivation and cold exposure. Many positive studies used 100–150 mg/kg—far more than a single 500 mg capsule—and smaller doses have weaker or mixed support. Evidence does not justify claims for routine daily motivation, ADHD, depression, thyroid support, or reliable exercise improvement. This product is not presented as a treatment for any condition.
Side effects and interactions
Possible effects include nausea or other stomach upset, headache, heartburn, jitteriness, anxiety, irritability, insomnia, palpitations, or changes in blood pressure. Do not combine L-tyrosine with monoamine oxidase inhibitors (MAOIs). Obtain prescriber approval before use with levodopa or other Parkinson’s medicines, thyroid medicines, prescription stimulants, decongestants, psychiatric medicines, high-dose caffeine, or other catecholamine-raising products. Avoid unsupervised use with hyperthyroidism, uncontrolled hypertension, significant anxiety or mania risk, during pregnancy or breastfeeding, or in phenylketonuria care.
Safety notice: This is a dietary supplement, not a medicine. It is not intended to diagnose, treat, cure, or prevent disease. Do not start, stop, or change a prescribed medicine based on this page. Follow the final product label and consult a qualified healthcare professional when appropriate.
Read the full independent Pure City Research review of L-tyrosine →
