Q1. What is L-tyrosine used for in dietary supplements?

L-Tyrosine is used primarily in cognitive performance, mental focus, mood support, stress response and thyroid-support products. As the precursor of dopamine, norepinephrine and thyroid hormones, it supports alertness, motivation and the body's adaptive response to demanding conditions. Purecium supplies L-tyrosine as a 99% minimum USP/EP/FCC-grade crystalline powder produced by non-GMO fermentation, plus N-Acetyl-L-Tyrosine for water-soluble formats, for distributors, contract manufacturers, private-label producers and supplement brands.

Q2. How does L-tyrosine support cognitive performance and stress response?

Under cognitively demanding or stressful conditions, the synthesis of dopamine and norepinephrine can outpace available substrate. L-Tyrosine provides the amino-acid precursor needed to maintain catecholamine levels, supporting focus, working memory and resilience during demanding tasks. Published clinical studies suggest benefits under high-load or stressful conditions, and the catecholamine pathway is a recognized topic in the health information resources of the NIH Office of Dietary Supplements.

Q3. What is the difference between L-tyrosine and N-Acetyl-L-Tyrosine?

L-Tyrosine is the free amino acid (CAS 60-18-4), while N-Acetyl-L-Tyrosine (NAT, CAS 537-55-3) is the acetylated derivative with significantly higher water solubility. NAT dissolves faster and is preferred for ready-to-mix powders, sticks and liquid concentrates, while free-form L-tyrosine is the standard choice for capsules and tablets. Both are viable nootropic precursors; the choice depends on the finished-product format and dissolution requirements.

Q4. What dose of L-tyrosine is commonly used in cognitive and stress products?

Cognitive and stress-support products commonly provide 500 mg to 2 g of L-tyrosine per serving, typically taken before demanding activities or during stressful periods, sometimes divided across the day. Doses at the higher end are more common in acute stress or high-performance scenarios. Formulators should set label strength according to destination-market regulations and the finished-product positioning.

Q5. What assay and quality specifications should I expect for L-tyrosine?

A high-purity L-tyrosine should be assayed at 99.0% minimum on a dried basis against the USP-NF or EP monograph, with identification, specific optical rotation within the pharmacopeial range confirming the L-enantiomer, related substances controlled by HPLC, heavy metals within limits, conforming residual solvents and microbial counts within USP/EP limits. Purecium reports all of these on the batch Certificate of Analysis, including the assay method, production date and expiry date.

Q6. Is L-tyrosine safe for use in dietary supplements?

Yes. L-Tyrosine is recognized as GRAS by the FDA in the United States, is covered by USP-NF and European Pharmacopoeia monographs, and EFSA has assessed amino acids including tyrosine for use in food supplements. It is a normal dietary amino acid present in protein foods and is well tolerated at typical supplement servings. As with any ingredient, formulators should confirm destination-market practice for dosage and claim wording.

Q7. Why is enantiomeric purity important for L-tyrosine?

Only the L-enantiomer of tyrosine is used in human nutrition and metabolism; the D-form is not a substrate for catecholamine synthesis and is not appropriate for food supplements. Fermentation production inherently yields the L-enantiomer, and specific optical rotation measured against the pharmacopeial value confirms it on every batch. Buyers should always request the specific rotation result on the CoA and confirm the method.

Q8. Can L-tyrosine be combined with caffeine, L-theanine or B vitamins?

Yes. L-Tyrosine is commonly paired with caffeine in pre-workout and focus products, with L-theanine for balanced cognitive support, and with B vitamins that participate in neurotransmitter metabolism. These combinations are standard in the nootropic category and show no known negative interactions at label doses. Formulators should verify ingredient compatibility, particle-size matching and blend uniformity, and confirm label claims comply with destination-market regulations.

Q9. Is L-tyrosine vegan?

Yes. Purecium's L-tyrosine is manufactured by microbial fermentation from non-GMO plant-based sugars, and N-Acetyl-L-Tyrosine is derived from the same fermentation-based L-tyrosine, with no animal-derived starting materials. Both carry a clear vegan, non-GMO, allergen-free and gluten-free statement and are suitable for vegan and vegetarian formulations.

Q10. What quality documentation should I request when sourcing L-tyrosine?

A professional supplier should provide a current specification sheet, a batch-specific Certificate of Analysis showing identification, assay (99.0% minimum), specific optical rotation, related substances by HPLC, heavy metals, residual solvents and microbial results, an SDS, allergen and gluten statements, and non-GMO declarations. Also request Kosher and Halal certificates, copies of the ISO 9001 and FSSC 22000 certificates, and stability data for registration purposes. Purecium provides this full documentation set on request for every shipment.

Q11. What is the MOQ and lead time for L-tyrosine from Purecium?

The minimum order quantity is 25 kg for either form. Both powders are packed in 25 kg drums with food-grade aluminum-foil inner bags, and samples and technical documentation are available before you commit. Standard production lead time is typically 7 to 15 working days after order confirmation, with faster dispatch for stocked items. For North American customers, Purecium holds inventory at its US warehouse, enabling pickup or delivery within approximately two days. Export documentation is prepared for every shipment.

Q12. How is the L-enantiomeric purity of L-tyrosine verified?

Enantiomeric purity is verified primarily by specific optical rotation measured against the pharmacopeial monograph value for L-tyrosine, and confirmed by chiral HPLC when required. The L-enantiomer rotates plane-polarized light within a defined range that distinguishes it from the D-form and racemic mixtures. Fermentation production inherently yields the L-enantiomer, and every Purecium batch reports the specific rotation result on the CoA.

Q13. Why does tyrosine matter for thyroid-support formulas?

L-Tyrosine is a required substrate for the synthesis of the thyroid hormones triiodothyronine (T3) and thyroxine (T4), which regulate metabolic rate and energy metabolism. Thyroid-support formulas therefore commonly combine L-tyrosine with iodine and selenium, which are also required for thyroid-hormone synthesis. This nutritional role is separate from tyrosine's neurotransmitter function and is well documented in nutritional science.

Q14. How should L-tyrosine be stored, and what is the shelf life?

Store L-tyrosine and N-Acetyl-L-Tyrosine in tightly sealed original containers in a cool, dry place below 25 degrees Celsius, protected from light and moisture. Both are stable crystalline powders under these conditions, and shelf life is generally 36 months from the date of manufacture. Each shipment's CoA states the production date and expiry date for inventory planning.

Q15. Why should we source L-tyrosine from Purecium?

Purecium supplies L-Tyrosine as a B2B raw material standardized to 99.0% minimum assay and produced to USP, EP and FCC standards via non-GMO fermentation, with specific optical rotation confirming L-enantiomeric purity on every batch, plus N-Acetyl-L-Tyrosine for water-soluble formats. Every batch is released with a full Certificate of Analysis including related-substances testing by HPLC, an SDS and supporting documentation. The minimum order is 25 kg, inventory is staged at our US warehouse for two-day pickup, and global delivery covers Hong Kong, mainland China, the EU and beyond. For long-term supply relationships, Purecium provides consistent quality, batch traceability, regulatory documents and direct technical communication rather than one-off spot pricing.

Bulk L-Tyrosine Powder USP/EP/FCC 99% Fermentation

L-Tyrosine Powder for Cognitive Performance and Stress Support Formulas
Fermentation-Derived USP/EP/FCC 99% with Verified Enantiomeric Purity
Embodies the essence of pure, high-quality dietary supplement ingredients
L-Tyrosine (Amino Acid, with N-Acetyl Form)
Cognitive Performance and Stress Support

L-Tyrosine
Purecium L-Tyrosine is a white, free-flowing crystalline powder for cognitive performance, mental focus, mood support and stress-response formulations. L-Tyrosine is the non-essential amino acid precursor of dopamine, norepinephrine and thyroid hormones, identified by CAS number 60-18-4 with molecular formula C9H11NO3 and molecular weight 181.19 g/mol. Our L-tyrosine is manufactured by non-GMO microbial fermentation to USP, EP and FCC standards with a 99.0% minimum assay, verified on every batch. We also supply N-Acetyl-L-Tyrosine (CAS 537-55-3, C11H13NO4, 223.22 g/mol), a more water-soluble derivative for ready-to-mix and liquid formats. Allergen-free, gluten-free, non-GMO and vegan, both forms are packed in 25 kg drums with a 25 kg minimum order for B2B buyers worldwide.

Product name: L-Tyrosine (Amino Acid) / N-Acetyl-L-Tyrosine
Molecular formula: C₉H₁₁NO₃ (L-Tyr) / C₁₁H₁₃NO₄ (NAT)
Starting material: Microbial fermentation (non-GMO plant-based substrate)
Grade: USP / EP / FCC
Heavy Metals: Conforms to USP/EP
Pesticide residue: Conforms to USP/EP
Packing size: 25kg/drum
CAS#: 60-18-4 (L-Tyr) / 537-55-3 (NAT)
Molecular weight: 181.19 g/mol (L-Tyr) / 223.22 g/mol (NAT)
Source: Fermentation (L-enantiomer)
Specification: 99.0% min assay (USP), white crystalline powder
Country of origin: China
Residual solvent: Conforms to USP/EP
Allergen free/Gluten-free/Non-GMO/Vegan/Non-Irradiation:

L-Tyrosine Overview

L-Tyrosine is a non-essential amino acid and the metabolic precursor of the catecholamine neurotransmitters dopamine and norepinephrine, as well as of thyroid hormones, making it a core ingredient in cognitive performance, mental focus, mood and stress-support supplements. It is identified by CAS number 60-18-4, molecular formula C9H11NO3 and molecular weight 181.19 g/mol. Under demanding conditions, supplemental tyrosine supports the maintenance of catecholamine levels, which is the basis of its role in cognitive resilience.

For the dietary supplement industry, L-tyrosine is used in cognitive performance, focus and attention, stress response, mood support, thyroid support and sports-adjacent mental-performance products. Purecium supplies L-tyrosine as a white crystalline powder standardized to 99.0% minimum assay, produced by microbial fermentation, together with N-Acetyl-L-Tyrosine for enhanced solubility, sold exclusively as B2B raw materials for distributors, contract manufacturers, private-label producers and finished supplement brands.

Source & Ingredient Identity

Purecium L-Tyrosine is manufactured by microbial fermentation, in which selected microbial strains convert non-GMO plant-based sugars into the L-enantiomer under controlled fermentation conditions, followed by purification by crystallization. The fermentation process inherently produces the natural L-enantiomer, the only form used in human nutrition, and it is the dominant commercial route for food-grade L-tyrosine.

The product is standardized to 99.0% minimum assay and conforms to USP-NF, European Pharmacopoeia and FCC monographs as applicable, produced in China and non-irradiated, with no allergens, no gluten and no GMO material. The N-Acetyl-L-Tyrosine derivative (CAS 537-55-3) is supplied as a white to off-white powder with improved water solubility for ready-to-mix and liquid formats. For B2B buyers, the critical purchasing checks are the assay on the Certificate of Analysis, specific optical rotation confirming the L-enantiomer, and the impurity profile by HPLC.

Key Characteristics of L-Tyrosine

1. Catecholamine precursor. L-Tyrosine is converted to L-DOPA, then to dopamine and norepinephrine, the neurotransmitters that support alertness, motivation, focus and the body's adaptive response to stress; the pathway is a recognized topic in the health information of the NIH Office of Dietary Supplements, and published clinical studies report benefits of tyrosine under cognitively demanding or stressful conditions.

2. Thyroid hormone building block. L-Tyrosine is a required substrate for the synthesis of the thyroid hormones T3 and T4, which regulate metabolic rate and energy metabolism, making it a common component of thyroid-support formulas alongside iodine and selenium.

3. Two sourcing forms for different formats. L-Tyrosine provides the free amino acid with standard crystalline handling, while N-Acetyl-L-Tyrosine offers higher water solubility and is preferred for ready-to-mix powders, sticks and liquid concentrates where dissolution speed matters. Both forms are manufactured to the same quality standards and are covered by appropriate monographs and regulatory assessments.

L-Tyrosine Manufacturing

The manufacturing process follows a fermentation route: selected microbial strains convert non-GMO plant-based sugars into L-tyrosine under controlled fermentation conditions, after which the broth is filtered, purified by ion exchange and crystallization, and dried to a white crystalline powder. Every production stage is process-controlled, and each finished lot is verified before release.

Each batch is tested by the methods of the current USP-NF or European Pharmacopoeia monograph for tyrosine, including identification, assay (99.0% minimum on a dried basis), specific optical rotation confirming the L-enantiomer, related substances by HPLC, heavy metals, residual solvents and microbial limits, all reported on the batch Certificate of Analysis. The N-Acetyl-L-Tyrosine derivative is produced by controlled acetylation of high-purity L-tyrosine followed by crystallization, with its own identity and assay verification per batch.

Applications of L-Tyrosine

Cognitive performance and stress support is the primary application of L-tyrosine. Mechanistically, under cognitively demanding or stressful conditions, catecholamine synthesis can outpace supply, and supplemental tyrosine provides the substrate needed to maintain dopamine and norepinephrine levels; published clinical studies suggest benefits for focus, working memory and resilience during demanding tasks, with typical servings of 500 mg to 2 g before or during demanding periods.

Mood, thyroid and sports-adjacent applications form the second cluster. As a precursor of dopamine and thyroid hormones, L-tyrosine is used in mood-support and thyroid-support formulas, and in pre-workout and sports-performance products for mental focus and motivation. The FDA recognizes L-tyrosine as GRAS for food use, and EFSA has assessed amino acids including tyrosine for use in food supplements; finished-product claims should always follow the regulations of the destination market.

L-Tyrosine is compatible with capsules, tablets, sachets and powder blends. The crystalline powder has a neutral taste and good flow, while N-Acetyl-L-Tyrosine is the preferred form for ready-to-mix and liquid applications. It is commonly paired with caffeine, B vitamins, L-theanine and other nootropic ingredients; formulators should protect both forms from light and moisture during blending and storage.

Manufacturing & Quality Control

Purecium L-Tyrosine and N-Acetyl-L-Tyrosine are produced in facilities operating under ISO 9001 and FSSC 22000 certified quality systems, with Kosher and Halal certification available. Analytical methods follow the current USP-NF and European Pharmacopoeia monographs for tyrosine, and each batch is released with a verified assay of 99.0% minimum on a dried basis.

Each commercial lot is fully traceable from fermentation culture to finished drum. Alongside the CoA, Purecium provides the specification sheet, SDS, allergen and gluten statements, non-GMO declarations and stability data on request, giving buyers the documentation needed for raw-material approval and finished-product registration.

L-Tyrosine for B2B Supplement Manufacturing

Purecium supplies L-Tyrosine and N-Acetyl-L-Tyrosine exclusively as B2B raw materials for distributors, contract manufacturers, private-label producers and finished supplement brands. The minimum order quantity is 25 kg; both forms are packed in 25 kg drums with food-grade aluminum-foil inner bags, and samples and full documentation are available before commitment.

For North American customers, inventory is staged at Purecium's US warehouse, enabling pickup or delivery within approximately two days. Global delivery covers Hong Kong, mainland China, the EU and other regions, with export documentation prepared for every shipment. Purecium also supports custom mesh sizing and provides technical and regulatory communication to move L-tyrosine from ingredient selection to commercial formulation.

Reviewed by the Chief Quality Assurance / Regulatory Affairs Specialist at Purecium for technical accuracy and regulatory alignment.
L-Tyrosine Frequently Asked Questions (FAQ) for B2B Buyers

Q1. What is L-tyrosine used for in dietary supplements?
L-Tyrosine is used primarily in cognitive performance, mental focus, mood support, stress response and thyroid-support products. As the precursor of dopamine, norepinephrine and thyroid hormones, it supports alertness, motivation and the body's adaptive response to demanding conditions. Purecium supplies L-tyrosine as a 99% minimum USP/EP/FCC-grade crystalline powder produced by non-GMO fermentation, plus N-Acetyl-L-Tyrosine for water-soluble formats, for distributors, contract manufacturers, private-label producers and supplement brands.
Q2. How does L-tyrosine support cognitive performance and stress response?
Under cognitively demanding or stressful conditions, the synthesis of dopamine and norepinephrine can outpace available substrate. L-Tyrosine provides the amino-acid precursor needed to maintain catecholamine levels, supporting focus, working memory and resilience during demanding tasks. Published clinical studies suggest benefits under high-load or stressful conditions, and the catecholamine pathway is a recognized topic in the health information resources of the NIH Office of Dietary Supplements.
Q3. What is the difference between L-tyrosine and N-Acetyl-L-Tyrosine?
L-Tyrosine is the free amino acid (CAS 60-18-4), while N-Acetyl-L-Tyrosine (NAT, CAS 537-55-3) is the acetylated derivative with significantly higher water solubility. NAT dissolves faster and is preferred for ready-to-mix powders, sticks and liquid concentrates, while free-form L-tyrosine is the standard choice for capsules and tablets. Both are viable nootropic precursors; the choice depends on the finished-product format and dissolution requirements.
Q4. What dose of L-tyrosine is commonly used in cognitive and stress products?
Cognitive and stress-support products commonly provide 500 mg to 2 g of L-tyrosine per serving, typically taken before demanding activities or during stressful periods, sometimes divided across the day. Doses at the higher end are more common in acute stress or high-performance scenarios. Formulators should set label strength according to destination-market regulations and the finished-product positioning.
Q5. What assay and quality specifications should I expect for L-tyrosine?
A high-purity L-tyrosine should be assayed at 99.0% minimum on a dried basis against the USP-NF or EP monograph, with identification, specific optical rotation within the pharmacopeial range confirming the L-enantiomer, related substances controlled by HPLC, heavy metals within limits, conforming residual solvents and microbial counts within USP/EP limits. Purecium reports all of these on the batch Certificate of Analysis, including the assay method, production date and expiry date.
Q6. Is L-tyrosine safe for use in dietary supplements?
Yes. L-Tyrosine is recognized as GRAS by the FDA in the United States, is covered by USP-NF and European Pharmacopoeia monographs, and EFSA has assessed amino acids including tyrosine for use in food supplements. It is a normal dietary amino acid present in protein foods and is well tolerated at typical supplement servings. As with any ingredient, formulators should confirm destination-market practice for dosage and claim wording.
Q7. Why is enantiomeric purity important for L-tyrosine?
Only the L-enantiomer of tyrosine is used in human nutrition and metabolism; the D-form is not a substrate for catecholamine synthesis and is not appropriate for food supplements. Fermentation production inherently yields the L-enantiomer, and specific optical rotation measured against the pharmacopeial value confirms it on every batch. Buyers should always request the specific rotation result on the CoA and confirm the method.
Q8. Can L-tyrosine be combined with caffeine, L-theanine or B vitamins?
Yes. L-Tyrosine is commonly paired with caffeine in pre-workout and focus products, with L-theanine for balanced cognitive support, and with B vitamins that participate in neurotransmitter metabolism. These combinations are standard in the nootropic category and show no known negative interactions at label doses. Formulators should verify ingredient compatibility, particle-size matching and blend uniformity, and confirm label claims comply with destination-market regulations.
Q9. Is L-tyrosine vegan?
Yes. Purecium's L-tyrosine is manufactured by microbial fermentation from non-GMO plant-based sugars, and N-Acetyl-L-Tyrosine is derived from the same fermentation-based L-tyrosine, with no animal-derived starting materials. Both carry a clear vegan, non-GMO, allergen-free and gluten-free statement and are suitable for vegan and vegetarian formulations.
Q10. What quality documentation should I request when sourcing L-tyrosine?
A professional supplier should provide a current specification sheet, a batch-specific Certificate of Analysis showing identification, assay (99.0% minimum), specific optical rotation, related substances by HPLC, heavy metals, residual solvents and microbial results, an SDS, allergen and gluten statements, and non-GMO declarations. Also request Kosher and Halal certificates, copies of the ISO 9001 and FSSC 22000 certificates, and stability data for registration purposes. Purecium provides this full documentation set on request for every shipment.
Q11. What is the MOQ and lead time for L-tyrosine from Purecium?
The minimum order quantity is 25 kg for either form. Both powders are packed in 25 kg drums with food-grade aluminum-foil inner bags, and samples and technical documentation are available before you commit. Standard production lead time is typically 7 to 15 working days after order confirmation, with faster dispatch for stocked items. For North American customers, Purecium holds inventory at its US warehouse, enabling pickup or delivery within approximately two days. Export documentation is prepared for every shipment.
Q12. How is the L-enantiomeric purity of L-tyrosine verified?
Enantiomeric purity is verified primarily by specific optical rotation measured against the pharmacopeial monograph value for L-tyrosine, and confirmed by chiral HPLC when required. The L-enantiomer rotates plane-polarized light within a defined range that distinguishes it from the D-form and racemic mixtures. Fermentation production inherently yields the L-enantiomer, and every Purecium batch reports the specific rotation result on the CoA.
Q13. Why does tyrosine matter for thyroid-support formulas?
L-Tyrosine is a required substrate for the synthesis of the thyroid hormones triiodothyronine (T3) and thyroxine (T4), which regulate metabolic rate and energy metabolism. Thyroid-support formulas therefore commonly combine L-tyrosine with iodine and selenium, which are also required for thyroid-hormone synthesis. This nutritional role is separate from tyrosine's neurotransmitter function and is well documented in nutritional science.
Q14. How should L-tyrosine be stored, and what is the shelf life?
Store L-tyrosine and N-Acetyl-L-Tyrosine in tightly sealed original containers in a cool, dry place below 25 degrees Celsius, protected from light and moisture. Both are stable crystalline powders under these conditions, and shelf life is generally 36 months from the date of manufacture. Each shipment's CoA states the production date and expiry date for inventory planning.
Q15. Why should we source L-tyrosine from Purecium?
Purecium supplies L-Tyrosine as a B2B raw material standardized to 99.0% minimum assay and produced to USP, EP and FCC standards via non-GMO fermentation, with specific optical rotation confirming L-enantiomeric purity on every batch, plus N-Acetyl-L-Tyrosine for water-soluble formats. Every batch is released with a full Certificate of Analysis including related-substances testing by HPLC, an SDS and supporting documentation. The minimum order is 25 kg, inventory is staged at our US warehouse for two-day pickup, and global delivery covers Hong Kong, mainland China, the EU and beyond. For long-term supply relationships, Purecium provides consistent quality, batch traceability, regulatory documents and direct technical communication rather than one-off spot pricing.
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