The company focuses on vitamins, amino acids, plant extracts, sweeteners and other series of products, which have been widely used in food, health food, cosmetics, feed, veterinary medicine and other industries.
Products
High Purity L-Tryptophan Powder | ≥98% Feed, Food & Supplement Grade | CAS 73-22-3
Description:
Product Overview
L-Tryptophan is an essential aromatic amino acid that cannot be synthesized de novo by humans or monogastric animals, making it a critical nutrient that must be obtained through diet or supplementation. It serves as the sole biosynthetic precursor to serotonin (5-hydroxytryptamine) and melatonin, two neuroactive molecules that play fundamental roles in mood regulation, sleep architecture, appetite control, and circadian rhythm.
In animal nutrition, L-Tryptophan is recognized as the fourth limiting amino acid in swine and poultry diets, making it indispensable for optimizing growth performance, feed efficiency, and stress resilience. Recent research has also highlighted its significant role in immune function and intestinal health through its metabolites and their interactions with the aryl hydrocarbon receptor.
At Henan Liyin Biotech, we supply high-purity L-Tryptophan in the form of a white to light yellow crystalline powder, with a minimum purity of ≥98% , compliant with USP, EP, and FCC standards. Our product is available in Feed Grade, Food Grade, and Supplement Grade to serve applications across animal nutrition, human food, dietary supplements, and personal care.
Why Choose Our L-Tryptophan?
Verified Purity: Assay ≥98.0% (by HPLC), with typical batch results exceeding 99%, ensuring consistent potency for all applications
High Bioavailability: The natural L-form is the biologically functional isomer; D-Tryptophan exhibits only 21% relative nutritive value in poultry
Multi-Standard Compliance: Meets USP, EP, and FCC specifications, providing global regulatory acceptance
Complete Traceability: Each batch is accompanied by a comprehensive Certificate of Analysis (COA), including testing for purity, heavy metals, and microbiological contaminants
Flexible Packaging: Available in packaging options from 1kg to bulk quantities to suit your production needs
Key Functional Properties
Serotonin & Melatonin Precursor
L-Tryptophan is the only dietary compound that can be converted into serotonin (5-HT), a neurotransmitter that regulates mood, appetite, and sleep. Serotonin is subsequently converted into melatonin, the hormone responsible for the sleep-wake cycle. Studies have shown that tryptophan supplementation can decrease sleep latency, increase total sleep time, and reduce waking time.
Immune Function & Gut Health
L-Tryptophan exerts beneficial effects on the immune system through its metabolites, which activate the aryl hydrocarbon receptor expressed in various immune cells. Research has demonstrated that tryptophan supports antioxidant capacity, maintenance of mucosal integrity, modulation of microbiota composition, and promotion of intestinal health.
Stress Resilience & Mood Support
Clinical evidence suggests that in patients with depleted tryptophan diets, fortification with tryptophan led to significant improvement in depressive symptoms. Tryptophan helps balance mood by supporting serotonin production, with effects on the hypothalamic-pituitary-thyroid axis and other neuroendocrine pathways.
Growth Performance in Animals
As the fourth limiting amino acid in pig and poultry diets, L-Tryptophan plays a key role in growth performance and feed efficiency. Recent research in growing pigs demonstrated that higher SID Trp–Lys ratios (21–24%) optimized feed conversion and weight gain, particularly under immune challenge conditions.
Quality Assurance & Documentation
All batches undergo rigorous quality control, including:
Assay by HPLC: ≥98.0% (typical results 98.5–101.5%)
Heavy Metal Screening: Lead, arsenic, and other contaminants
Microbiological Testing: Salmonella negative (in 10g), coliforms negative
Specific Rotation and pH: Verified against USP/EP/FCC specifications
Loss on Drying and Residue on Ignition: To ensure stability
We provide complete documentation with every shipment, including Certificate of Analysis (COA), Material Safety Data Sheet (MSDS), and Allergen Statement. Our GMP-certified production ensures batch-to-batch consistency and traceability.
Sourcing Support
We offer flexible packaging and can provide samples for pre-shipment testing. Our technical team is available to assist with grade selection (Feed, Food, or Supplement Grade), application guidance, and custom formulation support — from R&D trials to full-scale commercial production.
Contact us to discuss your specific L-Tryptophan requirements or to request samples for your formulations.
Parameters:
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Parameter
Specification
Product Name
L-Tryptophan
CAS Number
73-22-3
Molecular Formula
C₁₁H₁₂N₂O₂
Molecular Weight
204.22 g/mol
Assay (Purity)
≥ 98.0% (by HPLC), typically 98.5–101.5% on dried basis
Appearance
White to light yellow crystalline powder
Available Grades
Feed Grade, Food Grade, Supplement Grade
Standards
USP, EP, FCC
Specific Rotation
[α]²⁰/D -29.0° to -32.8°
Loss on Drying
≤ 0.5%
Residue on Ignition
≤ 0.5%
Heavy Metals
≤ 10 ppm
Packaging Options
1kg, 5kg, 25kg (or as per request)
Documentation
Full COA, MSDS, Allergen Statement
Storage Conditions
Store in a cool, dry place, protected from light and moisture
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L-Tryptophan is an essential amino acid that serves as the sole precursor to serotonin and melatonin, supporting mood regulation, sleep quality, and circadian rhythm. In animal nutrition, it is the fourth limiting amino acid in swine and poultry diets, critical for growth performance, feed intake, and immune function. Available in Feed, Food, and Supplement Grades with ≥98% purity.
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Animal Feed
L-Tryptophan is an essential amino acid and the fourth limiting amino acid in pig and poultry diets, meaning it must be supplemented to achieve optimal growth performance and feed efficiency. Deficiency is characterized by decreased feed intake, poor growth rate, and reduced feed conversion.
Swine: Research has demonstrated that SID Trp–Lys ratios of 21% to 24% optimize growth performance in pigs from 16 to 33 kg, with the 24% ratio also modulating immune response under LPS-induced challenge conditions. This is higher than the NRC (16%) and some TBAS (18–19%) recommendations, suggesting that modern high-genetic-potential pigs may require higher tryptophan levels.
Poultry: For laying hens, L-tryptophan biomass 60% has been shown to be bioequivalent to L-tryptophan 98%, with a relative bioavailability value of 100%. Tryptophan supplementation supports egg production, feed efficiency, and stress resilience in poultry operations.
Recommended Inclusion: Levels vary by species and production stage. Typical feed grade product contains ≥98% L-Tryptophan, with the L-form providing significantly superior bioavailability compared to the D-isomer (21% relative nutritive value in poultry).
Dietary Supplements
L-Tryptophan is a popular ingredient in supplements targeting mood support, sleep quality, and overall wellness.
Sleep Support: Tryptophan supplementation has been shown to decrease sleep latency, increase total sleep time, and reduce waking time and number of awakenings. It is used safely and effectively to manage non-rapid eye movement (NREM) parasomnias in children where standard hypnotics are inappropriate.
Mood & Stress: L-Tryptophan supports serotonin production, which plays a key role in mood regulation. Evidence suggests that fortifying a depleted tryptophan diet can lead to significant improvement in depressive symptoms.
Cognitive Health: Serotonin and melatonin are of great importance for memory and learning, emotional regulation, and the circadian cycle, making tryptophan relevant for cognitive health formulations.
Typical Dosage: Doses of 1g or higher may help improve sleep quality by helping users stay asleep longer. Supplementation levels vary by intended use.
Food & Beverage
L-Tryptophan is used as a nutritional fortifier in food and beverage applications.
Food Fortification: Used to improve the amino acid profile of protein-based products and specialized nutrition formulations.
Functional Foods: Increasingly incorporated into functional beverages and health-focused food products targeting mood, sleep, and stress management.
Regulatory Status: FCC grade is suitable for food, beverage, and nutritional supplement applications.
Personal Care & Cosmetics
L-Tryptophan and its derivatives are used in personal care formulations for their skin-conditioning and antioxidant properties.
Skin Care: Supports skin health through its role in cellular metabolism and antioxidant protection.
Formula Compatibility: Stable in topical formulations and compatible with a wide range of cosmetic ingredients when stored in a cool, dry place protected from light.
Key words:
High Purity L-Tryptophan Powder | ≥98% Feed, Food & Supplement Grade | CAS 73-22-3
Function:
L-Tryptophan is an essential amino acid that serves as the sole precursor to serotonin and melatonin, supporting mood regulation, sleep quality, and circadian rhythm. In animal nutrition, it is the fourth limiting amino acid in swine and poultry diets, critical for growth performance, feed intake, and immune function. Available in Feed, Food, and Supplement Grades with ≥98% purity.
Application：
Animal Feed
L-Tryptophan is an essential amino acid and the fourth limiting amino acid in pig and poultry diets, meaning it must be supplemented to achieve optimal growth performance and feed efficiency. Deficiency is characterized by decreased feed intake, poor growth rate, and reduced feed conversion.
Swine: Research has demonstrated that SID Trp–Lys ratios of 21% to 24% optimize growth performance in pigs from 16 to 33 kg, with the 24% ratio also modulating immune response under LPS-induced challenge conditions. This is higher than the NRC (16%) and some TBAS (18–19%) recommendations, suggesting that modern high-genetic-potential pigs may require higher tryptophan levels.
Poultry: For laying hens, L-tryptophan biomass 60% has been shown to be bioequivalent to L-tryptophan 98%, with a relative bioavailability value of 100%. Tryptophan supplementation supports egg production, feed efficiency, and stress resilience in poultry operations.
Recommended Inclusion: Levels vary by species and production stage. Typical feed grade product contains ≥98% L-Tryptophan, with the L-form providing significantly superior bioavailability compared to the D-isomer (21% relative nutritive value in poultry).
Dietary Supplements
L-Tryptophan is a popular ingredient in supplements targeting mood support, sleep quality, and overall wellness.
Sleep Support: Tryptophan supplementation has been shown to decrease sleep latency, increase total sleep time, and reduce waking time and number of awakenings. It is used safely and effectively to manage non-rapid eye movement (NREM) parasomnias in children where standard hypnotics are inappropriate.
Mood & Stress: L-Tryptophan supports serotonin production, which plays a key role in mood regulation. Evidence suggests that fortifying a depleted tryptophan diet can lead to significant improvement in depressive symptoms.
Cognitive Health: Serotonin and melatonin are of great importance for memory and learning, emotional regulation, and the circadian cycle, making tryptophan relevant for cognitive health formulations.
Typical Dosage: Doses of 1g or higher may help improve sleep quality by helping users stay asleep longer. Supplementation levels vary by intended use.
Food & Beverage
L-Tryptophan is used as a nutritional fortifier in food and beverage applications.
Food Fortification: Used to improve the amino acid profile of protein-based products and specialized nutrition formulations.
Functional Foods: Increasingly incorporated into functional beverages and health-focused food products targeting mood, sleep, and stress management.
Regulatory Status: FCC grade is suitable for food, beverage, and nutritional supplement applications.
Personal Care & Cosmetics
L-Tryptophan and its derivatives are used in personal care formulations for their skin-conditioning and antioxidant properties.
Skin Care: Supports skin health through its role in cellular metabolism and antioxidant protection.
Formula Compatibility: Stable in topical formulations and compatible with a wide range of cosmetic ingredients when stored in a cool, dry place protected from light.
About Us
Henan Liyin Biotech Co.,Ltd
We are is established in 2024,located in Zhengzhou,on the banks of the Yellow River-the revered “Mother River “of China .As a specialized supplier of human nutrition and animal health products ,the company focuses on a range of products including vitamins ,amino acids ,plant extracts ,and sweeteners,which are widely used in industries ,such as food ,health supplements,cosmetics ,feed and veterinary medicine .By integrating global product resources with the needs of international clients ,Liyin Biotech provides premium products and professional services tailored to each customer .
FAQ
How to contact ?
You can contact with us by Whatsapp:+86 15824830539, the Average Response Time is 0-4h on Work time, <24h on Non-worktime.
For every inquiry, our sales will provide the one-for-one service for you.
How about the payment terms ?
Normal orders: Company account ;Sample/small orders: Paypal(The 5-10% extrafee).About the payment term, we will negotiate alone.
How to get the samples ?
At the first time ,we can provide you the normal product <30g free sample
How to confirm the Product Quality before placing orders?
1st, you can get free samples for some products, just paythe basic cost for us.
2nd,Also you can send the specification or your quest tous, we will customize the products for you.3rd,We emphasis that our whole company make a livingwith organic chemical and customers, we absolutelyimpossible to sale any fake goods, unqualified goods, it isshame! And None False certificate/lie/illegal thing in oursales net!
Which kind of payment do you accept?
- As usually we use company account ,T/T in advance ,or at least 30% T/T in advance ,the balance can be paid by the copy of B/L
- For some countrys we can accept L/C at sight & DP at sight
- For smaples we can use Paypal (The 5-10% extra fees) or other ways
About the payment term, we will negotiate alone.
How about the shipment ?
1>For bulk goods ,we can use contaioner by sea ,1&20 and 1&40 contaioner
2>For urgently and expensive goods ,we can arrange the air lines for customers choose ,or can as customer required
3>For samples or small quantity goods ,we can use Fedex or other express ways
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