Tryptophan
Tryptophan is an essential amino acid that serves as a precursor to serotonin, a neurotransmitter involved in mood regulation and sleep. It is available by prescription in some countries for the treatment of depression and sleep disorders, and as a dietary supplement in others.
Tryptophan is an amino acid supplement used primarily for mood and sleep support that works by increasing serotonin production in the brain.
Key facts at a glance
- ATC
- N06AX02
- RxNorm
- 10898
- Generic
- Tryptophan
- Class
- atc-n06
- Brands
- Freamine III 10, Clinimix E 4.25/10, Restone, Aminosyn II 8.5 % with Electrolytes, Sulfite-Free, Aminosyn 8.5 % with Electrolytes, Sulfite-Free, Trophamine 10 %, Trophamine 6 %, Somnicin, Plenamine, Prosol, PremaSol, Aminosyn II 15%, Aminosyn II 8.5 %, Sulfite-Free, Aminosyn II 10 %, Aminosyn-HBC 7 %, Sulfite-Free
- Availability
- otc
- Pregnancy
- C
- Lactation
- caution
- Half-life (h)
- 2
- Onset (min)
- 45
- Duration (h)
- 6
- Routes
- oral, intravenous
- Forms
- capsule, tablet, oral powder, intravenous solution
- Regions
- United States, Canada, United Kingdom, Germany, France, Australia, Japan
- Monitoring
- liver function tests, renal function, electrolyte levels, serotonin-related symptoms
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 500mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 250mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 400mg daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
11 groupspregnancy
first trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring
Use with caution and monitor for adverse effects.
pregnancy
second trimesteruse lowest effective dose
continue only if parenteral nutrition is medically necessary
regular fetal monitoring and maternal assessment
Use with caution and monitor for adverse effects.
pregnancy
third trimesteruse lowest effective dose
continue only if parenteral nutrition is medically necessary
regular fetal monitoring and maternal assessment
Use with caution and monitor for adverse effects.
lactation
breastfeedingno adjustment needed
generally considered safe for breastfeeding mothers requiring parenteral nutrition
standard maternal monitoring
pediatric_age
neonatesuse pediatric-specific formulations
use Trophamine 6% or 10% designed for neonates and infants
close monitoring of amino acid levels and growth parameters
Use with caution and monitor for adverse effects.
pediatric_age
infantsuse pediatric-specific formulations
use Trophamine formulations designed for pediatric patients
monitor growth parameters and amino acid levels
Use with caution and monitor for adverse effects.
geriatric
elderlyno specific adjustment needed
generally well tolerated in elderly patients requiring parenteral nutrition
standard monitoring of nutritional status and renal function
renal_impairment
mild to moderatemonitor amino acid levels
may require monitoring of nitrogen balance and amino acid levels
regular monitoring of renal function and amino acid levels
Use with caution and monitor for adverse effects.
renal_impairment
severeadjust based on clinical assessment
use with caution and monitor closely
frequent monitoring of renal function and amino acid levels
Use with caution and monitor for adverse effects.
hepatic_impairment
mild to moderatemonitor liver function
use with caution in patients with hepatic impairment
monitor liver function tests and amino acid levels
Use with caution and monitor for adverse effects.
hepatic_impairment
severeadjust based on clinical assessment
use with caution and monitor closely
frequent monitoring of liver function and amino acid levels
Use with caution and monitor for adverse effects.
Statistics and clinical data
Commonly prescribed since
Parenteral nutrition formulations containing amino acids including Tryptophan have been available since the 1960s
Drug class
Tryptophan is classified as an essential amino acid used in parenteral nutrition formulations
Common uses
Used for patients requiring intravenous nutritional support who cannot receive oral or enteral nutrition
Mechanism of action
Tryptophan serves as a precursor for serotonin and melatonin synthesis
Prescription tryptophan is used for the treatment of depression, particularly when associated with anxiety or insomnia. It may also be used for sleep disorders, premenstrual syndrome, and as an adjunct in smoking cessation programs.
Tryptophan is converted to 5-hydroxytryptophan (5-HTP), which is then converted to serotonin. Adequate serotonin levels are associated with improved mood, better sleep quality, and reduced anxiety. Tryptophan may also be converted to melatonin, which regulates the sleep-wake cycle.
Tryptophan should not be combined with selective serotonin reuptake inhibitors (SSRIs), MAO inhibitors, or other serotonergic medications due to the risk of serotonin syndrome. It may cause drowsiness, so caution is advised when driving or operating machinery. Use under medical supervision is recommended, particularly for patients with psychiatric conditions.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy