L-Tryptophan

An essential amino acid that is a precursor to serotonin and melatonin.

Also known as: Tryptophan

other Names
Tryptophan
primary Benefits
Promotes sleep, improves mood, and reduces anxiety.
common Dose
500-2000 mg per day.
best Form
L-Tryptophan
timing
Take 30-60 minutes before bedtime for sleep.
safety Rating
Generally Safe

Overview

L-Tryptophan is an essential amino acid, meaning it cannot be synthesized by the body and must be obtained from the diet. It is a precursor to several important molecules, including the neurotransmitter serotonin and the hormone melatonin. Serotonin plays a crucial role in regulating mood, appetite, and sleep, while melatonin is responsible for regulating the sleep-wake cycle. Due to its role in serotonin and melatonin production, L-tryptophan is often used as a supplement to improve mood, reduce anxiety, and promote sleep. It is also involved in the synthesis of niacin (vitamin B3) and other important proteins in the body.

Key Benefits

Promotes Sleep

As a precursor to melatonin, L-tryptophan can help improve sleep quality and reduce the time it takes to fall asleep.

Improves Mood

By increasing serotonin levels, L-tryptophan may help improve mood and reduce symptoms of depression.

Reduces Anxiety

Increased serotonin levels may also help reduce feelings of anxiety and promote a sense of calm.

Dosage & How to Take

Dosage can vary depending on the intended use. It is best to start with a lower dose and gradually increase as needed.

PurposeDoseNotes
Sleep1000-2000 mg per dayTaken 30-60 minutes before bedtime.
Mood Support500-1500 mg per dayTaken in divided doses.

Best Time to Take

For sleep, take before bedtime. For mood support, it can be taken throughout the day.

With or Without Food

Best taken on an empty stomach to avoid competition with other amino acids for absorption.

Forms & Bioavailability

FormAbsorptionBest ForNotes
L-TryptophanHighGeneral supplementation.The natural and most common form of tryptophan.
5-HTPHighMore direct conversion to serotonin.A metabolite of tryptophan that is closer to serotonin in the metabolic pathway.

Side Effects & Safety

Common

  • Drowsiness
  • Stomach pain
  • Vomiting

Rare

  • Headache
  • Dizziness

Contraindications

  • Should not be taken with SSRIs or other antidepressant medications without medical supervision.

Interactions

SSRIsSevere

May increase the risk of serotonin syndrome.

MAOIsSevere

May increase the risk of serotonin syndrome.

Scientific Research

2009PMC

L-Tryptophan: Basic Metabolic Functions, Behavioral Research and Therapeutic Indications

L-tryptophan is critical in a number of metabolic functions and has been widely used in numerous research and clinical applications.

2016PMC

Influence of Tryptophan and Serotonin on Mood and Cognition with a Possible Role of the Gut-Brain Axis

Tryptophan supplementation may improve mood and cognitive function.

Food Sources

Turkey
Chicken
Eggs
Cheese
Nuts
Seeds

Products With L-Tryptophan

2 products in our database contain this ingredient

Frequently Asked Questions

Medical Disclaimer

This content is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen, especially if you have pre-existing health conditions or are taking medications. The statements on this page have not been evaluated by the Food and Drug Administration.