General Dosage
500 mg-2 g daily, typically taken before bed
Maximum dose: 6 g/day has been used in clinical research; doses above 3 g may cause GI upset and drowsiness
L-Tryptophan Dosage Guide
Evidence:Moderate
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Dosage Recommendations
General recommendation: 500 mg-2 g daily, typically taken before bed
Timing: Before bed for sleep; with carbohydrates to enhance brain uptake • Take with food for best absorption.
Dosage by Condition
Sleep support
1-2 g 30-45 min before bedModerate
Mood support
1-3 g dailyModerate
Mild depression
2-3 g daily in divided dosesModerate
| Condition | Recommended Dose | Evidence |
|---|---|---|
| Sleep support | 1-2 g 30-45 min before bed | Moderate |
| Mood support | 1-3 g daily | Moderate |
| Mild depression | 2-3 g daily in divided doses | Moderate |
Upper limit: 6 g/day has been used in clinical research; doses above 3 g may cause GI upset and drowsiness
Timing & Absorption
Before bed for sleep; with carbohydrates to enhance brain uptake
Best taken with food for optimal absorption.
References
- ReviewSilber BY, Schmitt JA. (2010). Effects of tryptophan loading on human cognition, mood, and sleep. Neuroscience & Biobehavioral Reviews. DOI PubMed
- RCTMurphy SE, Longhitano C, Ayres RE, et al. (2006). Tryptophan supplementation induces a positive bias in the processing of emotional material in healthy female volunteers. Psychopharmacology. DOI PubMed
- Meta-analysisOgawa S, Fujii T, Koga N, Hori H, et al. (2014). Plasma L-tryptophan concentration in major depressive disorder: new data and meta-analysis.. The Journal of clinical psychiatry. DOI PubMed
- Meta-analysisKikuchi AM, Tanabe A, Iwahori Y (2021). A systematic review of the effect of L-tryptophan supplementation on mood and emotional functioning.. Journal of dietary supplements. DOI PubMed
- ReviewCarneiro IBC, Toscano AE, Lacerda DC, da Cunha MSB, et al. (2018). L-tryptophan administration and increase in cerebral serotonin levels: Systematic review.. European journal of pharmacology. DOI PubMed
- Getirana-Mota M, Aidar FJ, de Souza RF, Brito CJ, et al. (2026). The Effect of L-Tryptophan Intake on Dynamic Strength in Paralympic Powerlifting.. International journal of tryptophan research : IJTR. DOI PubMed
- Khan S, Iqbal MZ, Solangi F, Azeem S, et al. (2025). Impact of amino acid supplementation on hydroponic lettuce (Lactuca sativa L.) growth and nutrient content.. Scientific reports. DOI PubMed
Show 3 more references
- Rueda GH, Causada-Calo N, Borojevic R, Nardelli A, et al. (2024). Oral tryptophan activates duodenal aryl hydrocarbon receptor in healthy subjects: a crossover randomized controlled trial.. American journal of physiology. Gastrointestinal and liver physiology. DOI PubMed
- Jiang L, Wang J, Xu L, Cai J, et al. (2022). Lactobacillus casei modulates inflammatory cytokines and metabolites during tuberculosis treatment: A post hoc randomized controlled trial.. Asia Pacific journal of clinical nutrition. DOI PubMed
- Ferguson C, Aisbett B, Lastella M, Roberts S, et al. (2022). Evening Whey Protein Intake, Rich in Tryptophan, and Sleep in Elite Male Australian Rules Football Players on Training and Nontraining Days.. International journal of sport nutrition and exercise metabolism. DOI PubMed