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L-Tryptophan
L-Tryptophan is an essential amino acid that serves as a precursor for serotonin and melatonin synthesis, supporting neurotransmitter production and mood regulation.
L-Tryptophan is an essential amino acid that serves as a precursor for serotonin and melatonin synthesis, supporting neurotransmitter production and mood regulation. Used for Depression and mood disorders, Sleep disorders and insomnia, Anxiety disorders.
At a glance
| Generic name | L-Tryptophan |
|---|---|
| Sponsor | McMaster University |
| Drug class | Amino acid supplement |
| Modality | Small molecule |
| Therapeutic area | Psychiatry/Neurology |
| Phase | FDA-approved |
Mechanism of action
L-Tryptophan is metabolized via the kynurenine pathway and the serotonin pathway. In the serotonin pathway, it is converted to 5-hydroxytryptophan (5-HTP) by tryptophan hydroxylase, which is then decarboxylated to serotonin, a key neurotransmitter involved in mood, sleep, and anxiety regulation. It also serves as a precursor for melatonin synthesis, supporting circadian rhythm regulation.
Approved indications
- Depression and mood disorders
- Sleep disorders and insomnia
- Anxiety disorders
Common side effects
- Nausea
- Headache
- Drowsiness
- Gastrointestinal upset
Key clinical trials
- Testing the Addition of Darolutamide to Hormonal Therapy (Androgen Deprivation Therapy [ADT]) After Surgery for Men With High-Risk Prostate Cancer, The ERADICATE Study (PHASE3)
- Plant Protein With Ashwagandha-Rhodiola for Sleep Quality (NA)
- Tryptophan as a Modulating Factor in the Antimigraine Efficacy of Triptans
- 5HTP Regulation Of Asthma In Children (PHASE2)
- Treating Prostate Cancer That Has Come Back After Surgery With Apalutamide and Targeted Radiation Based on PET Imaging (PHASE3)
- Fecal Microbiota And Metabolites In Head And Neck Cancer Patients Receiving (Chemo)Radiotherapy (NA)
- The Effects of Kynurenine Aminotransferase Inhibition in People With Schizophrenia (PHASE1, PHASE2)
- Suppression of Ovarian Function With Either Tamoxifen or Exemestane Compared With Tamoxifen Alone in Treating Premenopausal Women With Hormone-Responsive Breast Cancer (PHASE3)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- L-Tryptophan CI brief — competitive landscape report
- L-Tryptophan updates RSS · CI watch RSS
- McMaster University portfolio CI