L-Tryptophan Clinical Trials

Size	Price	Qty
25mg	USD 147
1g	USD 970

Clinical Trials

Multiple clinical trials investigate L-tryptophan across conditions including major depressive disorders, gastrointestinal diseases, neuroendocrine neoplasms, and healthy aging. Spanning Phase 1 through Phase 3 along with exploratory studies, these trials are sponsored by academic medical centers, hospital systems, and research institutes, with statuses ranging from completed and actively recruiting to withdrawn. Ultimately, this body of research underscores L-tryptophan’s utility as both a therapeutic agent and diagnostic biomarker substrate in psychiatric, metabolic, and oncological medicine.

NCT Number	Recruitment	Conditions	Sponsor/Collaborators	Start Date	Phases
NCT05556473	RECRUITING	Intracranial Glioma; Metastatic Brain Tumor; Breast Cancer; Neuroendocrine Tumors; Rectal Cancer	Barbara Ann Karmanos Cancer Institute	2022-09-29	PHASE1
NCT07013656	NOT_YET_RECRUITING	Healthy	University of Adelaide	2025-06-28
NCT05576038	RECRUITING	Tryptophan Metabolism Alterations; Celiac Disease	McMaster University	2022-12-01
NCT06089811	UNKNOWN	Stress, Psychological	KU Leuven	2023-10-10
NCT06283706	Not yet recruiting	Healthy Aging	The Hospital for Sick Children\|Canadian Institutes of Health Research (CIHR)	2024-06-01	Not Applicable
NCT06365801	Not yet recruiting	Irritable Bowel Syndrome	The Third Affiliated hospital of Zhejiang Chinese Medical University	2024-04	--
NCT06228352	Not yet recruiting	Ulcerative Colitis	Assistance Publique - Hôpitaux de Paris	2024-03	--
NCT06021535	Not yet recruiting	Aortic Stenosis\|Gastrointestinal Microbiome\|Metabolomics	Insel Gruppe AG University Hospital Bern	2024-01-01	--
NCT03089606	COMPLETED	Melanoma	UNC Lineberger Comprehensive Cancer Center	2017-04-19	PHASE2
NCT03453489	COMPLETED	Carcinoid Syndrome; Metastatic Nonfunctional Well Differentiated Neuroendocrine Neoplasm	Barbara Ann Karmanos Cancer Institute	2018-06-20	PHASE2
NCT04505800	COMPLETED	Sleep; Mood; Burnout; Melatonin Deficiency; Cortisol Deficiency	National Yang Ming Chiao Tung University	2019-09-01
NCT04117191	COMPLETED	Healthy; Chronic Kidney Diseases	Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation	2019-10-01
NCT03059862	COMPLETED	Diet Modification	McMaster University	2017-11-01
NCT02223299	WITHDRAWN	Depression	John D. Dingell VA Medical Center	2015-11
NCT02823249	COMPLETED	Endocrine System Diseases	University Hospital, Basel, Switzerland	2014-05
NCT02563847	COMPLETED	Endocrine System Diseases	University Hospital, Basel, Switzerland	2014-05
NCT01302821	WITHDRAWN	Breast Cancer	H. Lee Moffitt Cancer Center and Research Institute	2013-01
NCT00865202	COMPLETED	Post-operative Delirium	University of Colorado, Denver	2008-12	PHASE3

(data from https://clinicaltrials.gov, updated on 2026-01-23)

Check the L-Tryptophan product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.

Compliance for Clinical Use

Mechanism and Biochemical Profile

As an essential amino acid, L-tryptophan serves as a metabolic substrate for rate-limiting enzymes such as tryptophan hydroxylase and indoleamine 2,3-dioxygenase, driving downstream biochemical cascades that synthesize serotonin, melatonin, and kynurenine pathway intermediates. These downstream metabolites modulate neurotransmitter receptor signaling, cellular immune responses, and mucosal homeostasis, providing direct therapeutic and diagnostic relevance to clinical trial indications including depressive disorders, inflammatory bowel conditions, and neuroendocrine neoplasms.

Appendix RUO and cGMP Quality Standards

Quality Dimension	RUO (Research Use Only)	cGMP (Current Good Manufacturing Practice)
Clinical Applicability	Prohibited in human clinical trials or medical diagnostics.	Mandatory for human clinical trials (Phase I–III) and therapies.
Regulatory Status	Non-regulated grade; exempt from drug manufacturing laws.	Legally enforced by health authorities (e.g., FDA, EMA, NMPA).
Facility Environment	Unclassified analytical or research laboratories.	Validated Cleanrooms (ISO Class 5–8) with continuous monitoring.
Quality Control	Basic purity and activity testing.	Rigorous safety release testing (Sterility, Endotoxin, Mycoplasma).
Process Validation	Basic equipment calibration; no process validation required.	Full qualification (IQ/OQ/PQ) and complete batch records.
Quality Assurance	Vendor self-declared without required formal QMS.	Mandatory QA/QC unit, Change Control, CAPA, and vendor audits.
Regulatory Impact	High risk of IND rejection if used as a critical raw material.	Required for IND/NDA filings, supported by Drug Master Files (DMF).

Footnotes

Regulatory Note: Governed by FDA (21 CFR Parts 210/211/312), EMA (EudraLex Vol 4), ICH Guidelines (E6/Q7/Q9/Q10), and compendial standards (USP <71>/<85>/<1043>).