Effects of 5HTP on spinal cord injuries

Effects of the Serotonin Precursor, 5-hydroxytryptophan, in the Injured Human Spinal Cord

Phase2; Phase3 Interventional University of Alberta · NCT04520178

This study is testing if a supplement called 5-HTP can help improve muscle function and nervous system activity in people with spinal cord injuries.

Quick facts

PhasePhase2; Phase3
Study typeInterventional
Enrollment30 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorUniversity of Alberta Academic / other
Locations2 sites (Louisville, Kentucky and 1 other locations)
Trial IDNCT04520178 on ClinicalTrials.gov

What this trial studies

This study investigates the impact of 5-HTP, a serotonin precursor, on nervous system excitability and motor function in individuals with spinal cord injuries of varying severity and chronicity. Participants will undergo a randomized, double-blinded, placebo-controlled crossover design, receiving four different treatments across four visits. The study aims to understand how 5-HTP, when co-administered with carbidopa to minimize side effects, affects neurophysiological outcomes and functional improvements in muscle activation during cycling. It will include subacute and chronic spinal cord injury patients categorized by their American Spinal Injury Association (ASIA) impairment scale scores.

Who should consider this trial

Good fit: Ideal candidates are individuals who have suffered a spinal cord injury at least six months prior, with varying degrees of injury severity.

Not a fit: Patients with other nervous system damage, significant comorbidities, or those currently on certain medications may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved motor function and quality of life for patients with spinal cord injuries.

How similar studies have performed: While the use of 5-HTP in this context is novel, previous studies have shown promise in using serotonin precursors for neurological conditions.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* participants must have suffered trauma to the spinal cord at least six months ago or longer

Exclusion Criteria:

* individuals with damage to the nervous system other than to the spinal cord
* pregnant and/or breastfeeding women
* alcoholic participants
* history of seizure/epilepsy
* history of suicidal thoughts or behaviors
* known or suspected allergy to the medication ingredients
* cardiovascular disease including history of heart attack or heart rhythm irregularities
* coronary artery disease
* reduced liver function or disease
* reduced kidney function or disease
* lung disease
* comatose or depressed states due to CNS depressants
* endocrine dysfunction
* blood dyscrasias or blood related disease
* bone marrow depression
* hypocalcemia
* history of stomach ulcers
* wide angle glaucoma
* phenylketonuria
* history of tumors
* uncontrolled heart problems
* unstable psychiatric or mental disorder

Participants taking:

* monoamine oxidase inhibitor therapy
* serotonergic antidepressants
* tricyclic antidepressants
* any type of serotonergic agonist
* dopamine D2 receptor antagonists
* amphetamine
* CNS depressants
* levodopa
* lithium
* anti-hypertensive drugs
* iron salts
* metoclopramide
* phenothiazine medication

Where this trial is running

Louisville, Kentucky and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Spinal Cord Injuries
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.