The Effect of Griffonia Simplicifolia on Pain Intensity, Central and Peripheral Sensitization, Painmodulation in Healthy Volunteers

This planned study is based on a randomized, placebo-controlled cross-over design. Griffonia simplicifolia contains the serotonin-precursor 5-hydroxytryptophan (5-HTP), an endogenous amino acid. 5-HTP can cross the blood-brain barrier and is converted to serotonin. Low serotonin levels are associated with depression, anxiety disorders and sleep disorders, among others. Griffonia simplicifolia is marketed as a food supplement in accordance with EU Directive 2002/46/EC. Several clinical studies have examined the efficacy of 5-HTP in chronic pain conditions. The data suggest a clinical analgesic efficacy, without, however, allowing conclusions about the underlying mechanisms. These have not yet been investigated in a human experimental pain model. The aim of the study is to investigate the influence of 5-HTP in peripheral and central sensitization, as well as descending inhibitory pathways by Quantitative Sensory Testing (QST). These findings are of great relevance for a better understanding of clinical efficacy. For this purpose, "repetitive phasic heat application" is a validated method for achieving short-term peripheral and central sensitization. As a non-invasive human pain model, it is therefore well suited for investigating the analgesic and anti-hyperalgesic effects of drugs. Furthermore, the influence of Griffonia simplicifolia on mood (depression, anxiety), memory, sleep quality and psychological well-being will be investigated by using psychological questionnaires as secondary target variables.

NCT Number	NCT06893822
Lead Sponsor	Medical University of Graz
Conditions	Chronic Pain, Central Sensitisation, Peripheral Sensitization, Neuroinflammatory Response
Enrollment	20 participants
Start Date	2025-09-12
Primary Completion	2025-12-20 (estimated)
Study Completion	2025-12-20 (estimated)
Updated on ClinicalTrials.gov	2025-06-17