Acute Effect of a Proprietary Blend Containing L-Arginine and Antioxidants on GLP-1 Release

Type: Graduate
Author(s): Katie Harnen Nutritional Sciences
Advisor(s): Elisa Marroquin Nutritional Sciences Elisa Marroquin Nutritional Sciences Ryan Porter Interdisciplinary

Background: Glucagon-like peptide 1 (GLP-1) is a key gut hormone regulating glucose homeostasis and satiety. This triple-blind, crossover, placebo-controlled randomized study investigated the effect of an L-Arginine-based supplement on active GLP-1 secretion, appetite, and food intake.

Methods: Sixteen participants (N=16) completed three conditions: a placebo and two doses of the supplement (Low-Dose, 5g; High-Dose, 10g). Supplements were consumed at time 0, and an ad libitum meal was consumed at 60 minutes. Serum samples were collected at eight time points over 120 minutes to assess circulating active GLP-1 levels.

Results: Supplementation with L-Arginine significantly augmented circulating GLP-1 levels compared to the control condition. Both doses triggered an immediate, transient rise in GLP-1, followed by a robust and significantly enhanced post-meal response relative to placebo. Analysis of the Area Under the Curve (AUC) confirmed this finding: total GLP-1 exposure was 607% greater in the High-Dose group (~ 340n pg/ml/min, p < 0.0001) and 544% greater in the Low-Dose group (~130 pg/ml/min, p = 0.0076) compared to placebo (~ 50 pg/ml/min). No significant differences in GLP-1 concentrations were observed between the two supplement doses. Secondary analyses found no differences in subsequent food intake or subjective hunger ratings between conditions, a result likely limited by the study’s power for these secondary variables (eta ~ 0.023).

Conclusions: L-Arginine is a potent secretagogue for GLP-1. These findings demonstrate that supplementation significantly increases the body's overall exposure to this crucial gut hormone, suggesting a potential role for L-Arginine in supporting metabolic health.