Attenuation of Fasting and Postprandial Glucose Exposure by Standardized Salacia reticulata Extract in Adults with Prediabetes: A Randomized, Double-Blind, Placebo-Controlled Trial

Clinical evidence for Salacia reticulata extract (SR) in prediabetes remains limited, particularly with respect to its effects on comprehensive glucose exposure across multiple oral glucose tolerance test (OGTT)-derived intervals. This randomized, double-blind, placebo-controlled trial evaluated the effects of a standardized SR administered for 12 weeks on fasting and postprandial glucose exposure in adults with prediabetes. One hundred participants meeting prediabetes criteria (fasting plasma glucose [FPG] 100–139 mg/dL and postprandial plasma glucose [PPG] 140–199 mg/dL) were selected. Participants with dual fasting and postprandial glycemic impairments were randomly assigned to receive SR (500 mg/day, n = 50) or placebo ( n = 50). Efficacy and safety outcomes were assessed at baseline and after the intervention. Compared with placebo, SR significantly reduced FPG and PPG to 90 and 120 min after supplementation (all P < .05). Glucose areas under the curve at 0–30, 0–60, 0–90, and 0–120 min were significantly lower in the SR group compared with placebo, with significant percent reductions in postprandial glucose spikes from baseline to week 12 (all P < .05). Additionally, HbA1c and triglycerides were significantly reduced, while 1,5-anhydroglucitol was significantly increased compared with placebo. Total glucagon-like peptide-1 (GLP-1) levels showed a significant between-group difference. No clinically meaningful safety concerns were observed. Twelve weeks of supplementation with standardized SR attenuated fasting and postprandial glucose concentrations, including significant reductions in OGTT-derived glucose spikes. These findings extend clinical evidence of S. reticulata to early-stage dysglycemia and support its potential role in glycemic stabilization in prediabetes.