ABSTRACT In response to nutrients, intestinal L‐ and K‐cells naturally secrete glucagon‐like peptide 1 (GLP‐1). GLP‐1 regulates postprandial blood glucose by increasing insulin secretion, slowing down gastric emptying and inducing satiety. A selection of specifically developed collagen hydrolysates was screened for their ability to enhance natural GLP‐1 production in vitro. The best performing hydrolysate, H80 (Nextida GC), was orally administered at different doses to lean, normoglycemic mice and overweight, prediabetic mice. Lean mice were acutely challenged 45 min before an oral glucose load. While daily supplemented for 6 weeks, prediabetic mice were acutely challenged at day 21 and 34. Oral glucose tolerance, plasma insulin and GLP‐1 levels were assessed, and a gastric emptying assay performed in prediabetic mice. H80 significantly lowered the blood glucose response in lean and prediabetic mice, at a 4 g/kg dose (−25% and −36%, respectively), compared to vehicle. In chronically supplemented, prediabetic mice, acute H80 administration slowed down gastric emptying (−60%) after 21 days and increased plasma insulin (+166%) after 35 days of supplementation. H80 increased plasma active GLP‐1 in lean (+217%) and prediabetic (+860%) mice. Overall, the data indicate that the specific collagen hydrolysate, H80, has significant GLP‐1‐mediated effects on oral glucose tolerance in lean and prediabetic mice. Furthermore, effects on postprandial glucose tolerance were evaluated in a small, human, proof of concept study. H80 reduced the postprandial glucose response at a 5 g dose in healthy, normoglycemic and prediabetic participants. Oral supplementation with H80 might thus be a promising strategy to maintain normal glucose tolerance.