Entero-pancreatic hormone secretion is thought to include a cephalic phase but the evidence in humans is ambiguous. We studied vagally-induced gut hormone responses with and without muscarinic blockade in ten glucose-clamped healthy males (age: 24.5±0.6 years(mean±standard error of the mean (SEM); body mass index: 24.0±0.5kg/m2; HbA1c: 5.1±0.1% /31.4±0.5mmol/mol). Cephalic activation was elicited by modified sham feeding (MSF, aka "chew and spit") with or without atropine (1mg bolus 45min before MSF + 80ng/kg/min for 2h). To mimick incipient prandial glucose excursions, glucose levels were clamped at 6mmol/L on all days. The meal stimulus for the MSF consisted of an appetizing breakfast. Participants (9/10) also had a 6mmol/L-glucose clamp without MSF. PP levels rose from 6.3±1.1 to 19.9±6.8pmol/L(means±SEM) in response to MSF and atropine lowered basal PP levels and abolished the MSF response. Neither insulin, C-peptide, glucose-dependent insulinotropic polypeptide(GIP) nor glucagon-like peptide-1(GLP-1) levels changed in response to MSF or atropine. Glucagon and ghrelin levels were markedly attenuated by atropine prior to and during the clamp: at t=105min on the ATR+CLA+MSF compared to the SAL+CLA and SAL+CLA+MSF days; baseline-subtracted glucagon levels were -10.7±1.1 vs. -4.0±1.1 and -4.7±1.9pmol/L(mean±SEM),P<0.0001), respectively; corresponding baseline-subtracted ghrelin levels were 303±36 vs. 39±38 and 3.7±21pg/mL(mean±SEM), P<0.0001. Glucagon and ghrelin levels were unaffected by MSF. In spite of adequate PP responses, a cephalic phase response was absent for insulin, glucagon, GLP-1, GIP and ghrelin.