Supraphysiological doses of intravenous PYY3-36 cause nausea, but no additional reduction in food intake

Background: Peptide YY (PYY3-36) infused to levels within the physiological range reduces appetite and food intake in humans without nausea. However, PYY3-36, has previously been shown to cause nausea at higher doses. Methods: We studied the relationship of PYY3-36, nausea and food intake in six volunteers, using three different PYY3-36 preparations infused to achieve supraphysiological PYY plasma levels. Results: Supraphysiological levels of PYY caused nausea in five subjects (P < 0.05). Although PYY3-36 increased satiety (P < 0.05) and reduced food intake (P < 0.05), no greater enhancement of satiety or inhibition of food intake was observed compared with previous reports. Conclusions: This study cautions against the use of supraphysiological doses of PYY3-36 as it may increase nausea with no benefit in food reduction.