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

Background: Peptide YY (PYY(3-36)) infused to levels within the physiological range reduces appetite and food intake in humans without nausea. However, PYY(3-36) has previously been shown to cause nausea at higher doses.

Methods: We studied the relationship of PYY(3-36), nausea and food intake in six volunteers, using three different PYY(3-36) preparations infused to achieve supraphysiological PYY plasma levels.

Results: Supraphysiological levels of PYY caused nausea in five subjects (P < 0.05). Although PYY(3-36) 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 PYY(3-36) as it may increase nausea with no benefit in food reduction.