The present invention relates to a compound comprising a PYY peptide or a
functional derivative thereof, which is coupled to a reactive group. Such
a reactive group is capable of reacting on a blood component so as to
form a stable covalent bond therewith. The present invention also relates
to a conjugate comprising such a compound which is covalently bonded to a
blood component. Moreover, the invention also relates to a method of
enhancing, in a patient, the anti-obesity activity of a PYY peptide or
functional derivative thereof.