Abstract: An isolated, synthetic or recombinant ?-conotoxin peptide comprising the following sequence of amino acids: Xaa1 Xaa2 Gly Val Cys Cys Gly Tyr Lys Leu Cys His Pro Cys SEQ ID NO. 3 where Xaa1 is a N-terminal Xaa1 is a N-terminal pyroglutamate (pGlu) or D-pyroglutamate (DpGlu) residue; and Xaa2 is Asn or a deletion; or such a sequence in which one or more Cys is replaced with its corresponding D-amino acid and/or one or more amino acid residues other than Cys has undergone a side chain modification, or a salt, ester, amide or prodrug thereof. The invention also relates to pharmaceutical compositions comprising these peptides and the use of these peptides in the prophylaxis or treatment of conditions, such as but not limited to, pain, inflammation, incontinence, cardiovascular conditions and mood disorders.