The present invention provides a modified BoNT/A for use in treating facial lines, wherein the modified BoNT/A is administered by intramuscular injection at a plurality of sites of the face of the subject, wherein the modified BoNT/A is administered by way of a unit dose of greater than 1754 pg or greater than 8000 pg) of modified BoNT/A per site, wherein the plurality of sites are selected from: up to two sites of a corrugator muscle and one site of a procerus muscle for treating glabellar lines, up to five sites of a frontalis muscle for treating forehead lines, and up to three sites of an orbicularis oculi muscle for treating lateral canthal lines, wherein the total dose of modified BoNT/A administered during the treatment is up to 264,000 pg (and optionally greater than 88,000 pg), and wherein the modified BoNT/A comprises a BoNT/A light-chain and translocation domain (HN domain), and a BoNT/B receptor binding domain (HC domain).