Masseter botox reshaping is gradual; expect contour changes over 4 to 8 weeks as the muscle atrophies slightly

https://www.scribd.com/document/1018428753/Botox-Long-Term-Effects-What-We-Know-216165

Masseter botox reshaping is gradual; expect contour changes over 4 to 8 weeks as the muscle atrophies slightly, with results lasting several months before a maintenance dose.