Botox typically starts to work within 2 to 4 days after the injection, with noticeable improvements beginning during this period. The maximum effects of Botox can be seen around 7 to 14 days after treatment, though this varies depending on the individual and treatment area. The results usually last for about 3 to 4 months. Factors influencing the onset and duration include your age, muscle mass, gender, injection volume, and type of Botox used.