Why Did my Botox Only Last Two Months in Forehead?

There is a clinical correlation between dose and duration of botulinum toxin (Botox, Dysport, Xeomin) up to a point.  This means that the effect of a very tiny dose of botulinum toxin is usually diminished well before the effects of large doses.  Once a certain dose is reached, administering more drug does not increase duration further.  The actual duration of effect will vary from patient to patient.

Typically botox lasts about four months, however, sometimes it may not last as long. I have found that if it wears off between injections a touch-up can enhance the results and can it help it last the expected time.