For treating horizontal forehead lines with Botox, the typical dosage ranges from 10 to 30 units , depending on factors such as the severity of wrinkles, muscle strength, and forehead size

• Allergan, the manufacturer of Botox, suggests injecting 4 units at five sites on the forehead, totaling 20 units as a common starting point

• Some practitioners recommend starting with a lower dose and adjusting based on the patient's response after 1 to 2 weeks

• For moderate to severe forehead lines, doses toward the higher end of the 10-30 unit range may be needed

• Botox injections for the forehead are usually spaced about 3 to 4 months apart

Additionally, when Botox is used to treat both forehead lines and glabellar lines (the "11" lines between the eyebrows), the combined dose can be up to 40 units (20 units for the forehead and 20 units for the glabella)

. In summary, most patients receive between 10 and 30 units of Botox for forehead lines, with 20 units being a common standard dose, adjusted per individual needs by a qualified practitioner to avoid side effects like drooping eyelids