Federal health officials approved the wrinkle-smoothing injection Botox for migraine headaches on Friday, giving drugmaker Allergan clearance to begin marketing its drug to patients with a serious history of the condition.

The Food and Drug Administration approved the drug for patients who experience 15 or more days of migraine headaches per month. Allergan, which specializes in beauty and eye-care drugs, said roughly 3.2 million people in the U.S. have chronic migraines.

For the new use, doctors are directed to inject patients in the neck or head every 12 weeks to dull future headaches.