Who knew that vanity could yield a new treatment for pain? After some patients who received Botox injections to prevent wrinkles in their forehead reported that their migraines also seemed to diminish, scientists — especially those at Allergan, the manufacturer of Botox — decided to investigate. Based on data from two large trials involving more than 1,000 patients, the company successfully convinced the Food and Drug Administration (FDA) that patients receiving Botox in the facial area experienced fewer days of migraine pain each month than those who did not get the muscle paralyzing injections. The FDA approval means that insurers may start covering the cost of Botox, which can cost thousands of dollars over several months, to treat migraines. It's still difficult to predict which headache patients will benefit the most, say experts, but at least migraine sufferers won't have to visit the plastic surgeon on the sly to relieve pain — or pay for treatments out of pocket.