The anti-wrinkle Botox injection may work as a therapy for chronic migraines, Allergan Inc said on Thursday. "We are pleased with the top-line results of our Phase III clinical trials which show that Botox treatment provided benefit to these patients whose lives have been profoundly impacted by this severely debilitating condition," said Scott Whitcup, MD, Allergan's EVP, research and development."

The company will seek U.S. approval to market Botox for headaches. Shares of the drug maker were trading up 5.4% to $57.50 on the news. Allergan hopes to file a biologics license application with the U.S. Food and Drug Administration in order to use Botox in chronic migraine by the middle of 2009.

Besides its being a beauty enhancer, this substance is already approved for, among other things, treating cervical dystonia, nerve and muscle spasms and excessive armpit sweating. So this is not the first time scientists have used it in medical purposes. Its use is recommended for people who suffer from headaches that occur at least 15 days a month.

Data from its Phase III clinical trials showed a significantly greater decrease in the number of headache days among patients receiving Botox, as compared with those receiving a placebo.

Botulinum toxin is a neurotoxin protein produced by the bacterium Clostridium botulinum. It is one of the most poisonous naturally occurring substances. But used in very small quantities it is not harmful. As of 2007, Botox injection is the most common cosmetic operation, with 4.6 million procedures in the United States.