The anti-wrinkle drug Botox, derived from a deadly botulism toxin, is often portrayed as entirely safe—but it isn’t, says a new FDA report. Botox smoothes facial wrinkles by paralyzing muscles under the skin. The toxin has medical uses as well: Injections of Botox in the legs or neck can be helpful for cerebral palsy patients suffering from severe muscle spasms. But in rare cases, the FDA warns, the toxin can spread from the site of the injection and cause paralysis in other parts of the body. Dozens of negative reactions have been reported, including several children with cerebral palsy who died when the toxin spread from their injected muscles and prevented them from breathing. At least one woman who received Botox for cosmetic reasons was hospitalized after the toxin affected other muscles. “People should be aware there’s a potential for this to happen,’’ says FDA neurology chief Dr. Russell Katz. Botox users, he says, should be on alert for symptoms such as difficulty swallowing or breathing, slurred speech, muscle weakness, or difficulty holding up the head.