DENVER -- Botulinum toxin has been linked to cases of serious reactions, including death, said the Food and Drug Administration.

As a result, the FDA is now slapping a black-box label on the product best known for smoothing wrinkles.

The FDA said most of the severe reactions are the result of off-label use. Botox is frequently used to treat muscle spasms in cerebral palsy patients.

Dr. Dennis Matthews, at The Children's Hospital in Aurora, said he uses it about five times a day.

"Botox is not approved for the use of spacity but it's been used off-label since 1991," said Matthews.

Matthews called it a huge asset to children and did not think parents should be overly concerned but should be aware of the risks.

Still, in his ten years of using it he said there had only been one case involving a child who had trouble swallowing.

At Beauty by Buford, in Englewood, business is booming.

Nurse practitioner Patricia Ritter said she is seeing three to five more patients a day in this economy. Ritter said women are electing to have botox because it's cheaper and feel the need to look their best in this competitive market.

She said they always encourage patients to do their research before coming to the clinic and said patients can request to look at the botox vials to make sure they aren't generic products and are approved by the FDA.

Doctors in the area said they believe some of the hype surrounding botox has to do with unscrupulous clinics purchasing "bathtub" botox at a discount rate.