Side Effects of Botox Linked to Muscle Atrophy Throughout Body: Study

Canadian researchers say that injections of Botox, which are commonly used for cosmetic surgery and in some cases for off-label treatment of cerebral palsy, could be causing muscles to atrophy in areas outside of the injection site. 

During a study conducted by researchers at the University of Calgary, rabbits injected with botulinum toxin A, more often known as Botox, experienced muscle loss and atrophy after receiving the injections. Most surprising to the researchers was that, over the course of six months, the effects seemed to radiate throughout the rabbits’ bodies, far from the injection site. The Botox study will be published in an upcoming issue of the Journal of Biomechanics.

The findings of prior studies have suggested that Botox side effects may affect muscles in the immediate vicinity of the injection, but this is the first time a study has shown a potential link between Botox injections and the loss of muscle mass and structural integrity elsewhere in the body.

Botox, which contains small quantities of the bacteria associated with the development of botulism poisoning, is approved for both cosmetic use to reduce the appearance of wrinkles in the skin and to treat medical conditions such as strabismus (crossed eyes), hyperhidrosis (excess sweating), cervical dystonia (involuntary contractions of the neck muscles) and blepharospasms (involuntary blinking of the eye). However, it also commonly used off-label at high doses to treat stiff and jerky movements associated with cerebral palsy in children.

A number of problems with Botox have been reported among users, where the medication can spread from the area of the injection to other parts of the body. This can result in symptoms of botulism poisoning, such as paralysis, difficulty swallowing, respiratory distress and other issues. These side effects of Botox have most commonly been seen among children with cerebral palsy, where the typical Botox dose is substantially larger.