Botox HOME
Your Online Resource Centre for Botox Information.
Skin Care Guide Canada
Botox Facts About Us Dermatology Glossary and Images Skin Care Network Botox Site Map



Botox: Side Effects & Safety

As with any medication, potential side effects of Botox® do exists, and vary according to injection site, dose, frequency of injections, and the amount of physician expertise. Most side effects— such as pain, tenderness, or bruising at the injection site—are temporary and occur within a few days after treatment.

The most common side effects of injections around the eyes and in the face include temporary bruising, eyelid drooping (ptosis), dry eyes, and double vision (diplopia) (Hsiung 2002; Tan 2002), and facial droop can occur with injections into the cheek. It is generally agreed that in the hands of experienced physicians, these side effects are considered rare.

The most common side effects in patients receiving Botox® for cervical dystonia are difficulty swallowing (dysphagia), upper respiratory infection, neck pain, and headache. Potential complications when using Botox® in the face and neck occur when too much toxin is injected or when the right amount is injected into the wrong muscle. Inaccurate injections in the forehead or around the eyes can cause drooping lids; too much injected in the neck can cause muscle weakness and difficulty swallowing. In general, when used at recommended doses by skilled physicians, Botox® is safe and is not known to cause any long-term side effects.

What long-term clinical data exist show a medication with a good record of safety. In a study of 65 patients who received repeated injections for 10 years, side effects were all temporary and mild and decreased after repeated injections (Defazio 2002). Examination of the eye muscles after Botox® has shown that repeated injections do not cause irreversible muscle atrophy (wasting) or any other degenerative changes (Borodic 1992), and muscle function after injection reverts to normal (de Paiva 1999). A large study of 235 patients who received Botox® injections for cervical dystonia, hemifacial spasm, and blepharospasm showed a 75% benefit from treatment for up to 10 years. Although side effects occurred in 27% of study participants at any one time, only 1.3% stopped receiving injections because of intolerable adverse effects (Hsiung 2002).

What does this tell you?

Botox® injections have not been shown to permanently change your muscles or cause any long-term problems. The side effects of Botox® injections are usually exactly what the therapy is supposed to cause: muscle weakness. It's crucial to inject into the right muscle with the appropriate dose. Finding an experienced physician is of utmost importance, as many complications are the result of misplaced injections or too-large doses.

Related Articles

  More Botox® Articles...