Botox (onabotulinumtoxinA), also called botulinum toxin type A, is made from the bacteria that causes botulism. Botulinum toxin blocks nerve activity in the muscles, causing a temporary reduction in muscle activity.
Botox is used to treat cervical dystonia (severe spasms in the neck muscles), muscle spasms in the arms and hands, severe underarm sweating (hyperhidrosis), urinary incontinence in people with neurologic conditions and to prevent headaches in adult patients with chronic migraine.
Botox is also used to treat certain eye muscle conditions caused by nerve disorders. This includes uncontrolled blinking or spasm of the eyelids, and a condition in which the eyes do not point in the same direction.
Botox is also used to treat overactive bladder and incontinence (urine leakage) caused by nerve disorders such as spinal cord injury or multiple sclerosis.
Botox is also used to prevent chronic migraine headaches in adults who have migraines for more than 15 days per month, each lasting 4 hours or longer. Botox should not be used to treat a common tension headache.
Botox Cosmetic is used to temporarily lessen the appearance of facial wrinkles.
Get emergency medical help if you have any of these signs of an allergic reaction to Botox: hives; difficulty breathing; feeling like you might pass out; swelling of your face, lips, tongue, or throat.
The botulinum toxin contained in Botox can spread to other body areas beyond where it was injected. This has caused serious life-threatening side effects in some people receiving botulism toxin injections, even for cosmetic purposes.
Call your doctor at once if you have any of these serious side effects, some of which can occur up to several weeks after an injection:
- trouble breathing, talking, or swallowing;
- hoarse voice, drooping eyelids;
- unusual or severe muscle weakness (especially in a body area that was not injected with the medication);
- loss of bladder control;
- problems with vision;
- crusting or drainage from your eyes;
- severe skin rash or itching;
- fast, slow, or uneven heartbeats; or
- chest pain or heavy feeling, pain spreading to the arm or shoulder, general ill feeling.
Less serious Botox side effects may include:
- muscle weakness near where the medicine was injected;
- bruising, bleeding, pain, redness, or swelling where the injection was given;
- headache, muscle stiffness, neck or back pain;
- fever, cough, sore throat, runny nose, flu symptoms,
- dizziness, drowsiness, tired feeling;
- nausea, diarrhea, stomach pain, loss of appetite;
- dry mouth, dry eyes, ringing in your ears;
- increased sweating in areas other than the underarms;
- itchy or watery eyes, increased sensitivity to light; or
- eyelid swelling or bruising.
This is not a complete list of Botox side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.