Medically reviewed on July 3, 2018
What is onabotulinumtoxinA (Botox)?
OnabotulinumtoxinA (Botox), is made from the bacteria that causes botulism. Botulinum toxin blocks nerve activity in the muscles.
Botox is used in adults to treat cervical dystonia (severe spasms in the neck muscles), or muscle stiffness in the elbows, wrists, fingers, ankles, or toes. Botox is also used to treat severe underarm sweating (hyperhidrosis).
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 is also used to treat certain eye muscle conditions caused by nerve disorders in adults and children who are at least 12 years old. This includes uncontrolled blinking or spasm of the eyelids, and a condition in which the eyes do not point in the same direction.
Botox Cosmetic is used to temporarily lessen the appearance of facial wrinkles in adults.
Botox may also be used for purposes not listed in this medication guide.
The botulinum toxin contained in onabotulinumtoxinA can spread to other body areas beyond where it was injected. This can cause serious life-threatening side effects.
Call your doctor at once if you have a hoarse voice, drooping eyelids, vision problems, severe eye irritation, severe muscle weakness, loss of bladder control, or trouble breathing, talking, or swallowing.
Before taking this medicine
You should not be treated with Botox if you are allergic to botulinum toxin, or if you have:
an infection in the area where the medicine will be injected; or
(for overactive bladder and incontinence) if you have a current bladder infection or if you are unable to urinate and you do not routinely use a catheter.
Tell your doctor if you have ever had:
a side effect after prior use of botulinum toxin;
problems with swallowing;
facial muscle weakness (droopy eyelids, weak forehead, trouble raising your eyebrows);
a change in the normal appearance of your face;
heart disease; or
surgery (especially on your face).
Botox is made from donated human plasma and may contain viruses or other infectious agents. Donated plasma is tested and treated to reduce the risk of contamination, but there is still a small possibility it could transmit disease. Ask your doctor about any possible risk.
It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.
It may not be safe to breast-feed while using this medicine. Ask your doctor about any risk.
How is Botox given?
Botox injections should be given only by a trained medical professional, even when used for cosmetic purposes.
onabotulinumtoxinA is injected into a muscle by a healthcare provider. Botox injections should be spaced at least 3 months apart.
Botox injections may be given into more than one area at a time, depending on the condition being treated.
While receiving injections for eye muscle conditions, you may need to use eye drops, ointment, a special contact lens or other device to protect the surface of your eye. Follow your doctor's instructions.
If you are being treated for excessive sweating, shave your underarms about 24 hours before your injection. Do not apply antiperspirant or deodorant for 24 hours before or after you receive the injection. Avoid exercise and hot foods or beverages within 30 minutes before the injection.
It may take up to 2 weeks after injection before neck muscle spasm symptoms begin to improve. You may notice the greatest improvement after 6 weeks.
It may take only 1 to 3 days after injection before eye muscle spasm symptoms begin to improve. You may notice the greatest improvement after 2 to 6 weeks.
The effects of a Botox injection are temporary. Your symptoms may return completely within 3 months. After repeat injections, it may take less and less time before your symptoms return, especially if your body develops antibodies to the botulinum toxin.
Do not seek botulinum toxin injections from more than one medical professional at a time. If you switch healthcare providers, tell your new provider how long it has been since your last botulinum toxin injection.
Using this medication more often than prescribed will not make it more effective and may result in serious side effects.
What happens if I miss a dose?
Since botulinum toxin has a temporary effect and is given at widely spaced intervals, missing a dose is not likely to be harmful.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
Overdose symptoms may not appear right away, but can include muscle weakness, trouble swallowing, and weak or shallow breathing.
What should I avoid after receiving Botox?
Botox may impair your vision or depth perception. Avoid driving or hazardous activity until you know how onabotulinumtoxinA will affect you.
Avoid going back to your normal physical activities too quickly after receiving an injection.
Botox side effects
Get emergency medical help if you have signs of an allergic reaction: hives, itching; wheezing, difficult 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 botulinum toxin injections, even for cosmetic purposes.
Call your doctor at once if you have any of these side effects (up to several hours or several weeks after an injection):
unusual or severe muscle weakness (especially in a body area that was not injected with the medication);
trouble breathing, talking, or swallowing;
loss of bladder control;
hoarse voice, drooping eyelids;
vision changes, eye pain, severely dry or irritated eyes (your eyes may also be more sensitive to light);
chest pain or pressure, pain spreading to your jaw or shoulder, irregular heartbeats;
pain or burning when you urinate, trouble emptying your bladder;
sore throat, cough, chest tightness, shortness of breath; or
eyelid swelling, crusting or drainage from your eyes, problems with vision.
Common side effects may include:
muscle weakness near where the medicine was injected;
trouble swallowing for several months after treatment;
muscle stiffness, neck pain, pain in your arms or legs;
blurred vision, puffy eyelids, dry eyes, drooping eyebrows;
increased sweating in areas other than the underarms; or
bruising, bleeding, pain, redness, or swelling where the injection was given.
This is not a complete list of 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.
See also: Side effects (in more detail)
What other drugs will affect Botox?
Tell your doctor about all your other medicines, especially:
a muscle relaxer;
cold or allergy medicine;
an injectable antibiotic; or
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
Copyright 1996-2018 Cerner Multum, Inc. Version: 6.01.
More about onabotulinumtoxinA
- OnabotulinumtoxinA Side Effects
- During Pregnancy
- Dosage Information
- Drug Interactions
- En Español
- 265 Reviews
- Drug class: skeletal muscle relaxants
- OnabotulinumtoxinA Cosmetic Injection
- OnabotulinumtoxinA Injection
- Onabotulinumtoxina Intramuscular (Advanced Reading)