Jul 19, 2022

Generic name:  onabotulinumtoxinA  [ ON-a-BOT-ue-LYE-num-TOX-in-A ]
Brand names: Botox, Botox Cosmetic
Drug class:  Skeletal muscle relaxants

What is Botox?

Botox injections are used to soften facial wrinkles, to prevent chronic migraines, excessive sweating, cervical dystonia, spasticity, some eye muscle conditions and treat urinary leakage caused by an overactive bladder. Botox injections work by relaxing muscles by blocking signals that make muscles contract.

Botox is made from the bacteria that causes  botulism . Botulinum toxin blocks nerve activity in the muscles.

What is Botox used for?

Chronic migraine: Botox is used for chronic migraines in patients who have 15 or more headaches a month that last for 4 hours a day or longer.
For migraines botox is given into seven specific areas of the head and neck muscles. Results usually  last up to 12 weeks depending on the individual patient.

Facial wrinkles: Botox Cosmetic is used to temporarily lessen the appearance of  facial wrinkles  in adults.

Cervical dystonia: Botox is used in adults to treat  cervical dystonia  which is a condition that causes your neck muscles to contract abnormally. This makes your neck twist and causes your head to tilt to one side, forward, or backward.

Muscle stiffness: Botox is also used to treat muscle stiffness (spasticity) of the arms, hands, legs, and feet in adults and children who are at least 2 years old. Spasticity is when there is an abnormal increase in muscle tone or stiffness of muscle, which can cause problems with movement, speech, or can cause discomfort or pain.

Eye muscle conditions: Botox is 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 ( strabismus ).

Bladder issues: Botox is used in adults to treat  overactive bladder  and  incontinence  (urine leakage) that has not been helped by other medication. Botox may be used to treat incontinence caused by nerve disorders such as spinal cord injury or multiple sclerosis.
Botox is also used to treat overactive bladder due to a neurologic disease (such as multiple sclerosis or spinal cord injury) in children 5 years of age and older when another type of medicine (anticholinergic) does not work well enough or cannot be taken.

Excessive sweating: Botox is also used to treat severe underarm sweating (hyperhidrosis) in adults.


You should not use Botox if you have an infection in the area where the medicine will be injected. This medicine should not be used to treat overactive bladder or incontinence if you have a current bladder infection or if you are unable to urinate (unless you routinely use a catheter).

The botulinum toxin contained in Botox 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.

To make sure Botox is safe for you, tell your doctor if you have ever had:

  • other botulinum toxin injections such as  Dysport  or  Myobloc  (especially in the last 4 months);
  • amyotrophic lateral sclerosis  (ALS, or ” Lou Gehrig’s disease “);
  • myasthenia gravis ;
  • Lambert-Eaton syndrome;
  • a side effect after prior use of botulinum toxin;
  • a breathing disorder such as  asthma  or  emphysema ;
  • problems with swallowing;
  • facial muscle weakness (droopy eyelids, weak forehead, trouble raising your eyebrows);
  • a change in the normal appearance of your face;
  • bleeding problems; 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 breastfeed 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.

This medicine 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.

Detailed Botox dosage information

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 this medicine 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 to Botox:  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);
  • loss of bladder control;
  • hoarse voice, trouble talking or swallowing;
  • drooping eyelids or eyebrows;
  • 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 Botox side effects may include:

  • painful or difficult urination;
  • headache, neck pain, back pain, pain in your arms or legs;
  • cold symptoms such as stuffy nose, sneezing, sore throat;
  • trouble swallowing;
  • fever, chills, body aches, flu symptoms;
  • 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.

Botox side effects  (more detail)

What other drugs will affect Botox?

Tell your doctor about all your other medicines, especially:

  • a muscle relaxer;
  • cold or allergy medicine;
  • sleep medicine;
  • an injectable  antibiotic ; or
  • a blood thinner –  warfarin ,  Coumadin ,  Jantoven .

This list is not complete. Other drugs may affect Botox, including prescription and over-the-counter medicines,  vitamins , and  herbal products . Not all possible drug interactions are listed here.

Botox drug interactions  (more detail)

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