Pronunciation: on-a-bot-u-line-um tox-in A
Generic name: OnabotulinumtoxinA
Brand names: Botox, Botox Cosmetic
Dosage form: vial, single-use
Drug class: Skeletal muscle relaxants

Medically reviewed by Carmen Pope, BPharm. Last updated on Oct 30, 2024.

What is onabotulinumtoxinA?

OnabotulinumtoxinA is an injectable botulinum toxin type A preparation that may be used for certain medical conditions or to improve appearance. There are 2 different formulations of onabotulinumtoxinA: Botox and Botox Cosmetic. Each contains the same active ingredient (onabotulinumtoxinA) but the number of dosage units per vial and FDA-approved uses differ, and they are not interchangeable.

Botox is FDA-approved to treat certain medical conditions, specifically:

• Overactive bladder (OAB) in adults; urinary incontinence due to detrusor muscle overactivity associated with a neurologic condition (such as a spinal cord injury or multiple sclerosis) in adults; or neurogenic detrusor overactivity (NDO) in children aged 5 years of age and older
  • Botox is only used for these conditions in those who have already tried an anticholinergic medication but have had an inadequate response to or are intolerant of it
  • The detrusor muscle sits at the opening of the bladder and contracts to push urine from the bladder to the urethra.
• Spasticity in patients aged 2 years of age and older
• Cervical dystonia (abnormal neck muscle contraction) in adults and adolescents over the age of 16, to reduce the severity of abnormal head position and neck pain
• Excessive armpit sweating (severe axillary hyperhidrosis) that is inadequately managed by topical antiperspirants in adults
• Blepharospasms (eyelid spasms) associated with dystonia (jaw clenching, involuntary facial or tongue movements) in patients aged 12 years and older
• Strabismus (crossed eyes) in patients 12 years of age and older.

Botox is also approved to prevent headaches in adults with chronic migraine (at least 15 headache days per month) whose headaches last 4 hours a day or longer.

Botox Cosmetic is FDA-approved for the temporary improvement in the appearance of:

• Moderate to severe frown lines (glabellar lines)
• Severe outer eye wrinkles (crow’s feet also called lateral canthal lines)
• Moderate to severe forehead lines.
• Vertical bands connecting the jaw and neck (platysma bands)

You may receive treatment for frown lines, crow’s feet lines, and forehead lines at the same time.

OnabotulinumtoxinA is a neurotoxin that works by blocking the release of a neurotransmitter called acetylcholine, which prevents muscle contraction in the area injected, causing the muscles to relax. In small, localized doses, this can treat a range of medical conditions, such as muscle spasms, detrusor muscle contraction, and excessive sweat gland activity, as well as reduce skin wrinkles. The effect is only temporary because extra nerve endings and acetylcholine receptors develop.

Botox and Botox Cosmetic were first FDA-approved on December 9, 1991.

What are the side effects of onabotulinumtoxinA?

OnabotulinumtoxinA (Botox/Botox Cosmetic) may cause serious side effects, see warnings below.

Get emergency medical help if you have signs of an allergic reaction: hives, itching; wheezing, difficulty breathing; feeling like you might pass out; swelling of your face, lips, tongue, or throat.

Other side effects may include:

• dry mouth
• discomfort or pain at the injection site
• tiredness
• headache
• neck pain
• eye problems: double vision, blurred vision, decreased eyesight, drooping eyelids, swelling of your eyelids, dry eyes
• drooping eyebrows
• urinary tract infection in both children and adults being treated for urinary incontinence
• painful urination in adults being treated for urinary incontinence
• bacteria, white blood cells, and blood in the urine of children being treated for urinary incontinence
• inability to empty your bladder on your own and are being treated for urinary incontinence. If you have difficulty fully emptying your bladder after getting Botox, you may need to use disposable self-catheters to empty your bladder up to a few times each day until your bladder can start emptying again
• upper respiratory tract infection.

Tell your doctor if you have any side effect that bothers you or that does not go away. These are not all the possible side effects of onabotulinumtoxinA (Botox/Botox Cosmetic). For more information, ask your doctor or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA1088.

Related/similar drugs

Warnings and serious effects

OnabotulinumtoxinA may cause serious side effects that can be life-threatening. These problems can happen hours, days, to weeks after an injection of Botox or Botox Cosmetic. Call your doctor or get medical help right away if you have any of these problems after treatment:

• Problems swallowing, speaking, or breathing. These problems can happen hours, days, to weeks after an injection of Botox or Botox Cosmetic if it has affected the muscles that you use to breathe and swallow, and can be potentially fatal. People with certain breathing or swallowing problems may be at greater risk.
• Spread of toxin effects. In some cases, the effect of botulinum toxin may affect areas of the body away from the injection site and cause symptoms of a serious condition called botulism. The symptoms of botulism include:
  • loss of strength and muscle weakness all over the body
  • double vision, blurred vision, and drooping eyelids
  • hoarseness or change or loss of voice (dysphonia)
  • trouble saying words clearly (dysarthria)
  • loss of bladder control
  • trouble breathing
  • trouble swallowing.

Seek immediate medical attention if respiratory, speech, or swallowing difficulties occur.

Due to different potency units, Botox and Botox Cosmetic are not interchangeable with other botulinum toxin products, such as Myobloc, Dysport, Xeomin, Daxxify, Letybo, or Jeuveau.

Botox and Botox Cosmetic must be administered by a trained healthcare provider and only for FDA-approved indications. Potential serious side effects may occur with unapproved uses.

People with preexisting neuromuscular disorders or compromised respiratory function may be more at risk of side effects. When used to treat blepharospasm, corneal exposure and ulceration due to reduced blinking may occur with Botox treatment. Eye and retinal problems may also occur. Your healthcare provider will monitor you for these.

You should not receive 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).

It is not known whether Botox is safe and effective in people younger than:

• 18 years when used to treat OAB with urinary incontinence, excessive sweating, or prevent chronic migraine
• 16 years when used to treat cervical dystonia
• 12 years when used to treat strabismus or blepharospasm
• 5 years when used to treat OAB due to a neurologic disease
• 2 years when used to treat spasticity.

It is not known whether Botox is safe and effective in preventing headaches in people who have less than 14 headache days each month (episodic migraine) or for severe sweating anywhere other than the armpits.

It is not known whether Botox Cosmetic is safe and effective in people younger than 18 years of age or for use more than once every 3 months.

Before taking

Do not receive onabotulinumtoxinA (Botox/Botox Cosmetic):

• if you are allergic to or have had side effects from onabotulinumtoxinA, Botox, Botox Cosmetic, any of the inactive ingredients in the Botox products, or any other botulinum toxin product such as Myobloc, Dysport, Xeomin, Daxxify, Letybo, or Jeuveau.
• have a skin infection at the planned injection site
• are being treated for urinary incontinence and have a urinary tract infection (UTI)
• are being treated for urinary incontinence and find that you cannot empty your bladder on your own (only applies to people who are not routinely catheterizing).

Tell your doctor about all your medical conditions, including if you:

• have a disease that affects your muscles and nerves, such as amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease), myasthenia gravis, or Lambert-Eaton syndrome
• have or have had a breathing problem, such as asthma or emphysema
• have or have had swallowing problems
• have or have had bleeding problems
• have plans to have surgery or have had surgery on your face
• have weakness of your forehead muscles, such as trouble raising your eyebrows
• have drooping eyelids
• have any other change in the way your face normally looks
• have symptoms of a urinary tract infection (UTI) and are being treated for urinary incontinence Symptoms of a urinary tract infection may include pain or burning with urination, frequent urination, or fever
• have problems emptying your bladder on your own and are being treated for urinary incontinence
• are pregnant or plan to become pregnant
• are breastfeeding or plan to breastfeed.

Pregnancy

Based on animal data, onabotulinumtoxinA (Botox/Botox Cosmetic) may harm your unborn baby. Talk to your healthcare provider about the risks involved with receiving onabotulinumtoxinA during pregnancy.

Breastfeeding

It is not known if onabotulinumtoxinA (Botox/Botox Cosmetic) passes into breast milk. Talk to your healthcare provider about the best way to feed your baby.

How is onabotulinumtoxinA (Botox/Botox Cosmetic) administered?

OnabotulinumtoxinA (Botox/Botox Cosmetic) injections should be given only by a trained medical professional, even when used for cosmetic purposes.

• Botox is injected into your affected muscles, skin, or bladder.
• Botox Cosmetic is injected into the specific muscles on your face that contribute to severe wrinkles or facial lines.

Your healthcare provider may change your dose until the best dose for you is found.

• Your healthcare provider will tell you how often you will receive your injection of Botox. Botox Cosmetic injections should be spaced at least 3 months apart.

The effects of an onabotulinumtoxinA 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.

Other dosage information

Injections may be given into more than one area at a time, depending on the condition.

While receiving injections for eye muscle conditions, you may need to use eye drops, ointment, a special contact lens, or another device to protect the surface of your eye. Follow your doctor's instructions.

• 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.

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.

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.

What happens if I miss a dose?

Since onabotulinumtoxinA (Botox/Botox Cosmetic) 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.

Using this medication more often than prescribed will not make it more effective and may result in serious side effects.

What should I avoid after receiving onabotulinumtoxinA?

OnabotulinumtoxinA may cause loss of strength or general muscle weakness, vision problems, or dizziness within hours to weeks of receiving Botox or Botox Cosmetic. If this happens, do not drive a car, operate machinery, or do other dangerous activities.

Avoid going back to your normal physical activities too quickly after receiving an injection.

What other drugs will affect onabotulinumtoxinA?

Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Using onabotulinumtoxinA with certain other medicines may cause serious side effects. Do not start any new medicines until you have told your doctor that you have received onabotulinumtoxinA in the past. Especially tell your doctor if you:

• have received any other botulinum toxin product in the last four months
• have received injections of botulinum toxin, such as Myobloc® (rimabotulinumtoxinB), Dysport® (abobotulinumtoxinA), or Xeomin® (incobotulinumtoxinA) in the past. Be sure your doctor knows exactly which product you received
• have recently received an antibiotic by injection
• take muscle relaxants
• take an allergy or cold medicine
• take a sleep medicine
• take anti-platelets (aspirin-like products) or anti-coagulants (blood thinners).

Ask your doctor if you are not sure if your medicine is listed above. Know the medicines you take. Keep a list of your medicines with you to show your doctor and pharmacist each time you get a new medicine. This list is not complete. Other drugs may affect onabotulinumtoxinA, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Storage

Unopened vials of Botox and Botox Cosmetic should be stored in a refrigerator between 2° to 8°C (36º to 46ºF). Do not use after the expiration date on the vial.

Reconstituted Botox/Botox Cosmetic may be stored in a refrigerator (2° to 8°C) for up to 24 hours until the time of use.

Ingredients

Active ingredient: onabotulinumtoxinA

Inactive ingredients: human albumin and sodium chloride.

• Botox for injection is a sterile, dried powder supplied in a single-dose vial in 100 and 200 Units.
• Botox Cosmetic for injection is a dried powder supplied in a single-dose vial in 50 and 100 Units.

Cartons have features to alert users if content may have been compromised, for example, each Botox and Botox Cosmetic vial label and carton labeling also contain the U.S. License number 1889. Do not use the product and contact AbbVie for additional information at 1-800-678-1605 if the labeling is not as described above.

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 your risk.

Manufacturer

AbbVie Inc.

Onabotulinumtoxina Biosimilars

Biosimilar and interchangeable products are biological products that are highly similar to and have no clinically meaningful differences from the reference product.

Reference products

These are biological products that have already been approved by the FDA, against which biosimilar products are compared. There are 2 for onabotulinumtoxinA.

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