OnabotulinumtoxinA
Pronunciation: (oh-na-boh-tyoo-lih-num-tox-in AY).
- Generic name
- onabotulinumtoxinA
- Brand names
- Botogen, Botox, Botox Cosmetic, Botox-A, Vistabel
- Drug class
- Neuromuscular Blocker (Botulinum Toxin Type A)
Availability and supply rules vary by country
Trade names by country: Canada
Australia: · Full directory
What onabotulinumtoxinA is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how onabotulinumtoxinA works
OnabotulinumtoxinA is a neurotoxin that inhibits acetylcholine release at the neuromuscular junction, resulting in temporary muscle paralysis or reduced glandular activity. This blockade is achieved by cleaving SNAP-25, a protein essential for synaptic vesicle fusion and neurotransmitter release. (1)
What onabotulinumtoxinA is used for
Chronic migraines
Chronic migraines (2)
Muscle spasticity
Muscle spasticity (2)
Cosmetic procedures
Cosmetic procedures (2)
Overactive bladder with urge incontinence in adults inadequately managed with anticholinergic medicines
FDA-approved indication; also approved for urinary incontinence due to detrusor overactivity from a neurologic condition. (2)
Severe primary axillary hyperhidrosis inadequately managed with topical treatment
Severe primary axillary hyperhidrosis inadequately managed with topical treatment (2)
Before taking onabotulinumtoxinA
Do not take / not appropriate for
- hypersensitivity to botulinum toxin or formulation components, and infection at the injection site. (Contraindication) (2)
- Caution is also advised in elderly or debilitated patients. (Contraindication) (2)
Tell your clinician about
(2)How to take onabotulinumtoxinA
- General Instructions: Botox is only administered by trained healthcare professionals. Do not attempt to inject this medication yourself.. Adult Dosing: Dosing varies by indication and muscle group. For chronic migraine, typical dose is 155 units divided across 31 sites every 12 weeks. For cosmetic use, doses are lower and targeted to specific facial muscles. Always follow your provider’s instructions.. Pediatric Dosing: Approved for certain pediatric conditions (e.g., spasticity in children ≥2 years). Dosing is weight-based and determined by the specialist.. Administration: Injected directly into the affected muscle, gland, or area by a healthcare provider. The procedure is usually performed in a clinic or hospital setting.. When To Stop: Treatment is discontinued if there is hypersensitivity, severe adverse reaction, or lack of efficacy. Always consult your provider before stopping.. Storage: Unreconstituted vials should be stored in a refrigerator (2–8°C). After reconstitution, use within 24 hours and store in a refrigerator.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (2)
Missed dose
If you miss an appointment for your Botox injection, contact your healthcare provider to reschedule. Do not attempt to self-administer or double up on doses.
Overdose
Symptoms of overdose may include generalized muscle weakness, difficulty breathing, or swallowing. Seek emergency medical attention immediately. Hospitalization and supportive care may be required. (2)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Pain at injection site
Incidence: Reported in the clinician-authored database; frequency not established
Headache
Incidence: Reported in the clinician-authored database; frequency not established
Flu-like symptoms
Incidence: Reported in the clinician-authored database; frequency not established
Muscle weakness (generalized)
Incidence: Reported in the clinician-authored database; frequency not established
Drooping eyelids
Incidence: Reported in the clinician-authored database; frequency not established
Difficulty swallowing (dysphagia)
Incidence: Reported in the clinician-authored database; frequency not established
Breathing difficulties
Incidence: Reported in the clinician-authored database; frequency not established
Serious warnings
FDA BOXED WARNING (distant spread of toxin effect) — serious
Symptoms: FDA BOXED WARNING (distant spread of toxin effect): The effects of Botox and all botulinum toxin products may spread from the area of injection to produce symptoms consistent with botulinum toxin effects — including generalized weakness, double vision, drooping eyelids, difficulty swallowing, difficulty speaking, loss of bladder control, and breathing difficulties — reported hours to weeks after injection. Swallowing and breathing difficulties can be life-threatening, and deaths have been reported. The risk appears greatest in children treated for spasticity, but can also occur in adults, particularly those with an underlying condition that predisposes them to these symptoms.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Botox can spread from the injection site and cause symptoms of botulism — serious
Symptoms: Botox can spread from the injection site and cause symptoms of botulism. Serious swallowing or breathing difficulties may occur. Not recommended during pregnancy or breastfeeding unless clearly needed. Use caution in patients with neuromuscular disorders. May interact with certain medications, increasing risk of side effects.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Serious and/or immediate hypersensitivity reactions have been reported, including anaphylaxis, serum sickness, urticaria, soft-tissue edema, and dyspnea — serious
Symptoms: Serious and/or immediate hypersensitivity reactions have been reported, including anaphylaxis, serum sickness, urticaria, soft-tissue edema, and dyspnea. If signs of a reaction occur, seek emergency medical care immediately; your treating clinician will decide whether further injections are appropriate.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Contraindications recorded in the clinician database — serious
Symptoms: Contraindications recorded in the clinician database: Contraindications include hypersensitivity to botulinum toxin or formulation components, and infection at the injection site. Use with caution in patients with neuromuscular disorders (e.g., myasthenia gravis, ALS), respiratory compromise, or swallowing difficulties. Caution is also advised in elderly or debilitated patients.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Recorded interactions | Botox may interact with aminoglycoside antibiotics, muscle relaxants, anticholinergic drugs, and other agents affecting neuromuscular transmission, potentially increasing the risk of excessive muscle weakness or respiratory compromise. Always inform your healthcare provider of all medications and supplements you are taking. | (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
The FDA label states that, based on animal data, Botox may cause fetal harm. There are no adequate and well-controlled studies of Botox in pregnant women; animal studies at clinically relevant doses showed adverse effects on fetal growth associated with maternal toxicity. Botox should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus — discuss with the prescribing clinician. (2)
Breastfeeding
The FDA label states there are no data on the presence of Botox (onabotulinumtoxinA) in human milk, its effects on the breastfed infant, or its effects on milk production. The developmental and health benefits of breastfeeding should be weighed against the mother's clinical need for Botox and any potential adverse effects on the breastfed child — discuss with the prescribing clinician. (2)
Children
Frequency: Not applicable as pediatric use is not established.. Weight Based: Not recommended for pediatric use.. Max Daily Dose: Not applicable as pediatric use is not established.. Max Single Dose: Not applicable as pediatric use is not established.. Age Restrictions: Safety not established in children. (2)
Renal_impairment
The FDA prescribing information does not provide specific dose-adjustment guidance for renal or hepatic impairment, and no dedicated renal- or hepatic-impairment studies are described in the label. Renal and hepatic status should be assessed by the treating clinician when planning treatment. (2)
Hepatic_impairment
The FDA prescribing information does not provide specific dose-adjustment guidance for renal or hepatic impairment, and no dedicated renal- or hepatic-impairment studies are described in the label. Renal and hepatic status should be assessed by the treating clinician when planning treatment. (2)
Monitoring
(2)Storage
Store unopened Botox vials in a refrigerator at 2°C to 8°C (36°F to 46°F). After reconstitution with preservative-free 0.9% sodium chloride injection, store the reconstituted solution in a refrigerator (2°C to 8°C) and use within 24 hours; do not freeze reconstituted Botox. Vials are for single-dose use only — discard any unused portion.
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General
Indication: Chronic migraines
Dose summary: For chronic migraines, the recommended dose is 155 units administered in 5 sites around the head and neck every 12 weeks.
Renal context: The FDA prescribing information does not provide specific dose-adjustment guidance for renal impairment; no dedicated renal-impairment dosing studies are described in the label. Renal function should be assessed by the treating clinician when determining the injection plan. (1) (2)
Hepatic guidance
The FDA prescribing information does not provide specific dose-adjustment guidance for hepatic impairment; no dedicated hepatic-impairment dosing studies are described in the label. Hepatic status should be assessed by the treating clinician when determining the injection plan.
Frequently asked questions
How long does Botox last?
The effects of Botox typically last 3 to 6 months, depending on the condition treated and individual response. Repeat treatments are usually needed to maintain results.
Is Botox safe for long-term use?
When administered by a qualified healthcare professional, Botox is considered safe for long-term use in approved indications. Regular monitoring and follow-up are recommended.
Can I get Botox while pregnant or breastfeeding?
Botox is not recommended during pregnancy or breastfeeding due to limited safety data. Discuss risks and benefits with your healthcare provider.
What should I do if I experience side effects after Botox?
Contact your healthcare provider if you experience any side effects. Seek emergency care if you have difficulty breathing, swallowing, or develop severe muscle weakness.
Can Botox be used for migraines?
Yes, Botox is FDA-approved for the prevention of chronic migraine in adults who experience 15 or more headache days per month.
How soon will I see results after a Botox injection?
Results are usually seen within 3 to 7 days after injection, with maximum effect at about 2 weeks.
Are there any foods or activities I should avoid after Botox?
Avoid massaging or rubbing the treated area, strenuous exercise, and lying down for several hours after the injection to prevent unwanted spread of the toxin.
What happens if I take too much Botox (onabotulinumtoxinA)?
An overdose of Botox (onabotulinumtoxinA) can lead to severe muscle weakness, difficulty breathing, swallowing problems, and vision disturbances due to the widespread effect of the toxin. These symptoms can be life-threatening. If you suspect an overdose, seek immediate emergency medical attention. Do not attempt to self-treat or wait for symptoms to worsen.
Can I drink alcohol while taking Botox (onabotulinumtoxinA)?
While there isn't a direct interaction between alcohol and Botox (onabotulinumtoxinA) that would diminish its therapeutic effect, alcohol can increase bruising at the injection site. It's generally advisable to avoid alcohol for at least 24 hours before and after your Botox treatment to minimize this risk. Always discuss alcohol consumption with your healthcare provider.
Is Botox (onabotulinumtoxinA) safe during pregnancy?
Current FDA labeling no longer uses the old pregnancy letter categories (so Botox is not labeled "Category C"); instead it states that, based on animal data, Botox may cause fetal harm, and there are no adequate human studies. Animal studies at clinically relevant doses showed adverse effects on fetal growth associated with maternal toxicity. Always consult your doctor if you are pregnant or planning to become pregnant before receiving Botox.
What is the mechanism of action of onabotulinumtoxinA?
OnabotulinumtoxinA is a neurotoxin that inhibits acetylcholine release at the neuromuscular junction, resulting in temporary muscle paralysis or reduced glandular activity. This blockade is achieved by cleaving SNAP-25, a protein essential for synaptic vesicle fusion and neurotransmitter release. (1)
What is the generic name of OnabotulinumtoxinA?
The generic name is onabotulinumtoxinA. It is sold under brand names including Botogen, Botox, Botox Cosmetic, Botox-A, Vistabel.
What class of drug is onabotulinumtoxinA?
OnabotulinumtoxinA is classed as: Neuromuscular Blocker (Botulinum Toxin Type A).
References
- MedGuideGlobal clinician-authored medicine record for Botox (onabotulinumtoxinA)MedGuideGlobal · Global · accessed 2026-08-06 · source 1
- BOTOX (onabotulinumtoxinA) for injection, for intramuscular, intradetrusor, or intradermal use – full prescribing informationU.S. Food and Drug Administration · United States · accessed 2026-08-06 · source 2
- BOTOX (ONABOTULINUMTOXINA) INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION [ALLERGAN, INC.] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
- BOTOX — FDA approval record (Drugs@FDA BLA103000)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 4
- onabotulinumtoxinA — RxNorm normalized drug concept (RXCUI 860189)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 5
Brand names by country
Single-ingredient onabotulinumtoxinA names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
Canada
- BOTOX
- BOTOX COSMETIC