Skip to main content

IncobotulinumtoxinA Side Effects

Medically reviewed by Last updated on Aug 3, 2023.

Applies to incobotulinumtoxinA: powder for solution.


Intramuscular route (Powder for Solution)

Distant Spread of Toxin EffectThe effects of incobotulinumtoxinA and all botulinum toxin products may spread from the area of injection to produce symptoms consistent with botulinum toxin effects. These symptoms have been reported hours to weeks after injection. Swallowing and breathing difficulties can be life threatening and there have been reports of death. The risk of symptoms is probably greatest in children treated for spasticity, but symptoms can also occur in adults, particularly in those patients who have underlying conditions that would predispose them to these symptoms.

Serious side effects of IncobotulinumtoxinA

Along with its needed effects, incobotulinumtoxinA may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking incobotulinumtoxinA:

More common—for blepharospasm

More common—for cervical dystonia

Less common—for blepharospasm

Less common—for sialorrhea

Less common—for upper limb spasticity

Rare—for glabellar lines

Incidence not known

Other side effects of IncobotulinumtoxinA

Some side effects of incobotulinumtoxinA may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common—for blepharospasm

Less common—for sialorrhea

Less common—for upper limb spasticity

Rare—for glabellar lines

Incidence not known

For Healthcare Professionals

Applies to incobotulinumtoxinA: intramuscular powder for injection.


The frequency of adverse reactions varies based on usage. The more frequently reported adverse events in the chronic sialorrhea trials included tooth extraction, dry mouth, diarrhea, and hypertension; in the upper limb spasticity trials, seizure, nasopharyngitis, dry mouth, and upper respiratory tract infection; in the cervical dystonia trials, dysphagia, neck pain, and muscle weakness; for blepharospasm, eyelid ptosis, dry eye, and dry mouth; and for treating glabellar lines, the most frequently reported adverse event was headache.


Common (1% to 10%): Injection site pain, injection site hematoma

Very rare (less than 0.01%): Spread of toxin

Frequency not reported: Injection site reaction, allergic dermatitis, localized allergic reactions (e.g., welling, edema, erythema, pruritus, rash), herpes zoster[Ref]


Common (1% to 10%): Asthma, nasopharyngitis, respiratory tract infection, dyspnea, bronchitis[Ref]


Postmarketing reports: Localized allergic reactions, hypersensitivity, allergic dermatitis[Ref]

Hypersensitivity reactions including anaphylaxis, serum sickness, urticaria, soft tissue edema, and dyspnea have been reported with botulinum toxin products. Localized allergic reactions reported during the postmarketing period with this drug include swelling, edema, erythema, pruritus, or rash.[Ref]


Common (1% to 10%): Dry eye (19%), eyelid ptosis (19%)

Uncommon (0.1% to 1%): Impaired vision, blurred vision, lacrimation increased, eye swelling, eyelid edema, diplopia[Ref]


Very common (10% or more): Neck pain (up to 16%), muscular weakness (up to 14%)

Common (1% to 10%): Musculoskeletal pain, muscle spasms, musculoskeletal stiffness, back pain

Uncommon (0.1% to 1%): Pain in extremity, muscular weakness, dysarthria, myalgia[Ref]

Nervous system

Common (1% to 10%): Headache, dizziness, epilepsy, dysphonia

Uncommon (0.1% to 1%): Speech disorder, dysesthesia[Ref]


Very common (10% or more): Dysphagia (18%), dry mouth (16%)

Common (1% to 10%): Diarrhea, nausea, oropharyngeal pain, lip disorder, viral gastroenteritis, tooth extraction[Ref]


Common (1% to 10%): Sinusitis, nasopharyngitis, respiratory tract infection, viral gastroenteritis, tooth infection

Postmarketing reports: Flu-like symptoms, herpes zoster[Ref]


Common (1% to 10%): Urinary tract infection[Ref]


Common (1% to 10%): Hypertension[Ref]


Common (1% to 10%): Hypercholesterolemia, hyperglycemia[Ref]


Common (1% to 10%): Asthenia

Uncommon (0.1% to 1%): Dysphonia, facial paresis, feeling hot

Rare (less than 0.1%): Tenderness[Ref]


Postmarketing reports: Allergic dermatitis

Frequently asked questions


1. Cerner Multum, Inc. "Australian Product Information."

2. (2022) "Product Information. Xeomin (incobotulinumtoxinA)." Merz Pharmaceuticals

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.