Last reviewed 2026-04-20 · How we verify

Botox (ONABOTULINUMTOXINA)

BOTOX blocks neuromuscular transmission by inhibiting acetylcholine release through cleavage of SNAP-25.

Botox (onabotulinumtoxina) is a small molecule acetylcholine release inhibitor developed by Allergan, now owned by the same company. It is used to treat various conditions, including overactive bladder, migraines, and facial spasms. Botox is a patented medication with a range of approved indications. Key safety considerations include potential side effects such as drooping eyelids and facial weakness. It has been FDA-approved since 2010.

At a glance

Mechanism of action

BOTOX works by binding to nerve terminals and preventing the release of acetylcholine, a neurotransmitter essential for muscle contraction. This leads to a localized reduction in muscle activity and can also affect sweat glands and bladder function when injected into these areas.

Approved indications

• Overactive Bladder
• Urinary Incontinence due to Detrusor Overactivity
• Neurogenic Detrusor Overactivity
• Chronic Migraine
• Spasticity
• Cervical Dystonia
• Severe Axillary Hyperhidrosis
• Blepharospasm
• Strabismus
• Cervical Dystonia

Boxed warnings

• WARNING: DISTANT SPREAD OF TOXIN EFFECT Postmarketing reports indicate that the effects of BOTOX and all botulinum toxin products may spread from the area of injection to produce symptoms consistent with botulinum toxin effects. These may include asthenia, generalized muscle weakness, diplopia, ptosis, dysphagia, dysphonia, dysarthria, urinary incontinence and breathing difficulties. 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 treated for spasticity and other conditions, particularly in those patients who have an underlying condition that would predispose them to the se symptoms. In unapproved uses and in approved indications, cases of spread of effect have been reported at doses comparable to those used to treat cervical dystonia an d spasticity and at lower doses [ see Warnings and Precautions ( 5.1 )] . WARNING: DISTANT SPREAD OF TOXIN EFFECT See full prescribing information for complete boxed warning. The effects of BOTOX 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 an underlying condition that would predispose them to these symptoms. ( 5.1 )

Common side effects

• Urinary tract infection
• Dysuria
• Urinary retention
• Bacteriuria
• Residual urine volume*

Drug interactions

• Aminoglycosides
• Other agents interfering with neuromuscular transmission (e.g., curare-like agents)
• Muscle relaxants
• Anticholinergic drugs
• Other botulinum neurotoxin products

Key clinical trials

• Serratus Plane Block (SPB) Versus Capsaïcine Versus Botox-A for Chronic Neuropathic Pain in Post-mastectomy Syndrome (PHASE2)
• A Study to Evaluate Patient Satisfaction With the Overall Face and Neck Appearance After Combined Treatment of OnabotulinumtoxinA, JUVÉDERM® Products, KYBELLA, CoolSculpting Elite and SkinMedica Products (PHASE4)
• DaxibotulinumtoxinA Injection for Treatment of Adductor Spasmodic Dysphonia (PHASE1,PHASE2)
• DaxibotulinumtoxinA for Blepharospasm (PHASE2)
• Prospective, Non-interventional Study Assessing Periorbital Rejuvenation Procedure
• Effectiveness and Safety of Early Intramuscular Botulinum Toxin Injections to Prevent Shoulder Deformity in Babies With Obstetrical Brachial Plexus Palsy (PHASE3)
• Study to Compare the Efficacy and Safety of NT 201 (Botulinum Toxin) With Placebo for the Treatment of Lower Limb Spasticity Caused by Stroke or Traumatic Brain Injury (PHASE3)
• A Clinical Trial to Evaluate Efficacy and Safety of Xeomin® Injections for Preventing Chronic Migraine (PHASE3)

Patents

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Botox CI brief — competitive landscape report
• Botox updates RSS · CI watch RSS
• Allergan portfolio CI