OpenClaim

Botulinum Side Effects

The most commonly reported side effects of botulinum include off label use, death, and product use in unapproved indication, based on 537 FDA adverse event reports from 2004 to 2025. 12.8% of reports found the drug to be ineffective.

Botulinum side effects

Percentages show how often each reaction appears relative to total reports for botulinum.

1
Drug Ineffective12.8%69
2
Off Label Use9.5%51
3
Death7.1%38
4
Product Use In Unapproved Indication6.0%32
5
Dysphagia4.8%26
6
Migraine4.5%24
7
Dysphagia4.1%22
8
Headache3.9%21
9
Pain3.2%17
10
Dry Mouth3.2%17
11
Fatigue3.2%17
12
Treatment Failure3.2%17
13
Dry Mouth2.8%15
14
Nausea2.8%15
15
Drug Intolerance2.8%15

These are voluntary reports and do not establish that botulinum caused these reactions.

Report severity

74.1%Serious398 reports
28.5%Hospitalizations153 reports
11.7%Fatal63 reports

Seriousness is determined by the reporter, not by OpenClaim.

Botulinum drug interactions

Other drugs that appear in adverse event reports alongside botulinum. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Topiramate8.6%46
2
Baclofen8.4%45
3
Amitriptyline-hydrochloride7.6%41
4
Gabapentin7.3%39
5
Onabotulinumtoxina5.0%27
6
Zonisamide4.8%26
7
Pimavanserin4.7%25
8
Pregabalin4.3%23
9
Propranolol-hydrochloride4.3%23
10
Tramadol-hydrochloride3.5%19
11
Clonazepam3.2%17
12
Tetrabenazine3.0%16
13
Venlafaxine2.8%15
14
Acetaminophen2.8%15
15
Apomorphine-hydrochloride2.6%14

Taken alongside

1
Baclofen6.3%34
2
Acetaminophen6.1%33
3
Carbidopa6.1%33
4
Gabapentin5.6%30
5
Levodopa5.6%30
6
Aspirin4.5%24
7
Clonazepam4.5%24
8
Sertraline-hydrochloride3.5%19
9
Omeprazole3.2%17
10
Pantoprazole-sodium3.0%16
11
Simvastatin3.0%16
12
Amitriptyline-hydrochloride2.8%15
13
Levothyroxine-sodium2.6%14
14
Ergocalciferol2.6%14
15
Diazepam2.4%13

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports botulinum side effects

53.8% of botulinum adverse event reports involve female patients and 36.3% involve male patients. The largest age group is adult at 62%. These figures reflect who reports side effects, not underlying risk.

Sex

Female53.8%
Male36.3%
Unknown9.9%

Age group

< 22.1%
2–114.5%
12–172.7%
18–6462.3%
65+28.4%

What is botulinum used for

Conditions and purposes for which patients were taking botulinum when the adverse event was reported.

Anal FissureApraxiaArthritisBack PainBallismusBlepharospasmCerebral PalsyChoreaChronic Tic DisorderComplex Regional Pain SyndromeCoprolaliaDermatomyositisDiabetic GastroparesisDiabetic NeuropathyDiplegia

Showing 15 of 96 indications

Botulinum brand names and reporting trend

Botulinum is sold under the brand name Myobloc.

Brand names

Myobloc321

Quarterly reports (20042025)

20052010201520202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking botulinum with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.