Botulinum Toxin Type B: uses, dosing, side effects & brands
Botulinum Toxin Type B is a medicine sold in the U.S. under one brand, for sialorrhea, torticollis and dystonia. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Treats
- Sialorrhea, Torticollis and Dystonia
- Available as
- Injectable
- Sold as
- Myobloc
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
- Boxed warning
- Boxed warning
How botulinum toxin type b is dosed
From the FDA label for Myobloc (application BLA103846). Other botulinum toxin type b products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Cervical Dystonia: for patients with demonstrated tolerance of botulinum toxin injection, recommended total dosage is 2,500 Units to 5,000 Units divided among effected muscles ( 2.2 ) Chronic Sialorrhea: recommended dosage is 1,500 Units to 3,500 Units; 500 Units to 1,500 Units per parotid gland and 250 Units per submandibular gland; no more frequent than every 12 weeks ( 2.3 ) 2.1 Instructions for Safe Use The potency units of MYOBLOC are specific to the preparation and assay method utilized. They are not interchangeable with other preparations of botulinum toxin products and cannot be compared to or converted into units of any other botulinum toxin products [see Warnings and Precautions (5.2) , Description (11) ] . Each single-dose vial should only be used during one session and only for one patient. Discard any remaining solution in the vial. MYOBLOC is ready to use; no reconstitution required. MYOBLOC may be diluted with 0.9% Sodium Chloride Injection. Once diluted, the product must be used within 4 hours as the formulation does not contain a preservative. 2.2 Dosing for Cervical Dystonia The recommended initial dosage of MYOBLOC for cervical dystonia patients with a prior history of tolerating botulinum toxin injections is 2,500 Units to 5,000 Units divided among affected muscles [see Clinical Studies (14.1) ] . Patients without a prior history of tolerating botulinum…
Botulinum Toxin Type B side effects
The following clinically significant adverse reactions to MYOBLOC are discussed in greater detail in other sections of the labeling: Spread of Toxin Effect [see Warnings and Precautions (5.1) ] Lack of Interchangeability Between Botulinum Toxin Products [see Warnings and Precautions (5.2) ] Hypersensitivity Reactions [see Warnings and Precautions (5.3) ] Dysphagia and Breathing Difficulties [see Warnings and Precautions (5.4) ] Human Albumin and Transmission of Viral Diseases [see Warnings and Precautions (5.5) ] The most common adverse reactions (>5% of MYOBLOC-treated patients at any dose and >5% more common than placebo) include: Cervical Dystonia: dry mouth, dysphagia, injection site pain, and headache ( 6.1 ) Chronic Sialorrhea: dry mouth and dysphagia ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Solstice Neurosciences at 1-888-461-2255 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in clinical trials of another drug and may not reflect the rates observed in practice. Cervical Dystonia In the treatment of cervical dystonia, MYOBLOC was studied in both placebo-controlled single treatment studies and open-label repeated treatment studies; most treatment…
Who shouldn’t take botulinum toxin type b
MYOBLOC is contraindicated in patients with: A known hypersensitivity to any botulinum toxin product or to any of the components in the formulation [see Warnings and Precautions (5.3) , Description (11) ] Infection at the proposed injection site(s) MYOBLOC is contraindicated in patients with: Known hypersensitivity to any botulinum toxin preparation or to any of the components in the formulation ( 4 , 5.3 ) Infection at the proposed injection site(s) ( 4 )
Botulinum Toxin Type B drug interactions
Co-administration with aminoglycosides or other agents interfering with neuromuscular transmission may potentiate effects of MYOBLOC ( 7.1 ) Co-administration or overlapping of botulinum toxin serotypes (within 4 months) may potentiate neuromuscular paralysis ( 7.3 ) 7.1 Aminoglycosides and Other Agents Interfering with Neuromuscular Transmission Co-administration of MYOBLOC and aminoglycosides or other agents interfering with neuromuscular transmission (e.g., curare-like compounds) should only be performed with caution as the effect of the toxin may be potentiated. 7.2 Anticholinergic Drugs Use of anticholinergic drugs after administration of MYOBLOC may potentiate systemic anticholinergic effects. 7.3 Other Botulinum Neurotoxin Products The effect of administering different botulinum toxin products at the same time or within several months of each other is unknown. Excessive neuromuscular weakness may be exacerbated by administration of another botulinum toxin prior to the resolution of the effects of a previously administered botulinum toxin. 7.4 Muscle Relaxants Excessive weakness may also be exaggerated by administration of a muscle relaxant before or after administration of MYOBLOC.
Every botulinum toxin type b product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Myobloc.
What people report to the FDA about botulinum toxin type b
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 38 reports naming botulinum toxin type b, and the FDA flagged 87% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- constipation3 reports
- dry mouth3 reports
- dysphagia3 reports
- facial spasm3 reports
- hypoaesthesia3 reports
- paresis3 reports
- abortion spontaneous2 reports
- accommodation disorder2 reports
Read these as a signal, not a rate. A report does not mean botulinum toxin type b caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
Related calculators
Frequently asked questions
What is botulinum toxin type b?
Myobloc (Botulinum Toxin Type B) is a medication used to treat Sialorrhea, Torticollis, Dystonia, Neck Pain.
Can you take botulinum toxin type b with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run botulinum toxin type b against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does botulinum toxin type b come in?
Across the brands we track, botulinum toxin type b is currently marketed as injectable, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic botulinum toxin type b?
We do not currently list a generic-labelled botulinum toxin type b product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Botulinum Toxin Type B: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/botulinum-toxin-type-b
- MLA
- “Botulinum Toxin Type B: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/botulinum-toxin-type-b.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for botulinum toxin type b on DailyMed (NIH) ↗ — including its boxed warning in full.