The primary release procedure for BOTOX uses a cell-based potency assay to determine the potency relative to a reference standard. The assay is specific to Allergan's products BOTOX and BOTOX Cosmetic. One Unit of BOTOX corresponds to the calculated median intraperitoneal lethal dose (LD50) in mice. Due to specific details of this assay such as the vehicle, dilution scheme, and laboratory protocols, Units of biological activity of BOTOX cannot be compared to nor converted into Units of any other botulinum toxin or any toxin assessed with any other specific assay method. The specific activity of BOTOX is approximately 20 Units/nanogram of neurotoxin protein complex.

Contrary to popular belief, the bacteria that causes botulism, clostridium botulinum, is not part of the treatment, nor are six of the seven neurotoxins it secretes. The only substance used in Botox injections, botulinum toxin A, is carefully extracted, purified, and standardized into FDA-approved doses. Plus, the dosage is so small, it can't get beyond the muscle tissue it's injected into, meaning there's little if any chance for Botox to reach the bloodstream.
Tell your doctor if you have received any other botulinum toxin product in the last 4 months; have received injections of botulinum toxin such as Myobloc®, Dysport®, or Xeomin® in the past (tell your doctor exactly which product you received); have recently received an antibiotic by injection; take muscle relaxants; take an allergy or cold medicine; take a sleep medicine; take aspirin-like products or blood thinners.
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