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Study: Botox refrigerated for 4 weeks does not yield detectable bacteria, fungi

After administering Botox to patients, storing the vials of reconstituted toxin for 4 weeks was not associated with detectable growth of bacteria or fungi, according to recently published study findings.

One hundred and eight patients underwent injections of Botox (onabotulinumtoxinA, Allergan) from 88 100-unit vials, administered aseptically, for essential blepharospasm, hemifacial spasm or facial rejuvenation. Vials with remaining product were then stored in a refrigerator for 4 weeks. Contents were then transferred to various media and tested for bacterial and/or fungal growth using standard procedures.

Teissy Osaki

Results showed no detectable bacterial or fungal contamination was found via any of the testing methods used, according to the researchers.

Although the researchers do not recommend utilizing reconstituted onabotulinumtoxinA beyond the 24-hour period indicated by the manufacturer, they noted many physicians polled in the past have reported storing the toxin for 1 week or longer.

The researchers encouraged further study with larger number of vials and longer storage periods, which could result in a longer-than-24-hour period recommended by the manufacturer. – by Abigail Sutton

Disclosure: The researchers report no relevant financial disclosures.