Why must Botox be reconstituted using 21 gauge needle? What happens if 18 gauge or 25 gage is used?

When Botox was first introduced as Botox Cosmetic, the company was somewhat emphatic about how it was to be reconstituted. The training courses back in the late middle 1990's indicated that the molecules were somewhat fragile and that allowing a quick jet of saline to hit the Botox molecules could damage them. The recommendation was to use a 21 or 22 gauge needle and resist letting the plunger pull down quickly. We replaced a nurse in the clinic who didn't do it that way and we had two vials that got injected where patients had a much poorer response and had to be re-injected. I think its a difference that probably makes a difference. We also use preservative free normal saline to reconstitute.

Dear jerronba,Botox is reconstituted using salt water prior to injection. This can be performed using any appropriate size needle.Injection is commonly performed using a very small needle. I prefer to use a 32 gage needle that is commonly called a nanoneedle.Warmest wishes,Larry Fan, MD