Here's some information from FRAME
FRAME is deeply concerned about the use of botulinum toxin (like botox) for cosmetic purposes, and the apparent indifference by its users to the intense animal suffering its production causes. There is no excuse for animals being subjected to painful and distressing procedures for the sake of human vanity.
The toxin is produced by bacteria, but, since it its strength varies, each new batch has to be tested separately, to determine its potency and its toxicity. It is tested on mice, which are dosed until they are paralysed and half of them die. There is currently no accepted non-animal, test to protect the safety of people receiving the treatment although there is a more humane one that ends when the mouse’s body goes limp, rather than full paralysis.
There are important medical reasons for the use of botulinum toxin such as treating squints and some forms of cerebral palsy, so some needs to be produced for those
reasons. UK law prevents animal tests on cosmetic products but botulinum procedures are invasive and performed by a doctor, so they are classed as surgery and the toxin is tested as a medicine.
FRAME believes batches of botulinum toxin should be tested according to the purpose for which they will be used so that those intended for cosmetic use cannot be tested
on animals. All trivial, non-medical uses of botulinum toxin should be stopped until it can be tested by humane methods.