I'm in the states and Botox has a Blank Box Warning. The warning was added after the drug had been on the market due to a lawsuit in Oklahoma.
The drug maker is lucky in that there is no test for botulism, so they deny people actually get botulism from Botox, but that is what the Black Box Warning states can happen - because it's true. There is a botulism antidote, but not readily available in the US. (It is available in China as they have studied this more.)
The symptoms list is long and scary. There is a Botox Side Effects support group on Facebook.
Also, not widely known, is Botox actually ages you faster over the long run (as does filler). It's just not worth it. I would never tell anyone not to do it though. I did it successfully several times before the time it went systemic. It was awesome for my wrinkles! I looked so much better. I get it. I do.
Selfishly, the more people who do it, the more people that will get sick and at some point it will be taken off the market.
Let me just say, if you have autoimmune type symptoms or random symptoms that can't be explained because test after test comes back normal - and you do Botox - just consider your side effects may be caused by Botox.