Side effects? Yeah I was as curious as you are. After all, I don't want anything bad to happen to my face. I need it for my job yeah? So I asked, and I googled. Side effects, if any, are usually minor and only temporary, and usually involves a paralysis of the wrong muscle group (that's why it is SUPER important to find a trusted doctor!) Generally Botox has a very low degree of human toxicity, definitely comparitively lower than breathing in exhaust fumes standing by the road. And oh, unless abused and used on the wrong part of the body (think angry aesthetics female doctor with free access to Botox, finding out her husband is cheating...and possibly a vengeful jab at his nether regions causing paralysis and softening of the muscle....), Botox is generally safe. Lol.