My doctor uses 19 units on me every 4-5 months to treat a single vertical line between my eyebrows, which always made me look angry and made people constantly ask me, "what's wrong?"
Now not only is the line gone, but I think I get fewer tension headaches in the muscle between my eyebrows because I am unable to clench it. I also find that the effects seem to last longer the more I get Botox regularly. Initially it only lasted about 3 months but now it's closer to 5. The needles they use are teeny tiny, but you have a lot of nerve endings around your eyes so it does hurt a little bit. But the amount of pain is nothing compared to getting a tattoo, or even to getting waxed!