[Botox] Consistently receiving Botox between the eyebrows

I am receiving Botox between my eyebrows consistently once every 3-4 months. My job involves reading books and doing research, but when I concentrate, I naturally frown and wrinkles are already forming. Since it takes more than a week for Botox to take effect after receiving it, we decided that it would be better to prepare for it in advance. First of all, I got it for the first time and I am getting it regularly from an inexpensive place for maintenance purposes. The force does not naturally go to the forehead, and the eyelids do not feel droopy or heavy yet. I don't know the tolerance yet (I think I've had it about 9 times? Has it been 4 years since I got Botox regularly...?)