I received 50 units of botox in my glabella/forehead 36 hrs ago. now my brows have lost their arch & only the top 1/2 of my forehead rises/ is furrowed. is more botox a fix? how long must i wait?

Wait longer: You should wait about 2 weeks to allow the BOTOX to fully exert its effects. It's not unusual to see irregularities early on, as it is just beginning to work. You should not have anymore BOTOX until 2 weeks pass, otherwise you risk having a worse result.

Give 7-10 days: This depends on your desired appearance. It typically takes 7-10 days to see the initial effects of Botox and to take full action. Botox cannot be reversed. So the flattening of the arch may be due to Botox working on the outer portions of the brw/forehead with less lifting. It may be possible to add additional Botox to the central upper forehead to drop the inner portions and create a subtle arch