Is 22 too young to have Botox? Had about 20 units places around my eyebrows to help smooth out a dent.

No, you aren't too young to have Botox. Often, young patients begin Botox early to help with prevention. If you stop using Botox, your skin will go back to normal and you won't have droopy eyebrows. Hope this helps. 

Hello Ali,
Thanks for asking this question. It is dependent entirely on the patients skin, if the practitioner and yourself feel it is necessary for wrinkle removal, than there should be no issue with botox.
Botox isn't permanent, it last for up to 3-4 months. It is entirely up to you if you choose to continue using it. Once the botox wears off, your skin returns back to its usual state. 

There is an increasing number of young people having Botox for preventative measures. Duration of Botox has many variables. This means you may not require a course of Botox every 4 months. The "frozen face" look is from completely paralysing the muscles of facial expression. Botox treatment can be tailored such that some movement still remains, yet avoids the wrinkles.