Neurotoxin to decrease horizontal forehead crease left me with noticeable uneven eyebrows. re-injected yesterday on one side. will this work at all?

This is a common risk that can be minimized: Neurotoxin is meant to weaken the muscles in areas where it is injected. However, it does diffuse around the area where it's injected and affects neighboring muscles as well. While it is always possible that such changes, which may be undesirable, can occur, it is best to inject less initially and enhance with more product two weeks later.