Short answer: Evolence is FDA-approved for the nasolabial folds and injection into the area between the eyebrows is off-label.
Injection of filer material between the brows has been the subject of controversy, because some filler materials injected in this area have resulted in vascular injury which has sometimes even resulted in skin necrosis (death) and scar. The glabella (region between the brows) is subject to a higher incidence of vascular compromise because many vessles are in this area. That being said, fillers are used in the glabella all the time.
BoTox alone offers such an impressive improvement to glabellar rhytids (wrinkles between the brows) that BoTox should be the first step. If further improvement is required, then filler materials should be considered with caution and Evolence (Dermicol P-35) could be considered.