A prospective, randomized, parallel group study analyzing the effect of BTX-A (Botox) and nonanimal sourced hyaluronic acid (NASHA, Restylane) in combination compared with NASHA (Restylane) alone in severe glabellar rhytides in adult female subjects: Treatment of severe glabellar rhytides with a hyaluronic acid derivative compared with the derivative and BTX-A

BACKGROUND. Over the past 15 years, BTX-A has become the standard treatment for dynamic glabellar furrowing.(1,2) Some individuals have resting glabellar rhytides that are sufficiently deep that they respond poorly to BTX-A alone.(3,4) OBJECTIVE. To compare the efficacy of BTX-A combined with intradermal nonanimal stabilized hyaluronic acid (NASHA) with the efficacy of NASHA alone in females with moderate to severe glabellar rhytides. METHODS. This was a prospective randomized study of 38 subjects with moderate to severe glabellar rhytides. Half of the subjects were treated with BTX-A and NASHA and the other half with NASHA alone. Their response was assessed clinically and photographically. RESULTS. By comparison with the NASHA-alone group, the BTX-A plus NASHA group showed a better response both at rest and on maximum frown, and this response was maintained for longer. The median time for return to preinjection furrow status occurred at 18 weeks in the NASHA-alone group compared with 32 weeks for the BTX-A plus NASHA group.