Comparison of the efficacy and safety between a new monophasic hyaluronic acid filler and a biphasic hyaluronic acid filler in correcting facial wrinkles

Background The longstanding and common use of hyaluronic acid (HA) has driven the expanded development of various commercial HA fillers. However, differences in the components of these HA fillers lead to variations in their effect. We compared the <i>in vivo</i> safety and efficacy of biphasic HA (BHA) and a new monophasic HA (MHA) for improving facial wrinkles. We investigated differences in outcomes after their injection into nasolabial folds (NLFs) using the Wrinkle Severity Rating Scale (WSRS), patient satisfaction using the Global Aesthetic Improvement Scale (GAIS), and pain using a visual analog scale (VAS). We also performed a safety assessment of the two fillers.Methods This matched-pair, double-blind, randomized study compared the degree of temporal wrinkle improvement in the NLFs of 91 participants using the BHA filler versus the new MHA filler. Safety and efficacy were compared at 8 and 24 weeks.Results At 24 weeks after application, the average WSRS scores were 2.17±0.72 (BHA) and 2.07±0.71 (MHA) (P=0.034). The average GAIS scores, as measured by a treating investigator at 8 weeks and 24 weeks, were 0.94±0.76 (BHA) and 0.98±0.78 (MHA) at 8 weeks (P=0.181), and 0.44±0.64 (BHA) and 0.49±0.69 (MHA) at 24 weeks (P=0.103). The VAS pain score was 0 points at 30 minutes after filler application in both groups.Conclusions Both the BHA filler and the new MHA filler were safe and effective for improving facial wrinkles in NLFs, but the new MHA filler was more effective for the cosmetic improvement of wrinkle severity than the BHA filler.