BACKGROUNDMore than 90% of women report concerns of cellulite on their skin. Poly-l lactic acid (PLLA-SCA) is a biocompatible, semipermanent, synthetic filler that induces neocollagenesis.OBJECTIVETo investigate the safety and efficacy of PLLA-SCA for the treatment of cellulite of the buttock and thigh regions.METHODSThis was a prospective, single-center, double-blinded, split-body, clinical trial of 20 women with slight to moderate skin laxity of the buttocks and/or thighs contributing to mild-to-moderate cellulite. Each subject’s buttocks and thighs were randomized to receive injections with up to 2 vials of PLLA-SCA or the equivalent volume of bacteriostatic water per treatment area. Subjects received at total of 3 treatments 4 weeks apart and were followed for 330 days.RESULTSTreatment of the buttocks with PLLA-SCA resulted in significant reduction of depression depth, improvement in the morphological appearance of the skin, improvement in the grade of skin laxity, and overall improvement in cellulite appearance. Treated thighs showed reduction in the depth and number of depressions and an improvement in overall cellulite appearance. No significant procedure side effects were found.CONCLUSIONPoly-l lactic acid offers an effective and safe method for treating cellulite of the buttocks and thighs.