Efficacy and Safety of Incobotulinumtoxin-A for Nonfacial Aesthetic Indications: A Prospective Case Series on Calf Contouring

Background: Botulinum toxin-A (BoNT-A) injection is a widely used cosmetic procedure in Korea to improve calf contours; however, a standardized protocol has yet to be established. While other BoNT-A formulations have been studied for calf contouring, the efficacy and safety of Inco-BoNT-A (IncoBoNT-A) specifically for this purpose remain unclear.

Objective: This prospective case series study aimed to evaluate the effectiveness and safety of IncoBoNT-A for calf contouring.

Methods: Twenty Korean women (mean age: 35.55 ± 7.37) received 75–100 U of IncoBoNT-A per calf muscle (total 150–200 U for both calves), administered intramuscularly using a 30G 0.5-inch needle. Evaluations were conducted at baseline and at 1, 3, and 6 months postprocedure. Changes in muscle size were measured via ultrasound and tape, supplemented by clinical photographs. Observer evaluations (PGAIS, Merz scales for female Asian calf) and participant satisfaction (SGAIS) were assessed at each visit, along with body weight monitoring and daily activity assessments.

Results: Both calf circumference (measured by tape) and muscle thickness (measured by ultrasound) at 2 fixed locations declined over time, with significant reductions at each visit compared to baseline. The PGAIS and SGAIS scores demonstrated consistent clinical improvement and patient satisfaction. The Merz scale indicated a shift from “severe” and “very severe” to “mild” and “moderate” ratings over time. Notably, weight gain was associated with less reduction in calf circumference.

Conclusions: A single dose of 150–200 U IncoBoNT-A is safe and effective for calf contouring. Unlike facial wrinkle treatment, weight management may be essential for achieving optimal results in calf contouring with BoNT-A.