Botulinum Toxin for Trapezius Contouring ("Shoulder Botox" / "Trap Tox"): What the Research Actually Shows
This systematic review analysed 9 studies covering 121 cases of botulinum toxin type A (BoNT-A) injection into the trapezius muscle for shoulder aesthetics — a trend often called "Barbie Botox," "Trap Tox," "Shoulder Slimming," or "Neck Toning." All cases showed some degree of aesthetic improvement. Dosages ranged from 20-50 units per side, with effects lasting approximately 4-5 months. Mild, transient side effects (temporary weakness, injection-site pain, minor bruising) occurred in 13 of 121 cases (10.7%), typically resolving within 1-2 months. No severe or permanent complications were reported. However, the evidence base remains limited in size and study design consistency, so larger, standardised randomised controlled trials are still needed.