Single-centre, controlled, randomized, evaluator-blinded, bilateral (split-face) comparison study in subjects with moderate to severe forehead wrinkles.

One botulinum toxin type A will be injected in one side of the forehead and the other one will be injected in the other side of the forehead at baseline. Allocation of each BoNT-A to each side of the forehead will be randomized.

There are two formulations of BoNT-A available: Botox®/Vistabel®, Allergan and Dysport®/Azzalure®, Ipsen - Galderma. These formulations behave distinctly in different ways electrophysiologically and clinically and results obtained with one formulation cannot be extrapolated to the other. There are only few clinical research directly comparing the two formulations in the treatment of forehead lines.

Inclusion Criteria:

1. Female Subjects of any race, from 18 to 65 years old
2. Moderate to severe horizontal forehead wrinkles at maximum contraction (2-3 on the Forehead Wrinkles Severity Scale) on both sides of the forehead
3. Negative urine pregnancy test at the Baseline visit for Subjects of childbearing potential

Exclusion Criteria:

1. Subjects with a washout period for procedure(s)/treatment(s) on the forehead less than:

   • Retinoid, microdermabrasion, or prescription level glycolic acid treatments 2 weeks
   • Non-ablative light treatments (e.g. Intense Pulsed Light, light-emitting diodes) 1 month
   • Ablative skin resurfacing
   • Non-ablative dermal treatment for skin tightening (e.g. radio-frequency treatments) 6 months
   • Treatment with a BoNT-A 12 months
   • Soft tissue augmentation (e.g. biodegradable products as collagen or hyaluronic acid preparations) 24 months

2. Subjects who undergone a surgical facelift;

3. Permanent or semi-permanent dermal fillers in the forehead area;

4. Known allergy or hypersensitivity to any botulinum toxin or any component of BoNT-A (1) and/or BoNT-A (2) (see package inserts);

5. Concurrent use of treatments that affect neuromuscular transmission, such as curare-like depolarizing agents, lincosamides, polymyxins, anticholinesterases affecting the striated muscle and aminoglycoside antibiotics;

6. Pregnant women, nursing mothers, or women who are planning pregnancy during the study;

5 months

All medical clinical events occurred after subject's consent signature and during the study, whether observed by the Evaluator/Injector or reported by the Subject and whether or not thought to be treatment-related were considered adverse events and collected.