Movement of corrugator and procerus muscles can cause the skin between the brows to crease. As skin becomes less elastic over time, repeated contraction of these muscles may create visible lines and wrinkles-even when the muscles are at rest.

Botox is injected directly into the corrugator and procerus muscles, where it enters the nerve endings to block the release of acetylcholine, the chemical that causes muscles to contract. Once the muscles are at rest, the skin becomes smoother, creating a more natural and relaxed appearance.