The corrugator supercilii muscle is a small,^[1] narrow,^{[citation needed]} pyramidal muscle^[1] of the face.^{[citation needed]} It arises from the medial end of the superciliary arch; it inserts into the deep surface of the skin of the eyebrow.

It draws the eyebrow downward and medially, producing the vertical "frowning" wrinkles of the forehead. It may be thought as the principal muscle in the facial expression of suffering. It also shields the eyes from strong sunlight.

The corrugator supercilii muscle is located at the medial end of the eyebrow. Its fibers pass laterally and somewhat superiorly from its origin to its insertion.^[1]

The muscle acts in tandem with the orbicularis oculi muscle. The corrugator supercilii muscle acts upon the skin of the forehead superior to the middle of the supraorbital margin,^[1] drawing the eyebrow inferomedially to produce vertical wrinkles of the forehead^[3] just superior to the nose.^[1] It is the "frowning" muscle, and may be regarded as the principal muscle in the expression of suffering.^[4] It also contracts to prevent high sun glare,^[4] pulling the eyebrows toward the bridge of the nose, making a roof over the area above the middle corner of the eye and typical forehead furrows^[4] to shield the eye from excessively bright sunlight.^[1]

The muscle is sometimes surgically severed or paralysed with botulinum toxin as a preventive treatment for some types of migraine or for aesthetic reasons.^[5]

The name corrugator supercilii comes from Latin, and means wrinkler of the eyebrows.

• Corrugator supercilii seen from the inside.
• Position of corrugator supercilii muscle (red)
• Outer surface of frontal bone.
• Visible on upper portion of face.