The corrugator supercilii is a small, narrow facial muscle located at the medial end of the eyebrow. It lies between the frontalis and orbicularis oculi muscles.
 

Origin: medial part of the superciliary arch (frontal bone).

Insertion: muscle penetrates the frontalis and orbicularis oculi muscles and inserts into the skin over the middle of the eyebrow.

Action: pulls the skin of the eyebrow downward and medially, and produces vertical wrinkles of the forehead.

Innervation: temporal branch of facial nerve (CN VII).

Blood supply: branches of the superficial temporal and ophthalmic arteries.