CRL-40,941 (also known as fladrafinil and fluorafinil) is a eugeroic closely related to adrafinil and modafinil. It is the bis(p-fluoro) ring-substituted derivative of adrafinil. CRL-40,941 was found to produce antiaggressive effects in animals, which adrafinil does not produce, and is purportedly 3 - 4 times stronger than adrafinil.