Modafinil may affect cortisol, although data is inconsistent. Some studies show that modafinil may increase cortisol release, especially in reaction to stress, boosting alertness and cognition. Modafinil's long-term effects on cortisol and adrenal function are unknown. Increased cortisol might cause alertness and anxiousness. If you're worried about Buy modafinil online australia and it's effects on cortisol or your health, talk to a doctor.