Modafinil is commonly prescribed to help people stay awake for conditions like narcolepsy, obstructive sleep apnea, and shift work sleep disorder. While many tolerate it well, about 10% to 15% of users report Modafinil side effects, ranging from minor discomfort to symptoms that are harder to brush off.
Some people take it and feel sharper with barely any issues. Others notice changes almost immediately. Head pressure, irritability, poor sleep, or a sense that something just feels “off” aren’t uncommon, especially when the dose or timing isn’t right. Even small differences in health, sleep debt, or sensitivity to stimulants can change how the drug feels.
Most people notice pretty quickly whether Modafinil agrees with them or not. A mild headache or dry mouth might pass. But if something keeps bothering you—or starts getting worse—it’s usually a sign to stop and pay attention, not power through it.
