Does Prozac Cause Insomnia?

Yes, Prozac (fluoxetine) can cause insomnia in approximately 10-15% of patients. This sleep disruption typically occurs because Prozac is a stimulating SSRI antidepressant that increases serotonin levels, which can interfere with normal sleep patterns. The insomnia often presents as difficulty falling asleep, frequent nighttime awakenings, or early morning awakening. Most sleep-related side effects are more common during the first few weeks of treatment and may improve as your body adjusts to the medication. Taking Prozac in the morning rather than evening can help minimize sleep disturbances, and some patients find their sleep patterns normalize after 4-6 weeks of consistent use.