If i take effexor (venlafaxine) xr in the evening, will it decrease daytime somnolence or does it maintain a steady state over 24 hours?

Effexor (venlafaxine) XR: I understand your concern daytime somnolence which can decrease your energy and functioning. Effexor (venlafaxine) XR is a medication for depression. Its effect lasts for 24 hours. It does not maintain steady state over 24 hours as stresses of daily life could affect your mood state. Keep a record of your sleep and specific hours of daytime somnolence and see your Psychiatrist about Effexor (venlafaxine) XR and therapy.

Side effect: Fine to try evening dose of Effexor (venlafaxine) XR. If daytime drowsiness continues, talk to prescribing doctor and consider a lower dose or alternatives. Effexor (venlafaxine) need only be taken every 24 hours. Good luck.

Neither.: It is unusual for Effexor (venlafaxine) to be sedating. It is often prescribed precisely because it is stimulating. So it is rarely taken in the evening. And while the XR has a half-life of about 15 hours, this is highly variable among different people.