How long does it take gabapentin to take effect when first prescribed?

Gabapentin is used for several reasons. Which one are you using it for

The relief from gabapentin is very variable and may very well depend upon the nature of the treated condition. Also, the effect is very dose related; i.e., the initial dose may be sub-therapeutic and later, higher doses, if tolerated, can create a valuable outcome. Ask your doctor what expectations are anticipated.