What measures can be taken to reduce swelling on forehead after FUE.

To reduce the chance of swelling it is advised that you sleep with your head elevated.  Doctor may also give you a steroid shot or pill(s).  

I find that making sure to keep your head elevated and above the level of your heart for the first few days while you sleep makes a big difference.  Other than that, varying docs have different post op regimens.  I will sometimes prescribe medrol dose pak's, or make sure my patients are on the appropriate supplements.  Its not a bad idea to give your doc's office a call and see what they recommend. Best of luck! 

Keeping the area elevated, icing the area, and if necessary a small dose of steroids can all help counteract swelling. In general it should go away on it's own, though, so it shouldn't be something to worry about unless its severe or lasts longer than a few days.