Add Hopzoil to Finished Imperial?

[Clint Yeastwood]

I'm trying my first imperial stout, and it could use some sharpening up. I am thinking of increasing the carbonation and adding some Hopzoil.

I received the Hopzoil as a freebie with something I ordered. I have never used it. I have maybe 4.5 gallons of beer. I'm at about 45 IBU and would like to hit 75 or so, based on a recommendation from North Coast.

Can I get away with adding this stuff to finished beer? Their site thinks it may harm the head.

 

[Kickass]

Can’t comment on that specific product but if you want to “sharpen” it, maybe a little lactic acid or your acid of choice?

 

[CascadesBrewer]

I got a free vial of Hopzoil a while back. I added it to a 5 gal batch of hop water as the only hop addition. The flavors were rather subtle. I don't think they have any versions that add bitterness.