Originally Posted by
your_comforting_company
I can't tell you how much to chew. I have no idea, but try a little at a time, and be sure to do a skin test first, sometime before you actually need the medicine, to at least check that you aren't allergic. If you pass the test, still only sample a little to be real sure you don't have any reaction, then, provided you are certain it is a willow, and you are certain you aren't allergic, ramp up the dosage a little till your headache goes away.
Don't take chances. you say you are new to bushcraft, and you need to remember that some things out there can kill you. period. Keep that in the forefront of your mind always when using plants.
Hope that helps.