Hah, I posted the same issue a while ago. I couldn't figure it out... I tried altering the time that I applied minoxidil in the PM (i.e. 4+ hours before sleeping vs. 1 or 2), using nizoral, shampooing in the PM before putting it on, wearing a thing on my head to help prevent the scratching/bleeding, etc. None of this has really helped.
After 1+ yrs on minoxidil I've determined the following:
1) There are still days where I wake up with dandruff (loosened up from the scratching), hair on the pillow, and where my scalp is severly agitated (scalp is bleeding)
2) The severity has lowered considerably over time. I think your scalp takes time to get used to minoxidil
3) I started applying minoxidil once a day in the PM so as to not make my hair styling in the morning a painful process. Basically I cut my dosage in half and so that has also helped with the irritation experienced at night (even though I still apply it in the PM). BTW, I try to compenstate by increasing the volume of minoxidil in my 1/day application
4) perhaps this is the most important comment too: use your fingers to rub the minoxidil on your scalp. My theory is that this evens out the application of minoxidil and hence makes it easier to absorb, hence preventing excessive concentrations of minxox (+ the alcohol or whatever is causing the irritation) to make you scratch the sh*t out of your scalp at night
good luck...
