Get your blood pressure taken and get back to us. Headaches and blood pressure can go hand-in-hand. It's very common to see blood pressures increase quite a bit when on compounds such as M-Drol. Supplements like Hawthorn Berry can help.
Staying very well hydrated should help a little. Drink at least 1-1.5 gallons a day, tapering off towards nighttime so you're not up all night peeing.
If things start getting worse and you want to seek a medical opinion, don't neglect to tell them that you're on M-Drol (it is legal after all). They may not know what that is, but hopefully if you're taking it you should be able to explain it quite throughly.
Good luck, man.. Hope you get to feeling better
