Propanolol is a beta-blocker used for high blood pressure. Not everyone can take it and it really depends a lot on blood pressure. When my blood pressure was really high I took the stuff and it did nothing for the headaches. Unfortunately, or fortunately depending on how you look at this one, I lost 100 pounds in a year, the blood pressure went down but my dosage wasn't adjusted with the weight loss. I was on the floor with almost no blood pressure. I actually have fewer headaches without it.
I now see a neurologist who specializes in headaches. I mostly manage by knowing what are and aren't triggers. The headache diary was illuminating. I never realized what I was doing before I would get a really bad one.
Some people are trying ergotamine deratives with some success.