Coffee does affect blood pressure by raising it slightly, so that's not likely to be the cause of your boner issue. Increased BP makes erections more of a challenge.

Erections after smoking cannabis are fairly common, especially in young men. Initially you get an increased heart rate and slightly raised BP, which is likely to be a phase when getting an erection would be more difficult. But after the vaso-dilating effects of the cannabis fully kick in, assuming you're not smoking a strongly vasoconstrictive sativa, and once that initial constriction phase has passed and your vessels fully relax, that's when the blood flow and hydraulics are in optimum shape for spontaneous erections.

The subject is one of endless fascination to me, not having the same erectile ability myself (I know we have them, too, but they're in a much less visible organ). I also have picked up a lot of information over the years about circulatory medicine since I'm married to a man who works in that field.
birdgirl73 Reviewed by birdgirl73 on . Does coffee affect your blood pressure? Boner while high problem! Yah, I also have the boner while high problem. If coffee affects blood pressure, that has to be my problem. I drink a lot of strong black coffee all day. My boner problem isn't as bad as other members just minor. I'm going to do an experiment, no coffee for a week, then a toke. I'll post my results for other guys that get boners after smoking. This shit is seriously embarrassing when your hanging out with friends(of the same sex)! Rating: 5