science

Lower doses.

That, and it's often cut and pressed with other stimulants, like amphetamines.

The trick was to get hard before you peak, or get some little blue pills to stack with.

Although, if you're already hypertensive, probably not a good idea to mix them - or take either of those in general.

But all of this is based on my rather hazy recollection of people I was around quite a long time ago, so take it all with a grain of salt.