I thought any methamphetamine based substance all did the following; raise blood pressure, alertness,causes the heart to beat rapidly...
But i recently read
that only D-methamphetamine (the most pure, crystal)makes the brain more alert but **has little effect on the heart and blood pressure**
and L-methamphetamine raises blood pressure and causes the heart to beat rapidly, but does not increase alertness very much.
Is this accurate? Why does d-meth have little to do with physical effects?