“The notion that pot has increased dramatically in potency is a DEA myth based on biased government data…samples of pot from the early ’70s came from stale, low-potency Mexican “kilobricks” left in police lockers, whose potency had deteriorated to sub-smokable levels of less than 0.5%.
These were compared to later samples of decent-quality domestic marijuana, making it appear that potency had skyrocketed. A careful examination of the government’s data show that average marijuana potency increased modestly by a factor of two or so during the seventies, and has been more or less constant ever since.
Contrary to popular myth, greater potency is not necessarily more dangerous, due to the fact that users tend to adjust (or “self-titrate”) their dose according to potency. Thus, good quality sinsemilla is actually healthier for the lungs because it reduces the amount of smoke one needs to inhale to get high.”