It all matters what you buy. If you get the leaf product, it would take you a few bong loads to really get you to start breaking through, but chances are you won't.

Any extract is pretty potent.

if you really want to trip, go for the "Purple Sticky Salvia". It's expensive, but they sell it at most headshops now a days, and you WILL GET YOUR MONEY'S worth. I guarantee that one bong load that is held in for 10 seconds of 20x purple sticky will have you breaking through.

Salvia is not for the weak hearted. It is a very, very intense, and usually overwhelming. I'd suggest you to read up some more on the drug, and read about other's experiences before messing with this stuff.

Salvia is by far the weirdest drug I have ever done, and I am quit familiar with psychotropics.