there are a bunch of factors when you are talking about lowering tolerance. Have you been smoking the same kind of weed for that entire period? Most of it? How many times have you smoked (on average) per day?

If you've been puffing on the same shit for weeks then yeah, you would need a decent amount to do the trick. If you are looking to get high, id recommend switching to a different more potent bud.

Also have a week long break, then smoke one to your head, you should get wrecked.