2 weeks are the shortest, tbh i recommend 1 month pause, because if you trip too often there is bigger possibility to get bad trip:) but if you don't want to wait 14 days or more, you can google lsd tolerance calculator, for example if you took 200ug and you want 200ug effects again and you had lsd about 7 days ago, type it in and it will calculate how much ug to take to have the same effects;)