Why isn’t this potion’s effect lasting?

Potions have a set duration; some are instant, some two minutes or more. If you die for any reason, you will lose the potions benefits. Also, some potions may state they last for ‘X' amount of time but fade before then. This is usually only applies to protection type potions that absorb damage. These potions will fade once ‘X' amount of damage has been absorbed or deflected from you.