magnesium causes that. some people it's not big deal but for others it's an instant poop maker. if you look at laxatives it has the same ingredient.
which is exactly why sp250 generally has people destroying toilets.. never heard of this happening with jack3d though...
sp250- 350mg magnesium
jack3d- 0mg magnesium
right in jack3d's description
"MAGNESIUM
The leading Pre-workout Pump products are LOADED with Magnesium.
Now, we need magnesium for a lot of reasons, but more is NOT better & can have serious side effects and health risks. Here are some magnesium facts:
* National Academy of Sciences has set the upper tolerable limit of magnesium for adults at 350mg/day – that's equivalent to just one scoop of most products.
* Magnesium is also used as a filler - 3.5 grams each scoop is compromised from the Magnesium.
* Magnesium at high doses is used therapeutically as a laxative.
* The high Magnesium in this product is the reason people get the runs, not because of the stimulant effect.
How many times do we have to read about guys having to leave their workouts - or missing their workouts entirely - because they were stuck in the bathroom? Why take a product that is supposed to get you pumped for the gym when it will cause you to have to skip the gym? It's the magnesium that's causing this, NOT the stimulants. Jack3d contains no magnesium, so there's no issues."
so basically you dont gotta worry about the runs with jack3d.. unless your really sensitive