Originally Posted by mrsD

magnesium citrate is both.

In lower doses it does not usually have laxative action.

In higher doses it may. People vary in response to it.
Some can take more before getting loose. The liquid in the store is designed to be taken all at once for bowel prep for Xrays and various tests.

Others like me get effects at lower doses. That is why I prefer food sources as a primary source.

Citrate Magnesia (liquid) has 290mg/30ml. The bottle is 8 ounces or 2400 mg/8oz or 2.4 grams

Solgar Magnesium Citrate has 200mg/tablet.
If your friend takes them all at once, they may be more laxative than if she spaces them during the day. But no guarantees on that, since people differ alot.

Both are the same thing, only different in dose.