that's what I'm using right now (cuz I still got some) and wanted to take a lot to help me with elimination in the morning - mainly because all our running around is causing us to need to eat at restaurants on a daily basis right now (FIL in nursing home 10 miles away and MIL in hospital 45 miles away)
However, I know that eventually it will quit working (for me).
Magnesium glycinate works better (for me) because I need less. Got that from my chiropractor (Metagenics)