Without testing you have no idea what will be more harmful, that goes for both Molly and pills. Many people speculate that Molly is more trusted and pure, but both capsuled powder, sold as molly, and pills have been known to be adulterated.
A test kit can greatly reduce the chance of harm, as it is mostly revealing as to what you're taking. You can get one here:
www.dancesafe.org
everybody thinks their molly is pure it seems like, and they're mostly wrong.