I didn't trust my doctor when she gave me medication with a substantial chance of side-effects I wouldn't have liked.

That could be because your doctor was trying to prevent a nocebo effect. If a side effect is directly harmful (not simply a nuisance) or put you at risk say for example petic ulcer when taking large doses of NSAID:s e.g. aspirin, doctors are generally inclined to inform you - if they know their stuff.