Is acne a side effect (or adverse effect) of emergency contraceptive pills?

Yup: Can cause acne in some patients.

BigPicture Viewpoint: Effects routine, what choices/outcomes are about. Our bodies mostly constructed of water, ~52-62% of body mass. Pure water (& EVERYTHING else) has effects, some called side-effects. Too much water in body, or a specific location, called edema (eg. too much in lungs & can't breath/drowning), too little=dehydration; problems the other way. Life about complex balances. See: http://goo.gl/0eH4wq, etc