Thoughts? could protein shakes make me gain weight?

No: Weight gain comes from muscle mass and fat loss. Muscle weighs more than fat, which is why people who appear 'ripped' weigh so much, but aren't obese. Protein will help to repair and build muscle, but not only if used in conjunction with a safe, effective, and committed workout routine. See your sports physician or personal fitness trainer to get you on the right track to produce the best result.