Taking a protein shake every day may not be bad for you, but it is important to consider the type of protein shake you are taking, as well as any other supplements you may be taking. Some protein shakes contain added sugars, which can cause weight gain and other health issues if taken in excess. Additionally, if you are taking any other supplements, it is important to consider how the combination of these products may affect your health. It is always best to consult with your doctor before taking any supplements or making any drastic changes to your diet.