You can drink up to two standard Ensure shakes per day. For the protein- specific Ensure shakes, the limit is no more than three per day. Some sources recommend a maximum of 6-8 servings per day for Ensure Plus, but the typical advice is that two normal shakes and three protein shakes daily is the limit to avoid nutritional imbalances and potential health risks. It is best to use Ensure as a dietary supplement rather than a sole nutrition source and consult a healthcare professional for personal recommendations.