Yes, some people may have an allergic reaction to certain ingredients in protein powder, such as dairy or soy. Symptoms of an allergic reaction can include hives, itching, difficulty breathing, and swelling of the face, lips, tongue, or throat. If you suspect you have an allergy to a component in protein powder, it is important to seek medical attention immediately. Before taking any new supplements, it is advisable to consult a healthcare professional to assess any potential health risks, especially if you have a known allergy or medical condition.