The most common side effect as your body adjusts to the semaglutide is nausea and we have found that B12 often will help this! The following side effects are ones that are more commonly reported: nausea, diarrhea, vomiting, constipation, stomach (abdomen) pain, headache, tiredness (fatigue), upset stomach, dizziness, feeling bloated, belching, gas, stomach flu, and heartburn. Your medical provider will review with you potential side effects prior to beginning medical weight loss so you can decide if Semaglutide therapy is the right medical weight loss program for you.