Like all medications, semaglutide can cause side effects in some people. The most common side effects of semaglutide include nausea, diarrhea, vomiting, abdominal pain, and constipation. These side effects are usually mild and go away on their own after a few days or weeks of treatment. Other possible side effects of semaglutide include: Low blood sugar (hypoglycemia) Headache Dizziness Fatigue Decreased appetite Increased heart rate Increased blood pressure Abnormal liver function tests It is important to talk to your healthcare provider about the potential side effects of semaglutide and what to do if you experience any of them. In general, most people who take semaglutide tolerate it well and do not experience serious side effects. However, it is important to report any unusual symptoms or concerns to your healthcare provider.