MARESA® (semaglutide) pen
Your safety is our first priority. This page summarizes key medication details, possible side effects, and other important information about semaglutide treatment.
Prescribing information
Semaglutide is a GLP‑1 receptor agonist used along with a reduced‑calorie diet and increased physical activity to support weight loss in certain adults and, in some cases, adolescents with obesity or overweight. Your clinician will decide if this medication is appropriate for you.
Common side effects
- Nausea
- Vomiting
- Diarrhea
- Constipation
- Stomach pain or heartburn
These symptoms are more likely when you first start semaglutide or when your dose increases. They often lessen over time as your body adjusts. Tell your clinician if side effects are severe or do not go away.
Important safety information
Semaglutide has been associated with thyroid C‑cell tumors in animal studies. It is not known if this risk occurs in humans, but you should not use semaglutide if you or a family member has ever had medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN 2).
- You or a family member has a history of MTC or MEN 2.
- You have had a serious allergic reaction to semaglutide or any ingredient in the pen.
- Your clinician has advised you not to use GLP‑1 medicines for another medical reason.
Call your clinician or seek emergency care right away if you notice:
- Severe stomach pain that will not go away, with or without vomiting (possible pancreatitis).
- Pain in the upper right abdomen, fever, yellowing of the skin or eyes, or clay‑colored stools (possible gallbladder problems).
- Swelling of the face, lips, tongue, or throat; rash; trouble breathing; or a very fast heartbeat (possible severe allergic reaction).
- Changes in urination, swelling in your legs, or fatigue, especially if you have been vomiting or have diarrhea (possible kidney problems).
Tell your clinician about all of your medical conditions, including if you have or have had: pancreatitis, gallbladder disease, kidney problems, stomach or intestinal issues, diabetic eye disease, or other serious medical conditions.
Share a list of all medications and supplements you take. Some medicines can affect semaglutide, and semaglutide can affect how other medicines work.
Limitations of use
Semaglutide is not a replacement for insulin and should not be used with other semaglutide‑containing products or GLP‑1 medications unless specifically directed by your clinician. It is not known if semaglutide is safe and effective in all patient groups; your clinician will consider your individual situation.
This summary does not include every possible risk or side effect. Always read the Medication Guide that comes with your pen and talk with your clinician if you have questions about whether this treatment is right for you.