Duration of Semaglutide Side Effects
Semaglutide is used to treat type 2 diabetes and obesity. With a lower dose, semaglutide can reduce your blood sugar by increasing insulin release. In higher doses, semaglutide is used for weight loss. Because semaglutide has many effects on the body, it can work for weight loss in people with or without diabetes.
Before talking to your doctor about semaglutide, it’s helpful to understand semaglutide’s potential side effects and how long they are likely to last. Of course, since semaglutide is relatively new, there is not as much clinical trial and post-marketing data available on side effects as there is on older medications. It is also important to recognize that the severity and duration of side effects vary by person.
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How Common Are Side Effects with Semaglutide Use?
Semaglutide has several short and long-term side effects. The most common semaglutide side effects are gastrointestinal, such as nausea, vomiting, diarrhea, and constipation.
Semaglutide’s safety and effectiveness for treating obesity have been tested in a series of clinical trials called the STEP and SUSTAIN trials. The STEP trials used higher semaglutide doses to treat obesity. Higher semaglutide doses are more likely to cause side effects.
The STEP 5 trial looked at semaglutide use over two years. Previous clinical trials lasted up to 68 weeks. Patients with obesity or overweight with a weight-related medical condition but not type 2 diabetes were enrolled in the study.
In the STEP 5 trial, 152 people took semaglutide, and 152 took the placebo. Of these, 96% of those taking semaglutide reported an adverse event, but so did 90% of people taking the placebo.
This table shows the side effects reported by at least 10% of trial participants (1).
|Side effects||% in people taking semaglutide||% in people taking a placebo|
|Upper abdominal pain||15%||7%|
|Upper respiratory infection||13%||15%|
Comparing the percentages of people with a side effect taking semaglutide and a placebo can help determine whether or not the side effect was medication related.
Which Side Effects Are Temporary?
Gastrointestinal side effects, including nausea, vomiting, diarrhea, and constipation, are the most commonly reported side effects when taking semaglutide. These side effects were more common in the semaglutide than in the placebo group.
Most gastrointestinal side effects were rated as mild-to-moderate in severity. They were most common when first starting semaglutide and when increasing the dose. In most cases, these side effects were temporary. About 4% of trial participants taking semaglutide stopped taking it due to gastrointestinal side effects (1).
Semaglutide side effects that are usually temporary include:
Gastrointestinal side effects are common when taking any of the GLP-1 (glucagon-like peptide-1 receptor) agonists. Gastrointestinal side effects from semaglutide can happen even when you have not eaten. Researchers think that the side effects are not from semaglutide’s effects on the stomach and gut.
Instead, researchers think that an interaction between semaglutide and receptors in the brain causes gastrointestinal side effects. Slowly increasing semaglutide dosing works for many people. But, some people will still have nausea and diarrhea, even with this approach. Researchers are investigating why this happens (2).
Which Side Effects Typically Continue with the Use of Semaglutide?
Most of the side effects listed for semaglutide do not continue with the use of semaglutide. More serious side effects that would have continued typically cause people to stop taking the medication.
- Pancreatitis: This is an inflammation of the pancreas. It is a serious medical condition. Common symptoms include abdominal pain, nausea, vomiting, fever, and back pain. Pancreatitis is thought to be secondary to increased production of enzymes and insulin in the pancreas. Pancreatitis is rare. If you develop pancreatitis while taking semaglutide, you will need to stop taking the medication.
- Acute kidney failure: In rare cases, semaglutide use is associated with acute kidney injury. It is unclear whether rapid weight loss, dehydration, or the worsening of a preexisting kidney disease is the cause. If you have decreased urination, concentrated urine, or swelling of your hands or feet (3). Talk to your doctor to discuss treatment options and the risks and benefits of continuing with semaglutide.
- Allergic reactions: If you develop an allergic reaction to semaglutide or any of its components, you will need to stop treatment immediately. Symptoms from allergic reactions are expected to worsen (and can be fatal) if you continue to take the medications.
- Gallbladder disease: About 2% of people taking semaglutide in clinical trials had gallbladder disease. Symptoms of gallbladder disease include pain in the upper right quadrant of your abdomen, fever, a yellowish tinge to the skin and eyes (jaundice), and clay-colored stools (4). If you experience these symptoms, contact your doctor right away to discuss your treatment options.
- Thyroid tumors: Semaglutide products have a boxed warning for thyroid tumors. This is the strictest warning the FDA requires drug manufacturers to include on their labels. In animal studies, rodents developed thyroid tumors in response to GLP-1 agonists. This increased risk has not been confirmed in human studies. Tell your doctor if you have a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia (MEN) type 2. These are contraindications to taking semaglutide.
What Happens When You Stop Taking Semaglutide?
Semaglutide increases insulin release in response to meals. When you stop taking semaglutide, you will probably have increased blood glucose, especially if you have type 2 diabetes.
People who take semaglutide for weight loss and then stop taking it regain about two-thirds of their lost weight. This was demonstrated in a large clinical trial funded by Novo Nordisk, the company that makes Ozempic and Wegovy(5).
Current anti-obesity medications are very effective, as shown in semaglutide before and after results and case studies.
Obesity is a chronic disease. When you lose weight, it activates biological changes that prevent you from maintaining your weight loss. So, weight regain is common (5).
Talk to your doctor about your long-term weight management goals and plans. Try to make lifestyle changes that support your weight loss, especially if you plan to stop semaglutide treatment.
How Long Can You Stay on Semaglutide?
Obesity is a chronic metabolic disease. Like other chronic diseases, long-term treatment is necessary. You should plan to stay on semaglutide as long as you do not have any significant side effects and you and your doctor have determined it is the best treatment option for you.
The STEP 5 clinical trial monitored patients who took semaglutide for two years. They experienced continued weight loss and decreased risk of cardiovascular disease. The side effects seen in this longer trial were the same as those seen in other semaglutide clinical trials (1).
How To Manage Side Effects
If you have side effects from semaglutide, contact your doctor. You may need to switch to a different anti-obesity medication, decrease your medication dose, or more slowly increase your semaglutide dose.
Tips for managing gastrointestinal side effects from semaglutide include:
- Eat more slowly
- Consume smaller meals more frequently
- Stay upright for 30 minutes after eating
- Avoid high-fat meals
When To Talk to Your Doctor
If your gastrointestinal side effects persist or increase in intensity, or you have pain, contact your doctor. Seek emergency care if you think you may have gallbladder disease, pancreatitis, or an allergic reaction.
Review the side effects associated with semaglutide use. If you have any side effects that are increasing in intensity or are persistent, contact your doctor to discuss your treatment options.
- Wilding JPH, Batterham RL, Davies M, Van Gaal LF, Kandler K, Konakli K, Lingvay I, McGowan BM, Oral TK, Rosenstock J, Wadden TA, Wharton S, Yokote K, Kushner RF, Group SS. Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension. Diabetes, Obesity and Metabolism. 2022;24(8):1553-1564.