Ozempic Side Effects
Ozempic (semaglutide) is a once weekly injection approved for type 2 diabetes. This page explains the side effects named in its FDA approved prescribing information, in plain language: the reactions reported most often, when they tend to happen, and the serious warnings every label carries. It is education only, not medical advice.
The most common Ozempic side effects
Most of the reactions reported with Ozempic involve the stomach and digestion. That is expected from how the medicine works: it slows stomach emptying and reduces appetite. The reactions named as most common in the prescribing information are:
- Nausea. The single most frequently reported reaction, especially early in treatment.
- Vomiting. Often linked to dose increases or eating more than the stomach can now handle.
- Diarrhea. Loose or frequent stools, reported most often while the dose is going up.
- Constipation. Slower digestion can mean less frequent, harder stools.
- Stomach pain. Abdominal pain or discomfort, listed on the label as abdominal pain.
- Reduced appetite. Part of how the medicine works, and itself listed as a reaction.
Indigestion and acid reflux also appear on the label, along with belching and gas for some people. Not everyone gets these effects, and for those who do, the pattern and severity vary a lot from person to person.
When side effects tend to happen
The prescribing information notes that the stomach related reactions are most common during dose escalation, the period when the dose is stepped up every few weeks. The Ozempic dosage chart shows how gradual that schedule is, starting at a low 0.25 mg dose that exists mainly to let the body adjust. For many people, reactions that appear after an increase ease as the body gets used to the new dose. If side effects are severe or not settling, that is a common reason a prescriber keeps someone on the same dose for longer instead of following the fastest version of the schedule.
Warnings in the Ozempic prescribing information
Boxed warning: thyroid C-cell tumors. The strongest warning on the label is about a possible risk of thyroid C-cell tumors. In animal studies, semaglutide caused these tumors in rodents. It is not known whether Ozempic causes them in people. The label says the medicine should not be used by people with a personal or family history of medullary thyroid carcinoma, or with a condition called multiple endocrine neoplasia syndrome type 2.
Pancreatitis. Inflammation of the pancreas has been reported with this class of medicine. The label describes severe stomach pain, sometimes spreading to the back, as the warning sign.
Gallbladder problems. Gallstones and gallbladder inflammation have been reported. Pain in the upper right stomach area, fever, or yellowing of the skin or eyes are the signs the label points to.
Severe stomach problems. Because Ozempic slows stomach emptying, the label states it is not recommended for people with severe gastroparesis, a condition where the stomach already empties too slowly.
Diabetic retinopathy complications. The label carries a warning for people with diabetic retinopathy, a diabetes related eye condition. In one trial in people with type 2 diabetes, complications of retinopathy were reported more often in those taking semaglutide, so the label advises telling the prescriber about any history of the condition and reporting vision changes.
Allergic reactions. Serious allergic reactions, including anaphylaxis and swelling of the face, lips or tongue, have been reported with semaglutide medicines.
Low blood sugar with certain other medicines. Used on its own, Ozempic is not expected to cause low blood sugar in most people. The label warns the risk rises when it is combined with insulin or a sulfonylurea.
When to get medical care promptly
Some symptoms should never be waited out. Seek medical care promptly for severe or persistent stomach pain, signs of an allergic reaction such as swelling of the face, lips or tongue or trouble breathing, yellowing of the skin or eyes, or a lump or swelling in the neck, a hoarse voice, or trouble swallowing. Ongoing vomiting or diarrhea that stops you drinking enough fluid also deserves a prompt call, because dehydration can strain the kidneys.
Frequently asked questions
What are the most common side effects of Ozempic?
The reactions reported most often in the Ozempic prescribing information are gastrointestinal: nausea, vomiting, diarrhea, constipation and stomach pain, along with a reduced appetite. Indigestion and reflux are also listed. These effects are reported most often while the dose is being increased.
Do Ozempic side effects settle down over time?
For many people, yes. The label notes that stomach related reactions happen most often during dose escalation. As the body adjusts to a steady dose, they often become milder or less frequent, although this is not true for everyone, and severe or ongoing symptoms should always be raised with the prescriber.
What is the boxed warning on the Ozempic label?
The boxed warning is about thyroid C-cell tumors. In studies, semaglutide caused these tumors in rodents. It is not known whether Ozempic causes them in people. Because of this, the label says the medicine should not be used by people with a personal or family history of medullary thyroid carcinoma, or with multiple endocrine neoplasia syndrome type 2.
Can Ozempic cause low blood sugar?
On its own, Ozempic is not expected to cause low blood sugar in most people. The label warns that the risk rises when it is used together with insulin or with a sulfonylurea medicine, because those medicines can lower blood sugar themselves.
When should someone taking Ozempic get medical care promptly?
The warnings on the label point to a few situations: severe or persistent stomach pain, which can be a sign of pancreatitis; signs of a serious allergic reaction such as swelling of the face, lips or tongue or trouble breathing; yellowing of the skin or eyes; and a lump or swelling in the neck, hoarseness or trouble swallowing.