The most common side effects of Wegovy and Zepbound include nausea, diarrhea, vomiting and constipation. The full list for each medication is below, as its Medication Guide gives it, together with the serious side effects the Medication Guide tells you to report. The person to tell is your clinician. Tell your clinician about any side effect that bothers you or doesn’t go away: message your clinician through the chat on your Dashboard and reply to the most recent message about your prescription. The Support team chat is for account and process questions, not for symptoms, so send these to your clinician.
Note: Where a line below says “right away”, don’t wait for a chat reply. Get medical help. In an emergency, call 911.
These are not all the possible side effects. For the full information, read the Medication Guide that comes with your medication. You can also report side effects to the FDA at 1-800-FDA-1088.
Zepbound
The most common side effects of Zepbound include:
nausea
diarrhea
vomiting
constipation
stomach (abdominal) pain
indigestion
injection site reactions
feeling tired
allergic reactions
belching
hair loss
heartburn
Zepbound may cause serious side effects, including the ones below. Each line says what the Medication Guide tells you to do.
Possible thyroid tumors, including cancer: tell your clinician if you get a lump or swelling in your neck, hoarseness, trouble swallowing or shortness of breath. These may be symptoms of thyroid cancer.
Severe stomach problems: tell your clinician if you have stomach problems that are severe or will not go away.
Dehydration leading to kidney problems: diarrhea, nausea and vomiting may cause a loss of fluids (dehydration), which may cause kidney problems. It’s important to drink fluids to help reduce your chance of dehydration. Tell your clinician right away if you have nausea, vomiting or diarrhea that does not go away.
Gallbladder problems: gallbladder problems have happened in some people who use Zepbound. Tell your clinician right away if you get symptoms of gallbladder problems, which may include pain in your upper stomach (abdomen), fever, yellowing of skin or eyes (jaundice) or clay-colored stools.
Inflammation of your pancreas (pancreatitis): stop using Zepbound and contact your clinician right away if you have severe pain in your stomach area (abdomen) that will not go away, with or without nausea or vomiting.
Serious allergic reactions: stop using Zepbound and get medical help right away if you have any symptoms of a serious allergic reaction, including swelling of your face, lips, tongue or throat, problems breathing or swallowing, severe rash or itching, fainting or feeling dizzy, or a very rapid heartbeat.
Low blood sugar (hypoglycemia): your risk may be higher if you use Zepbound with medicines that can cause low blood sugar, such as an insulin or a sulfonylurea. Signs and symptoms may include dizziness or light-headedness, sweating, confusion or drowsiness, headache, blurred vision, slurred speech, shakiness, fast heartbeat, anxiety, irritability or mood changes, hunger, weakness and feeling jittery.
Changes in vision in people with type 2 diabetes: tell your clinician if you have changes in vision during treatment with Zepbound.
Food or liquid getting into the lungs during surgery or other procedures that use anesthesia or deep sleepiness (deep sedation): tell everyone involved in your medical care that you’re taking Zepbound before you’re scheduled to have surgery or other procedures.
Note: Birth control pills by mouth may not work as well while you’re using Zepbound. If you take birth control pills by mouth, your clinician may recommend another type of birth control for 4 weeks after you start Zepbound and for 4 weeks after each increase in your dose. Talk to your clinician about birth control methods that may be right for you while using Zepbound.
You can also find information about side effects in the Zepbound Medication Guide.
Wegovy
The Wegovy pen and the Wegovy tablets share one Medication Guide, so this list covers both. The most common side effects of Wegovy may include:
nausea
diarrhea
vomiting
constipation
stomach (abdomen) pain
changes in skin sensations
headache
tiredness (fatigue)
upset stomach
dizziness
feeling bloated
belching
low blood sugar in people with type 2 diabetes
gas
stomach flu
heartburn
hair loss
Wegovy may cause serious side effects, including the ones below. Each line says what the Medication Guide tells you to do.
Possible thyroid tumors, including cancer: tell your clinician if you get a lump or swelling in your neck, hoarseness, trouble swallowing or shortness of breath. These may be symptoms of thyroid cancer.
Inflammation of your pancreas (pancreatitis): stop using Wegovy and contact your clinician right away if you have severe pain in your stomach area (abdomen) that will not go away, with or without nausea or vomiting. Sometimes you may feel the pain from your abdomen to your back.
Gallbladder problems: Wegovy may cause gallbladder problems, including gallstones, and some gallbladder problems need surgery. Contact your clinician if you have pain in your upper stomach (abdomen), fever, yellowing of skin or eyes (jaundice) or clay-colored stools.
Low blood sugar (hypoglycemia) in people with type 2 diabetes: Wegovy increases the risk of low blood sugar in people with type 2 diabetes, especially if you also take medicines for type 2 diabetes such as an insulin or a sulfonylurea. It can be both a serious and a common side effect. Talk to your clinician about how to recognize and treat low blood sugar, and check your blood sugar before you start Wegovy and while you take it. Signs and symptoms may include dizziness or light-headedness, sweating, shakiness, blurred vision, slurred speech, weakness, anxiety, hunger, headache, irritability or mood changes, confusion or drowsiness, fast heartbeat and feeling jittery.
Dehydration leading to kidney problems: diarrhea, nausea and vomiting may cause a loss of fluids (dehydration), which may cause kidney problems. It’s important to drink fluids to help reduce your chance of dehydration. Tell your clinician right away if you have nausea, vomiting or diarrhea that does not go away.
Severe stomach problems: tell your clinician if you have stomach problems that are severe or will not go away.
Serious allergic reactions: stop using Wegovy and get medical help right away if you have any symptoms of a serious allergic reaction, including swelling of your face, lips, tongue or throat, problems breathing or swallowing, severe rash or itching, fainting or feeling dizzy, or a very rapid heartbeat.
Change in vision in people with type 2 diabetes: tell your clinician if you have changes in vision during treatment with Wegovy.
Increased heart rate: Wegovy can increase your heart rate while you’re at rest. Tell your clinician if you feel your heart racing or pounding in your chest and it lasts for several minutes.
Food or liquid getting into the lungs during surgery or other procedures that use anesthesia or deep sleepiness (deep sedation): tell everyone involved in your medical care that you’re taking Wegovy before you’re scheduled to have surgery or other procedures.
You can also find information about side effects in the Wegovy Medication Guide.
Who to contact
For any side effect, anything about how you feel on your medication, a missed dose, or a dose change, message your clinician through the chat on your Dashboard. Reply to the most recent message about your prescription.
In an emergency, call 911. If you’re having thoughts of harming yourself, call or text 988.
Sources
This article follows the Medication Guides for Zepbound and Wegovy. If you’d like to read them yourself:
Zepbound Medication Guide, Eli Lilly and Company, revised August 2026
Wegovy Medication Guide, Novo Nordisk, revised June 2026
GenMeds checked this article against these documents on October 27, 2026. Your pharmacy’s package insert is always the final word for the medication you were dispensed.