You may not see first-week results with Wegovy treatment. It often takes weeks to months to see significant weight loss. It’s possible that you could have first-week side effects, including nausea, diarrhea, or vomiting.
Wegovy (semaglutide) is FDA approved for weight management in people who are overweight or have obesity. It’s a once-weekly injection. (This article explains calculating body mass index [BMI], which is used to define “overweight” and “obesity.”) People with overweight also must have at least one weight-related condition, such as:
Read on to learn what you might expect in your first week of treatment with Wegovy. You can also learn how long it generally takes to see noticeable weight loss.
Note: Combining Wegovy with diabetes or other weight loss medications can cause serious side effects. It’s important to use other drugs only if your doctor says it’s okay to do so. Also, do not change your dosage without first talking with your doctor.
You’re unlikely to see any noticeable changes in your weight during the first week of Wegovy treatment. It takes some time for the medication to take effect. Even so, your doctor may notice changes in some of your health markers. These might include blood pressure or blood sugar levels.
Most studies examining the effectiveness of Wegovy for weight loss have looked at results over 12 weeks or longer. But some people may have noticeable weight loss in 4 weeks or even less.
In their first week of treatment, some people may develop side effects. It’s possible that these might occur within hours to days of their first dose. But the timing and degree of side effects vary widely among people.
Some of the most common side effects of Wegovy include:
- nausea and vomiting
- diarrhea
- constipation
- abdominal pain
- headache
- fatigue
- upset stomach
- dizziness
- bloating
- burping
- gas
- low blood sugar in people who have type 2 diabetes
It’s not uncommon to experience side effects in the later weeks of Wegovy treatment. But keep in mind that the timing and degree of side effects vary widely among people.
If you do develop side effects, it’s important to know that doesn’t mean you’re more or less likely to experience weight loss.
In clinical studies, some people had side effects that persisted. About 8% of these people discontinued medications containing semaglutide. (Semaglutide is the active ingredient in Wegovy.)
Wegovy side effects generally lessen over time as your body adjusts to the medication. You may be able to reduce some side effects of Wegovy by adjusting your dose. But it’s important not to adjust your dose without first discussing it with your doctor.
Some people develop serious side effects. In these cases, your doctor may recommend reducing your dose or stopping the medication.
Learn more about the side effects of Wegovy.
Nausea and vomiting
If you develop nausea or vomiting, it’s a good idea to talk with your doctor. Either side effect could be a sign of gallbladder problems or pancreatitis.
You might try the following home remedies to help reduce nausea:
- drinking small sips of cold drinks
- avoiding greasy or fatty foods
- eating bland foods, such as crackers, rice, or applesauce
- avoiding exercise after eating
To help avoid vomiting, consider smelling alcohol swabs.
Constipation
If you have constipation, you may be able to relieve it by:
- drinking more fluids
- exercising regularly
- increasing your fiber intake
Your doctor may recommend over-the-counter (OTC) treatments for constipation if home remedies are not effective.
Diarrhea
When you have persistent diarrhea, stay hydrated to prevent dehydration. It’s also a good idea to avoid caffeine and alcohol. Broths or sports drinks can help replenish your levels of electrolytes.
Some people may find that Wegovy is effective for weight loss. Others might not have any weight loss.
A 2021 study compared weight loss in people taking semaglutide and people taking a placebo. (Remember, semaglutide is the active ingredient in Wegovy. A placebo is a substance with no active drug or ingredient.) Researchers found that weight loss measured at the marker of 4 weeks was statistically significant in those taking semaglutide. They also found that weight loss reached its maximum at 60 weeks of treatment.
In other
- Weight loss at 12 weeks measured:
- 4% among people using 1-milligram (mg) injections weekly
- 5% among people using 2.4-mg injections weekly
- Weight loss by 28 weeks measured:
- 7% among people using 1-mg injections weekly
- 9.6% among people using 2.4-mg injections weekly
Wegovy is an FDA-approved medication for weight loss in people who are overweight or have obesity. You’re not likely to notice weight loss within your first week of treatment. But your doctor may notice changes in some of your health markers, such as your blood pressure or blood sugar.
You could develop side effects during the first week of treatment or later. The most common side effects of Wegovy affect your gastrointestinal tract and include nausea, constipation, and diarrhea. Side effects may improve as your body becomes used to the medication.
Your doctor may be able to lessen some side effects of Wegovy by adjusting your dose. Be sure to discuss adjusting your dose with your doctor rather than adjusting it on your own. They also might recommend OTC treatments for some side effects if you find that home remedies aren’t effective.
Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.